Tue, 19 Dec 2023 06:56:48 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16351 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16351 Wed, 04 Dec 2019 14:46:32 +0000 LoftDIY87
Whilst putting insulation in I've discovered he hasn't left ventilation at either end of the cold dormer roof. It's felt on top, with 150mm (145mm) ceiling joists, plus firrings. Am using 120mm Celotex in between joists, with 25mm Celotex underneath. Taking the firrings and 120mm Celotex into account, the ventilation gap (between top of insulation and bottom of roof OSB) spans from 63mm at one end to 33mm the other end - I know, a little less than the recommended 50mm ventilation gap, but that particular detail is the least of my worries at the moment! Because...

I've already discovered severe condensation when I removed one of the roof insulation boards and found the dormer roof OSB wet to the touch! The top of the ridge beam is also wet to the touch.

I know it will be (relatively) easy enough to vent at the far end of the dormer roof - using soffit or fascia vents. However I know I need the air to circulate i.e. vented at both the 'far' dormer soffit end, as well as the ridge end. Am toying with the idea of mushroom vents on top of the dormer roof, but there are 13 openings and obviously I don't want 13 mushroom vents on my dormer roof! (would need one for each opening as there's currently no way for the air to circulate between them)

I'm also thinking I could notch and drill holes in each and every joist to the maximum regulations permitted, that would create some sort of airflow in between joists, and possibly result in needing far less mushroom vents? (could I get away with just 3 - one in the middle and one at each end?) I've attached a diagram showing joist holes and notches I've calculated. I'd have to batten 44mm x 44mm timber to the bottoms of the joists and bring the 120mm Celotex down to that level to allow for 30mm holes to still have the required 50mm height clearance from the hole to the top of the joist.

Also concerned about the roof leaking if I get a roofer to put mushroom vents into a felt roof, whether it's 1, 3 or 14...

Any other solutions to provide ventilation?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16560 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16560 Mon, 18 May 2020 20:50:32 +0100 mitchino http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16524 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16524 Sat, 18 Apr 2020 18:12:40 +0100 Nick Parsons
I'm installing drainage membrane and perimeter drainage to deal with moisture, and insulating with 50mm PIR below a floating floor and 50mm on C-section metal studs to the walls to make drier storage space. Ceiling (floor of room above) has 180mm of flexi wood-fibre with a lambda of 0.039W/mK.

Approved doc B suggests I need 30 mins FR. I had planned to use 1 x 12.5m Gyproc Fireline, skimmed, to walls and 2 x 12.5mm to ceiling. Does that seem right to any of you who have recently done similar work? Part of the cellar was 'converted' to a 'garage' over 30 years ago by a previous owner (B. Regs approval applied for, although not sure if it was ever signed off), and the ceiling they installed was 2 sheets standard 12.5mm pl'bd, skimmed. That was installed badly, and has been removed.

I may have to download the 'White Book' from BG, but it sounds like that may contain more info than I can process!

Thanks in advance for your help.

Nick]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16543 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16543 Fri, 08 May 2020 15:19:53 +0100 Victorianeco
We don't need space so a full dormer not really what we're after. What are people's experiences with maybe a set of French doors and a small balcony or maybe even one of those balcony veluxes or equivalent.

It would be quite nice to have an 'upper deck' as opposed to an extra room so to speak.

Any thoughts or preferences?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16070 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16070 Tue, 19 Mar 2019 02:27:40 +0000 wookey
Question is, what's the best way of doing this? It's easy enough to add a row of bricks along the size to make it 220m smaller, but windows are attached to the wall and rely on it being solid. How does one tie the bricks in well enough to support the window fixings properly? Do I need to cut out the half-bricks and tooth them in (sounds like work). Or use one of those channels that bolt to the wall? Or drill in ties of some sort that go in the mortar layers? Suggestions welcome.

This is also going to have to be a summer job, because now there is along pause between taking out the old window and putting the new one in (whilst one changes the size and waits for it to set). Not much to be done about that...]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12763 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12763 Sat, 08 Nov 2014 21:06:08 +0000 RedDoor http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16509 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16509 Tue, 07 Apr 2020 10:46:34 +0100 Victorianeco
16mm UFH pipe will be used

And can it just sit on top of the PIR or does it have to be raised further?

Also can each sheet be cable tied together or have I got to use wire ties? Or do they even need to be tied together?

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16495 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16495 Tue, 17 Mar 2020 08:29:21 +0000 gfletcher We had some engineered softwood windows installed around 7-8 years ago - they were factory finished with microporous stain. They are due for being re-painted and I am considering other options including Linseed Oil paints. I am struggling to find someone locally - we are in Leicester - who has experience of using them. Does anyone have any suggestions? Also, I would like to see some windows which have been painted using the linseed oil paints - the problem that I have is that the people who sell the paints say they are amazing, but they would - does anyone have any suggestions of independent reviews or places to see it having been used?

Cheers,
Gavin]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15868 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15868 Thu, 20 Sep 2018 19:34:29 +0100 cczmark
We have a 30's house with un-insulated sloping eaves as per the detail below (not identical but pretty close) and photo. Seems to me there are 3 options to insulate.

1 - Remove plasterboard and insulate from underneath (i.e inside rooms) - Not doing this as way too much disruption and mess
2 - Remove tiles and insulate from above - requires scaffold, possibly difficult?
3 - Insulate from inside attic - some constrained access, generally unpleasant work and difficult to tell if there is no gap at the bottom (defeats the object..). See photos.

Ideally I'd like to do 3. Any suggestions - methods, materials, tips, etc. Is spray foam an option (DIY or professional)? How to maintain ventilation (plastic eaves ventilators)?

