Tue, 19 Dec 2023 06:54:33 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16832 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16832 Mon, 07 Dec 2020 11:54:02 +0000 cc64
I specified some high spec windows for a full on refurb of my terrace; the glazing has an R of ~2; the windows are installed using the Illbruck i3 '3 layer' system (external TP600 tape, middle FM330 PU foam, internal airtight but vapour permeable tape back to structural opening). Slow progress means the internal window ledges/boards and window reveals have not yet been fitted.

I'm now surprised that the cill carrier (a thermally broken undertray to the window which extends through to the inside edge of the window) is forming condensation beads. Room humidity is 61%. Outside temperature is 2.6C.

This alarms me; unless the installation of the window ledges/boards and liners becomes the air and vapour control layer I will have a pocket within the structure where interstitial condensation is likely. (This pocket has horizontal bounds [lower] of blockwork [upper] of window board, [outer] of window frame/cill carrier and [inner] plasterboard.) This would be unfortunate.

Are there any experienced window fitters here that can advise?

(The airtight but vapour permeable layer on this refurb is intended to be on the inner face of the block wall)

Thanks
M]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16835 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16835 Mon, 07 Dec 2020 18:56:14 +0000 LoftDIY87
https://live.staticflickr.com/65535/50691875426_9fa7f070fe_b.jpg

Had to hack off some of the multi finish on this one, what would be the best way to repair? The paper layer has also come off the plasterboard so I can't reskim the current surface.

Would it be blue grit and then multi finish?

Do I need to use Wickes Bonding Agent?
https://www.wickes.co.uk/Wickes-Ready-Mixed-Plaster-Bonding-Agent---3kg/p/221807

Or a bonding coat instead of blue grit?
https://www.wickes.co.uk/British-Gypsum-Thistle-Bonding-Coat-Plaster---25kg/p/220055

Could I use easi filler instead of multi finish?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16586 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16586 Wed, 03 Jun 2020 17:42:56 +0100 monkeywood
I'm very new to this forum and am beginning to slowly renovate my first home (1900 south-east facing mid terrace