This may have to be a DIY job as my contractor has quoted a stupid price :-(

Thanks,
Mark.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16151 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16151 Wed, 12 Jun 2019 21:59:10 +0100 wholaa
I have a 2016 built semi D Irish house. It has double leaf cavity walls with drywall. In a few spots I have been able to see the behind the drywall and see holes in the inner leaf for electrical wiring. The inner leaf is parged but surely these holes allow huge amounts of cold air to enter and chill the back of drywall (see figure). Is it worth my while cutting holes in the dry wall and filling the leaf holes?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16489 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16489 Wed, 11 Mar 2020 09:10:00 +0000 Rigmarole
I hope you are all well.

Please bear with me as I may not get all the terminology right. I've been a long-time lurker on this forum, following excellent advice given by members.

I'm planning a warm roof retrofit, with sarking/rafters exposed internally (for an existing room in roof - which was converted many moons ago, and currently without insulation). The idea is to improve the property, which we are planning on staying in (it's been painful enough renovating to this point, so I don't plan on moving any time soon!). Price is a factor, as is relative ease of installation.

The reason we're not insulating from within is because I'm very tall, and just want to make the most of what little space we have upstairs (whilst dodging rafters).

My plan is, starting from the inside is as follows. The roof is a 35 degree pitch (if important), south facing on one side.

1) Existing 3-in Rafters (Traditional Cut Roof with Purlin)

(External)

2) T&G WISA Sprice Flooring as Sarking (18mm - to make installation easier - to be exposed from the inside, so this is also a cosmetic choice, as well to give good racking strength/still be simple to install)

Insulation is still undecided:

Either:
3a) 110-120mm PIR (for price/not decrement delay - I've got a reasonable price on the un-foiled variety)

or

3b) 100-160mm Wood Fibre - Sarking Board (for improved decrement delay - not looked into the price yet, but seems pricey)

4) Counter Battens
5) Battens
6) Pantiles

Eaves to ridge ventilation above insulation.

There are few dormers to factor in, plus a balcony cut out of the roof from one dormer.

We can add some insulation in between the rafters, if absolutely needed, but wanted to avoid this if possible. We definitely cannot add anything on the room-side of the rafters (again for headroom).

I've not yet worked out the nitty gritty, like fixings and membranes. Though have been making my brain hurt by reading through steico/super-7/celotex etc technical documents!

But am wondering if something like above could be feasible (with a few changes probably).

Many thanks,

Jonathan]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16459 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16459 Wed, 12 Feb 2020 08:25:23 +0000 peaks_ccb
(Sorry, I posted this to the wrong category earlier)

I've seen the previous messages on this topic but none seem to apply to my case.

I have an unused chimney stack in an uninsulated external wall, feeding two decorative fireplaces, with pots intact (no caps at present). I'd like to insulate the breasts and stop draughts. My loft is converted and I have a pir-insulated roof.

I've seen suggestions from Tony covering cases where the loft isn't converted, suggesting airbrick in loft and blocking chimney at ceiling level. This doesn't apply as I have a warm loft.

Should I stuff insulation into a bag and push this through pots to at insulated roof level, plus install vented caps? And then leave flues open to the fireplaces? Or fill flue with eps beads - and if so, down to a vented register plate just above the fireplace?

Thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16469 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16469 Fri, 21 Feb 2020 08:42:54 +0000 Dominic Cooney
Barn Conversion - 450mm thick stone walls, IWI with 100mm PIR insulation going in.

I need to put some internal walls in to divide off the downstairs Toilet and Utility/Plant room, I was thinking these would be good in 100mm concrete block, to provide better sound deadening and so that they can provide some additional support to first floor joists (might help with awkward staircase design).

What sort of detail would folks use where these walls join the external stone walls? Would you normally expect wall starter/butterfly ties into the stone walls to add stability to the blockwork?
I'm thinking the IWI should continue past the end of the walls to avoid a cold bridge?

Would you use a denser insulating product such as Compacfoam and fix through it to the stone?

Any thoughts gratefully received. (e.g. just build timber stud walls, easier to run pipes and cables etc. anyway!)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16415 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16415 Thu, 23 Jan 2020 14:06:46 +0000 modernvictorian
Having decided I needed it and would aim for 'as airtight as possible' I have obtained quotes from two companies. One specialist Eco type company and the other more of general ventilation specialist. The price differences are massive. The more expensive quote is twice the price. I am wondering if the higher costs really do translate to a better performing system? On the one hand I am hearing about overly noisy systems with plastic ducting that fails after 10 years, and on the other hand I am hearing that 'its just a fan in a box don't pay over the odds'. Does anyone have any real-life experiences they could share?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16335 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16335 Mon, 18 Nov 2019 17:41:29 +0000 deniance Ok so.....
Few years back I insulated the attic with space roll, you know the stuff with orange plastic on the bottom and perforated silver over the top of it, well I rolled that out between the joists, then I got the big blanket version of it and put this 90 deg over the first layer

This quickly developed drips of moisture everywhere , like someone had been up there with a hose pipe! And this was dripping off the roof onto the insulation ,

So I installed those white plastic roof felt spacers into the overlaps of roofing felt, about 50 of them! This cleared the problem up in a few days, along with sealing cables and pipes and holes with foam and sealant.

Well anyways, just been up the loft to sort the insulation out because it’s a bit of a mess and been disturbed, and whilst everything looks dry and a million times better than it was I stuck my hand on the silver insulation at bottom of the pile and it felt damp and cold, so I opened the silver perforated layer and stuck my hand in, and yep it’s wet!

If I had to give it a description I’d say it’s 95% dry and just the top most 5mm is slightly damp

So what do I do now? I was going to put the second layer back over it but thought I’d ask the experts first!
It’s an old stone house, with big standard plasterboard nailed to the ceiling, with pink plaster and white emulsion
I pulled the bag of insulation out of the gap and the plasterboard is bone dry, the rafters it sits in Look dry, the felt above it looks dry, the bags weren’t stuffed into the eaves really but I’ve looked down the eave and that’s all dry, my house doesn’t have eaves

So my thinking.... cannot be dissipating through the ceiling because the apace roll has the orane vapour plastic on the bottom, so either it’s still damp from before when I had the damp issue (4 years ago?) or ??

Any help gladly appreciated guys, before I mess it up again and have brown stains all over the ceiling cheers!!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16451 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16451 Thu, 06 Feb 2020 15:16:06 +0000 MatBlack
I think it would be beneficial if I took the EWI down to the footings. As its a solid brick wall, with just 2 steps of corbel like brick footings, would I comprimise the force pushing in against the wall.

Could the EPS still provide the necessary force needed when installed? ( I would install it bit by bit)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16395 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16395 Fri, 10 Jan 2020 16:58:41 +0000 WeeBeastie
What's the max depth of void that would be sensible to fill?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16436 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16436 Fri, 31 Jan 2020 14:04:09 +0000 Dur
This will be on the gable end wall , single storey, about 8 m long and 2 m wide and will be for utility/boot room/hot water tank type stuff with a shallow pitched roof - the finished outside height being c. 3.8 m.

Somewhere I saw a suggestion that an externally insulated block wall would be a better bet than standard issue cavity wall so started to look for more detail. I now know that there are many variations on a theme but apparently no standards so I am not really any the wiser. In fact overwhelmed bu options and materials and jargon I am not familiar with...

We need a render finish outside and can't really go very much more than 300 mm wide because of a side access.
The suggestion I saw said 100mm blockwork with rendered over insulation outside. But it seems that this is not going to get past BC, at least without a SE going some calcs. I have been looking for some more formal description of the build up, how it works with foundations etc but without success.

I guess I could easily be accused of guilding a rather old lily with this house which is currently about as air tight as a collander, but I really want to do the best I can where I can afford to plus the extension will end up being an area where I don't have to add IWI to the 9" solid walls, which is a good thing!

I mentioned the external insulation desire to the architect and he seemed concerned that there could be problems with render cracking / expansion joints etc.
The old solid walls I have assumed are at about U value of 2. The insulation we are fitting upstairs I hope will achieve better than 0.18.
Is this sort of level achievable for the new wall within the parameters mentioned?

Any thoughts to help simplify this and point in the right direction would be very gratefully welcomed.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16425 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16425 Tue, 28 Jan 2020 12:11:18 +0000 WeeBeastie
Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16411 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16411 Wed, 22 Jan 2020 09:49:36 +0000 MatBlack
My walls are solid brick, soon to be lime pointing again. Lime plaster on woodfibre insulation in parts, and possibly eps ewi on some external walls.

I would like wet UFH, and was set on glass foam (150mm hardcore in already) then ufh set in a 100mm limecrete slab. - throughout the entire lower floor.

Now I'm pulling the trigger on ordering, money is talking and I can see the huge difference between this system and an eps/concrete slab.

So my question is, all things considered with measures to let the walls breathe as much as possible, would a eps insulated concrete slab with ufh ever really give moisture problems up the base of the solid brick walls??

Many thanks for any experiences in this situation.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16412 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16412 Wed, 22 Jan 2020 22:22:42 +0000 ajdunlop I'm thinking about what to to between the joists.

In the back of the house I dealt with this by cutting away a section of ceiling in the ground floor room and inserted mineral wool and used an airtightness membrane and tapes. This worked fine but was a bit fiddly and meant the ceiling had to be put right after.

This time at the front of the house I am doing the first floor room 1st so was trying to think of ways to deal with between the joists from above.

Our house is an end terrace so I have to deal with two walls in each room and with that two directions of joists. I am trying to work out how to extend the insulation down between the joists and specifically what to do with the floorboards (these are exposed).

This is easy for the wall where the joists are at 90 degrees to the wall, cut slots for each joist in the insulation then reduce the width of the floorboard along the wall as required.

The problem is the wall where the joists are parallel to it. No slots required in the insulation so that's simpler but what do I do about the edge of the floorboards? They will be unsupported if I have to cut them back to allow the insulation to go bellow floor level.

If it is too difficult I will leave it and do the same as the back of the house when I tackle the front ground floor room.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16299 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16299 Tue, 22 Oct 2019 21:37:41 +0100 MatBlack
Stumbling upon this forum has been a great help in getting ideas for our home renovation. We have bought a 1905 semi thats in need of a lot of tlc - damp, rotting floor joists, leaky roof, tanking plaster, cement mortar to name just a few issues.

First jobs will be to make it watertight - new roof (with loft conversion), fix guttering and divert water with french drains. Then repoint with lime mortar (solid walls), and new sub floors. Then knock all the tanking plaster off and install wood fibre internal insulation and lime plaster. Then on with rewiring/central heating etc.

With the 2 reception room floors however, I cannot decide whether to replace the floor joists and insulate, or go for the foamed glass with limecrete and ufh. Its a 700mm void, so the glass is expensive. But in the long run the heating efficiency may pay off - its just that Ive read some accounts of nightmare installations with the glass insulation!

So anyway, looking forward to being a forum member, hopefully I may be able to give some help one day once this renovation is done.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9318 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9318 Mon, 09 Jul 2012 15:35:31 +0100 DamonHD
We decided that this year's fun is going to be replacing all our old/blown double-glazed units with triple-glazed, and happily our friendly local glazier will now do 3G from their supplier Whiteline.co.uk with the additional thermal break and glazing flipper to get to Uw = 0.8E/Km^2 (PH compliant).

Any comments on this supplier or design?

Also, I'd quite like to (re)fit the Enviroform aerogel reveal insulation to minimise thermal bridging (we already have some round 2 upstairs windows that would be replaced and are in the aerogel dry-lined wall).

Am I wasting my time?

If not, should I have the glaziers do it, or have my builder come back and do it?

I have already stressed the need to be very careful about air leakage and damaging the aerogel.

Two or three of the replacement windows would go in the wall that we have not yet dry-lined, so I assume that we wait until we get them drylined to get the insulated reveals if we do them?

Rgds

Damon]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16378 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16378 Fri, 03 Jan 2020 16:24:26 +0000 dereke
I've had a look and the house is on the boundary with the neighbour whose driveway runs alongside it with a small gap between. The ground between the house and the driveway is about 50mm below the driveway. The mortar at the base of the wall is cracked, crumbly and in some places missing. The render generally looks OK.

My theory is that when it rains heavily they are getting a lot of water sitting around the base of that wall and it is soaking in and causing the wall to be damp.

Is this a crazy theory? Any other ideas for what could be going on?

I'm trying to attach some pictures..]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16376 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16376 Sun, 29 Dec 2019 17:37:53 +0000 rosecottage
I am completely stripping the roof and as I do I want to plan for EWI. I was hoping I would just be able to extend from existing rafters but they stop close to the internal wall and the previous tiles (last row) were cemented on to give the previous overhang.

Does anyone know of a trick to increase eaves without extending from the existing? I thought about putting a vertical wall plate on, but the issue is we have some brick detail so there isn't room.

Searched for diagrams but can't find anything.

Then I will be starting on the gable ends, but I think this will be a simple notch and ladder? Though I haven't seen many done with flush gable end chimneys...

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16342 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16342 Sun, 24 Nov 2019 06:29:29 +0000 WeeBeastie
The insulation may be a novice DIY job so I'd prefer not to be working around lots of wiring. I'd also like to have the option of fixing rigid insulation boards under the joists, in addition to the quilt + netting between.

My electrician says he would normally put the wires along the bottom of the joists, but this would conflict with the fitting of the rigid boards.

In an ideal world I'd somehow have all the wiring above the floor, but this seems difficult and expensive. I know of the rebated skirting boards but these are mdf which I'm hoping to avoid. One (discarded?) thought was to reinstate the picture rails and tuck wires in above these and then drop down, but some walls are solid so there would be a lot of chasing into the wall.

So do the wires just go further up the joists? Any thoughts?

Thanks again.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16372 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16372 Fri, 27 Dec 2019 10:06:58 +0000 Victorianeco
Steels
Walls knocking through
kitchen refurb
Extension build up
New roof etc etc

Given the little additional benefit this would bring us we were thinking of a small 'lean to' accessed from the door coming off the middle room, it would only be to store washing machine, tumble dryer, clothes to dry.

We'd like to have as much light as possible as this area lights up the kitchen and middle room at the moment.

Thoughts on build up?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16363 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16363 Tue, 17 Dec 2019 14:53:34 +0000 Phil & Colette
We are planning a refurbishment of an 1850s sandstone building in North Yorkshire. While doing some opening up to see what is there we removed some plasterboard from above a window reveal. The inner and outer leaf are well supported on 170mm deep concrete lintels but the rubble core inside has a triangular defect running about 450mm up from the reveal level. roughly the same shape and proportions as a piece of toblerone.

The window is not original but was put in sometime between 1940 and 1990 along with 2 others we have not opened up yet.

The question is how to deal with this. I would anticipate lime mortar and sandstone rubble gradually built up, with some form of either temporary or permanent supports to hold it in place, and how should it be finished to prevent further collapse. The final finish is probably going to be insulating lime plaster.

Any thoughts or experiences gratefully received - already worked out will want seriously good eye protection!

Phil]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16357 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16357 Mon, 09 Dec 2019 10:35:49 +0000 jerseyman For insulation he has specified rock wall between the joists, but as far as I can see, by the nature of eco-joists it is going to be pretty near impossible to get a complete thermal barrier this way. Is any one aware of a standard or recommended approach for insulating eco-joist floors? Or is the rock wool approach OK?

Thanks for any help]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16364 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16364 Tue, 17 Dec 2019 15:20:37 +0000 Davycrocket
The construction around the front facing windows of our home has 3 windows which, internally, are "inset" into the front elevation.

Typically the front stonework is approx 450 mm thick, but where the windows sit the stonework is approx 200 mm thick and very cold with it.

I intend to flush the walls off with a small studwork partition, in line with the thicker parts (450mm) so that the bay, if that's what its called is removed.

My question is, what should I use to insulate the newly created void ?

I'll use cls timber for the stud and probably cap them off to form the windowsill with u pvc or timber sills.

Is this a good form of insulating works or are there other methods I should consider ?

Thanks

Dave]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16358 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16358 Tue, 10 Dec 2019 10:51:29 +0000 Davycrocket
I have owned an 1800 stone / rubble end terrace house for 10 plus years and have fell into the cement based render / gypsum based plaster trap/

Scaffolding has gone up and down more times than I care to remember in an attempt to stop the rain ingress, cracks have been filled, painted over and so on and so forth.

I'm now having read this great forum considering extending the verge and then insulating from the outside, then finally cladding be it slate, timber or upvc.

The trouble is i want to do this right first time having in the past winged it.

Are there any threads or documents etc detailing this kind of works available to read or could some kind soul advise please ?

Once that is done i Intend to also insulate from the inside if necessary ?

I've read about vapour barriers and wondered if that wouuld be the way to go or should it be lime plastered with maybe hemp or similar added for warmth.

A lot of questions I know sorry but I'm hoping this will be the last time I have to scaffold the building !!

Thanks in Advance

Dave]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16362 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16362 Sun, 15 Dec 2019 07:12:53 +0000 WeeBeastie
What could this vent be for?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16338 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16338 Wed, 20 Nov 2019 14:50:41 +0000 WeeBeastie
Single storey so wouldn't take too much fill.

9" solid brick walls which become thinner to the back of the chimney. I hope to add EWI at some point in the future.

Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16339 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16339 Thu, 21 Nov 2019 21:15:53 +0000 dereke
While I've got everything up I was thinking about installing some UFH. I understand the aluminium heat spreader plates are quite good. However my joists seem to be at between 320 and 360mm between centers. The narrowest spreader plates I can find are 390mm. I don't really fancy cutting them down to size with tin snips.

So is there somewhere you can get narrow spreader plates or is there anywhere that hires out metal type guillotines? Or is there some better alternative?

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16318 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16318 Thu, 07 Nov 2019 13:43:08 +0000 WeeBeastie
This topic again...

I'd appreciate your thoughts on the best way to insulate floorboards from below, and indeed whether I should do this.

I have a void of 90cm at the front of my property increasing to 1.3m at the rear, with several access hatches of varying size. The floorboards are well finished and have tight joints so I'd like to do this without disturbing them.

I've read the various threads here on the subject but usually the situation involves a shallower void where the boards are to be lifted, whereas I'd like this done entirely from below.

Also, any words of experience on the difference this makes to comfort? Any real-life condensation/rot problems? This wouldn't be a DIY job for me and I'm concerned about spending my limited budget judiciously, so want to be certain it would make a significant difference.

Other info: 1930s semi-detached bungalow, east coast of Scotland. 9" solid brick with painted harling, lathe & plaster inner. Loft insulation and DG in place. Reluctant to do EWI or IWI for various reasons.

Many thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16310 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16310 Thu, 31 Oct 2019 14:10:48 +0000 Nanuchka I have really enjoyed reading the posts here, and am now seeking some guidance with a question of my own...
My house is semidetached with the standard layout of front and back receptions (now one room), hallway running through the middle adjacent to party wall, and kitchen at the back. The reception room has a suspended floor, abutting the solid floors of the hallway and kitchen. The two outside walls of the reception room, which are at right angles to one another, have four air bricks along the side, one at the front. The air brick in the wall at the back which would have created a cross draught has become part of an internal space when the kitchen was extended to the full width of the house at some point.
The reception room floor is beautifully finished in engineered oak, and sadly uninsulated. The tops of the air bricks are slightly higher than floor level, and plenty of air gets through above the floor in spite of my attempts at sealing. My question is: would it be feasible to block up the air bricks and install some kind of mechanical and controllable ventilation under the suspended floor to make the conditions more comfortable? I know a piecemeal approach not ideal, but I don't have the resources to do huge amounts of work. I would also like to switch away from gas central heating and I understand that air source heating doesn't work too well unless house is well-sealed so it would help with that too.
Thanks for reading :-)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8248 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8248 Wed, 07 Dec 2011 11:00:07 +0000 rhamdu
But it had never really struck me that in an old house, this is a losing battle because the soil or 'oversite' is normally damp and therefore a massive source of water vapour. Then a friend told me that since he laid polythene on the ground under the floorboards, he had fewer damp problems. Even rising damp in the walls had abated.

I've now done the same - so please don't tell me it's a bad idea! Actually, do tell me, if that's what you think.

Is it orthodox practice? Has anyone had a good or bad experience with this?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16327 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16327 Tue, 12 Nov 2019 12:13:17 +0000 kaeko
We are renovating our house in Normandy, France (possibly mid-late 17th to early 18th century) and looking for some guidance on best way forward with the new kitchen floor.
Not had much luck so far finding what feels like relevant information online, I'm no builder and the builder (my dad) is new to using lime and underfloor heating, so any recommendations welcome.

Situation:
- Semi-detached house on a slight slope (neighbour is uphill so to speak)
- Earth floor (scraped back and levelled, trenches dug out for plumbing and electrics)
- Laid a 10cm thick cork granule and lime slab (ratio 2 cork to 1 lime) on top
- Walls have no foundations to speak of, so couldn't go dig out any further, on neighbour side wall we were 10cm below the wall in places…
- Walls are crumbly, stones barely held together in most places, so doing a lime/cement skim, then wood fibre insulation with plasterboard skin.
- Idea/aim is to have underfloor heating, electric, in a lime screed of 4-6cm.

Questions:
- Do we definitely need insulation around the wall edges?
- Is the insulated slab enough insulation under UFH/screed (I gather from the way it was done that it equates to having 5cm of cork boards) or do we need something on top of slab?

TheUFH thermostat sensor needs to be below the heating elements, slab is mostly dry now (7 weeks old, told to wait 8 weeks as it's been so wet):
- Do we lay a 1-2cm screen to put sensor and get a better level to support the heating elements?
- Is that just complicating things, should we have planned small trench in slab?


Sorry for all the questions, hope I'm making some sense and many thanks in advance.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16312 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16312 Mon, 04 Nov 2019 00:07:28 +0000 Yalch
We have now decided to tile this floor and I was wondering what the best way to do this would be?

A couple of options I've heard are:

1. Adheisive direct to the spreaderplates/pipes and then the tile onto that.
2. Backerboard of some sort (maybe ply) and then adheisive/tile
3. Adheisive direct to the spreaderplates/pipes and then an uncoupling/decoupling membrade, then adheisive,then tile.

Thanks in advance :)
Jon]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16324 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16324 Sun, 10 Nov 2019 20:09:47 +0000 WeeBeastie
The two bedrooms and bathroom suffer from condensation on the walls. I'm hoping with the 'plastic' paint finish removed the lime plaster walls will be able to buffer moisture enough to help remedy this problem (though I know the best solution is to make the walls warmer, but EWI or IWI is not currently on the cards).

So two questions:

1) Am I correct in my thinking? I suppose the result can't be any worse!

2) I dislike wallpaper so my first thought was to paint directly on to the walls with clay paint which has some hygroscopic quality. I have some Auro 331. Then I revisited Simon James Lewis's Bristol Hemp & Lime website and he recommends using lining paper then clay paint. Obviously this means you could in the future take the wall back to the untreated lime finish, but is there any particular reason that I shouldn't paint directly on to the plaster with this type of paint? The wall would still be vapour permeable.

Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10247 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10247 Wed, 06 Mar 2013 15:40:54 +0000 andyman99 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16316 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16316 Wed, 06 Nov 2019 16:00:09 +0000 i_DaveJ I'm planning to fill the void under the ground floor boards with insulation (possibly loose fill cellulose) and add EWI which will be taken down to the footing, beyond the DPM and blocking off the air bricks. The under floor space is dry (based on observation) but I am wondering whether to seal the concrete and bricks under the floor with a sealant. The floor boards will be coming up so I can access the void to apply the sealant.
Thinking of a crystalline tanking slurry that can be applied with a brush (or sprayed on but I don't have a sprayer).
There's a couple of brick courses under the dpm and a concrete slab which I assume has been laid on sand without a damp proof membrane.
I'm in two minds. Is it better to leave the space to breath or damp proof? I guess I'm worried about damp in the insulation as there will be no ventilation of the void.
Appreciate any comments, thanks...]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16315 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16315 Wed, 06 Nov 2019 13:11:07 +0000 jemhayward
Can anyone see any problems with this approach?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16252 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16252 Sat, 21 Sep 2019 17:17:13 +0100 HoveTom
More sockets than I think? Position of? Any particular type of socket? I’m not massively into smart home gadgets but assuming this rewire will be with me for sometime anything simple I can ask the electrician to do to future proof my house without it costing the Earth?

I don’t want to start a thread for smart home fanatics about the best way to set up home network cables or WiFi devices as that’s a separate subject ( ish ) as I’m presently planning sockets looking at my house plans, but, any and all advice on first fix electrics appreciated.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15494 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15494 Thu, 11 Jan 2018 11:43:43 +0000 PlHadfield
The floor is of 140mm x 18mm (5 ½” x ¾”) tongue-and-groove softwood boards. We lifted a few boards three years ago around the edge for electrical work prior to re-decoration, and that was the moment at which we thought we should consider what else to do while we have them up, in order to avoid lock-in of poor insulation and air-tightness down there. This would then be the first stage of the step-wise retrofit which we had been beginning to contemplate, to as high a level as can be justified by the likely-achievable whole-house air-tightness, and by the longer-term depth of our or future owners’ pockets. Those edge floorboards have remained up, and we have been without a sitting room, while we pondered the right way forward ever since.

Given that we aren't sure whether we'll stay here for more than a year or two more, but may be here for forty years, we are hoping at this stage to take a sensible view ourselves about where the future air-tightness layer should be for the house as a whole, which will inform what we do in this sitting room floor void (and with the ceiling joists of the same room) in this first stage, to avoid lock-in. We’re hoping we can thereby avoid having to have a costly full retrofit plan drawn up professionally at this stage, in case we don’t stay and so don’t take the retrofit much further ourselves. The house is a detached, two-storey, 1955-ish cavity-walled construction, both external wall leaves being of brick, and with Rockwool mineral insulation blown into the approx. 65 mm (2 ½”) cavity between them by Miller Pattison 13 years ago. Including the internal garage (ripe for conversion to living space) it weighs in at approximately 140 m2 (1500 ft2). We are in a conservation village, but our brick is undistinguished, and the neighbouring property is rendered, so we believe there is a good chance that rendered External Wall Insulation (EWI) will be allowable. We are west facing, in a sheltered position but somewhat shaded (from at least the midwinter sun) by trees in almost all directions, especially (and from the summer sun too) by a very large and historic ash tree just outside our property at our south-east corner. Photos attached, I hope, showing amongst other things garage doors suffering from planning blight until we decide whether to convert the garage.

Ideally we’d hope ultimately (if we stay) to insulate the perimeter down to the footings as part of a future EWI, sealing the airbricks, and bringing the 270 mm (10 ½”) underfloor void into the conditioned space of the house by heating it, and ventilating it into the interior. The suspended timber floor is to the sitting room and also the hallway, which are about half of the house’s total footprint, the rest being concrete slab on grade (garage plus kitchen/ dining area). Currently the suspended floor appears to be adequately ventilated via air bricks to the great outdoors.

A plan for a future EWI is also attractive because the slab under the rest of the house, namely under the kitchen/dining room and the built-in garage, is we believe un-insulated, so the idea of cutting the thermal bridges at the perimeter of that slab with EWI down to the footings seems sensible there too, as well as saving the internal joinery work which would be required if we instead insulated on top of the slab. (We do have sufficient ceiling height at 2.44 m (8’) to do some of that perhaps if we had to, but hoping not). By insulating externally down to the footings we’d hope thereby to bring the subsoil beneath the house into the thermal mass, warming it up over several years. Since we’re on very heavy (Lias) clay with we hope no major granular intrusions, we’re hoping that that warmth will not be whipped away by water moving either vertically or horizontally to any significant extent in the ground below us (to paraphrase FosterTom in another post on this forum).

But that may be a vain hope as we have a shallow perennial stream defining our garden boundary at the sitting room (southern, gable end) side of the house, which rises in a spring at our south-eastern corner. It runs the full length of that side of the house, only 1.5 m (five feet) or so away, at its nearest, from that gable wall. Its normal winter water level is 480 mm (1’7”) below the level of the ground adjacent to the wall (see attached ‘South wall and stream section’ detail), which makes it 600 mm (2’) below the lower surface of the 100mm (4”) thick concrete (rat pad?) which lies below the floor, 820 mm (2’8”) below the lower edge of the lowest of the five or so courses of blue bricks which seem to form the damp proofing of the outer leaf in that wall, and 980 mm (3’3”) below the internal wall leaf’s DPM. Flooding of this stream once or twice a year raises its level by 400 mm (16”) or so, due to inadequate culverting under the road outside, but it normally subsides within a day or so back to its normal level once the very heavy rainfall stops. It never gets higher because at that point it can escape over the top surface of the road, to its much lower stream bed on the far side of the road. When the stream is in spate in this way, the water level in a 0.6 m x 1.2 m (2’ x 4’) trial pit I have dug down through the concrete path, adjacent to the external face of the foundation wall, was just 370 mm (15“) below the lower surface of the concrete rat pad. But what the true water table level is under those conditions inside or indeed outside the foundation wall we have no clear idea, and the floodwaters were only inches from the edge of my trial pit, so that water didn’t have to travel far through the uppermost clay near the pit’s stream-ward side to pass into it. And the water level in the pit, after being so full, takes some time to subside back down to its normal water-table level of course. Probably I should bale out the trial pit as soon as the stream flood outside it has subsided, and leave it for a day or two to stabilise again, to assess what the true water table level is in there at that point. I will do so at the next flood event.

Maybe the proximity of this stream is why the rest of the entire outer wall leaf of the house seems to be of what I suspect are Class B engineering bricks (red, very hard, and measuring unusually 225 mm x 108 mm x 70 mm or so (9” x 4.25” x 2.75“) except on the rear extension, where they are standard size).

Our first thought for air-tightness was for the internal wet plaster layer to be the air-tightness layer, with attention to sealing and taping up all joists where they go into the inner leaf, and to sealing all other penetrations such as electrical sockets. In support of this, with some edge floorboards up we could see that the suspended timber ground floors have all their joists supported out, away from the supporting (inner leaf of the) walls by cantilevering them out from the inner leaf of the cavity walls, and from the internal structural walls, on blue engineering bricks. So these ground floor joists don’t penetrate the walls at all. So we would have fewer joist penetrations to seal, if we were going with this air-tightness plan, as only those at ceiling/ first floor level would need to be sealed. I find too that we can actually jack up each individual joist by a few mm, so could perhaps work a membrane underneath each one by one, and between them and the walls, We imagine that this cantilevering arrangement may have been used because of the proximity of the stream, in order to minimise the possibility of wet walls causing the joist ends to rot. (to be continued)…]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16288 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16288 Thu, 17 Oct 2019 10:12:34 +0100 Yalch
I've got an underfloor Heating system in my dining room that I've put into the Limecrete screed and am putting wood on top.

The water currently starts at the boiler (Manual, not smart), runs to the mixing valve through the pump round the system with auto actuators on and so on, with a return to the boiler etc...
(this is the pump and Mixing valve I have: https://www.theunderfloorheatingstore.com/manifold-pump-mixing-valve-unit)

anyways I've read that its best to keep it on low constantly and then turn up the temp when you want to warm the room and best on a smart thermostat to do this with so it's warm when you're up. (I currently have it attached to a Nest)

My question is: Is this the most efficent way to run the system?
And if so whats the best way to automatically change the temperature? (would I need to figure out a way to get an actuator to fit on my mixing valve?)

Thanks in advance,
Jon]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16272 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16272 Wed, 09 Oct 2019 16:45:48 +0100 i_DaveJ We’re planning to renovate our 1960s bungalow and incorporate various energy saving features. One issue I have been grappling with is how to insulate the uninsulated drafty timber suspended floor, but, I am now wondering whether it is worthwhile.
We plan to insulate the external walls (EWI), likely with 90mm EPS finished with render. After lots of reading, particularly older posts here, we’re thinking about running the EWI down to the foundation to eradicate the cold bridge essentially making a shallow insulated basement (though I guess there is still a bit of a cold bridge at the base of the internal cavity wall where it sits on the foundation). I assume this will make the current suspended floor void part of the warm envelope. It will involve blocking up the air bricks and bridging the DPM - is this a sticking point for us and building control?
What led us to this decision is that the void under the joists is only 85mm (between the concrete slab and joist) so we can’t insulate under the floor and leave the 150mm to satisfy building regs if we were to take a traditional approach (which is what we were initially considering).
The idea is to trench around the house, insulate (fixed with adhesive) and backfill with LECA (including the foundation footing face).
Having done this, we could fill the floor void but the incremental reduction in U value might not be justified (going from about 0.4 to 0.15, calculated using CIBSE ). Ironically having no void arguably negates the need for the air bricks - so that’s a thought, it avoids the potential argument with building control about blocking the air bricks.
We want to improve the level of insulation and reduction in infiltration losses caused by the air bricks.
I’ve attached a section through the floor space (1:10). Not sure of the thickness of concrete slab or foundation footing thickness.
Thoughts? And thanks very much in anticipation of any responses…]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16274 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16274 Wed, 09 Oct 2019 19:22:13 +0100 Nick Parsons
I worked on a job a while back with high-spec timber 3G sash windows and yes, there was some leakage during the a/t test, and casements would have performed better, but the 'wind' did not whistle through in a/t test conditions.

I should have thought that a brand-new uPVC sash window should perform quite well. What would 'the panel's' expectations be?

Thanks,

Nick]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16268 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16268 Tue, 08 Oct 2019 13:43:41 +0100 mellowwhippet
The first priority is to improve the thermal properties of the roof. Am I correct that greening the roof with sedum/wildflowers would help with this (as well as getting a roof light that can open, etc)? As I understand it, the process requires several new layers of insulation and waterproofing on top of the existing roof surface which would help reduce heat absorption. The plants then do their bit to deflect/absorb heat.

The second priority is to bring the roof into the 21st century. So, greening achieves this but how about some mutually complementary mounted PV panels. Supplier tells me that I would need 6 at a minimum. Trouble is this doesn't leave a huge amount of space for the greening, so am wondering what the balance is. Would PV panels also help us with our temperature issue by deflecting heat off the roof in summer?

And finally, it's of course the south facing rooms of the house that get too hot in summer. Should this be factored into the layout of the roof, ie. what should be the roof surface (PV panels or greening) over south facing part?

Couple of examples attached if anyone is interested. Be really grateful for your thoughts.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16259 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16259 Sun, 29 Sep 2019 15:30:57 +0100 Justin
Due to work and other commitments the efficiency improvements to my house ground to a halt two or three years ago, and they need to be kick-started again.

I attach an image of the outside front. Nothing much to see there, Yes, it's dull. (But from the rear we do have 20 mile green view from our gorgeous elevated location :).

It’s conventional early 1970’s with medium block (that nasty black power-station tailings block), blown urea filled cavity. Original builders blessed us with their deep money-saving skeilings to the first floor, which, as was the way, they kindly filled with fresh air for us.
I added a new large wrap-round rear extension 15 yrs ago in brick and block which used 90mm cavity (60mm PIR internally to the wall), with additional 25mm PIR dry-lining. I have 3G (Adpol) timber glazing to the rear.
I’ve stripped out empty plasterboard skeilings through most of the first floor, and replaced with (eaves ventilated) 120mm PIR build up between and under, and I’ve internally dry-lined internal walls with additional (variously depending on the space) 50..100mm PIR. I have always taken as much detailed care as I possibly can throughout with meticulous VCL and sealing the PIR boards both to the wall and between as far as It’s been possible, even into the electrical outlets.
The massively inefficient internal garage has been sealed off on the internal house side with 100mm PIR to all it’s internal (single skin) walls, and to its ceiling also to the bedroom above. There are still cold bridges – notably floor penetrations and some window reveals, but the world (and my house), remains imperfect. I have not yet “treated” the top left room in this pic, It’s the cold one. Enough of the history.

Q)
Front windows you see are typical UPVC 1980’s nastiness and they need to go. Internally on the downstairs and upstairs (one room) I’ve already remedially insulated as above. I did what I could into the existing (solid) reveals with 15mm PIR (as much as would fit to the old window frames), but cold-bridging there is inevitably still evident.
Fixing the front elevation to do the windows will be a missed opportunity unless I take this deeper. I must for starters fix the tile hung zone. (Plasterboard-air-felt-tiles! lovely). Also to potentially to shrink the window openings by wrapping a better layer of PIR into the reveals. This would then tie up with – maybe- a breathable EWI and render to just this elevation*. Eaves aren’t generous, perhaps 120mm (asbestos board soffits), and the most thickness I could realistically add externally would be ~ 60mm including a render (If I render, that’s TBD, but a cladding may work OK.
I have an idea to swap the windows for single large pane downstairs (we scarcely open it), and to shrink the upstairs to a horizontal on the right and a vertical on the left. Maybe a single-room MHR ventilator downstairs alongside, to run probably only on winter nights when humidity builds up too much.

I have no mechanical ventilation, and (only if it becomes part of a plan), the sheer shortage off space would restrict to to upstairs rooms only, and even the there’s hardy anywhere to realistically for the fan without a noise nuisance. (Thank you, I am award of Viking House Fresh-r, and it’s been noted..).

I am bashing about ideas for most economical way to (A), shrink the brickwork openings, (B) to fill the empty timber void tile-hung area, and (C) to remove window reveal cold-bridges, and (D) maybe (or not) marry this with a breathable EWI if that becomes a good idea to hide the former. Weathering detail around reveals and cills is very much my concern, and how this could work with an EWI (which due to my internal alterations would be more of a breathable not-too-thick wrap, and to reduce the temperature gradient in the brickwork, rather than the full-blown thick EWI layer).

(*The North elevation (wall to the left) is 100% windowless elevation. Perfect, you might think for quick and economical EWI. Yes, want. The floor penetrations and condensation risk thereto would also benefit from that, since after my internal works, those do bother me just a little - However, neighbourly relations don’t lend themselves to any access whatsoever, either working there or to increasing the wall thickness this side. So that will need to wait. Whatever I do to the front needs to be compatible with and to connect into (future hopefully) an easy North elevation EWI upgrade.)]]>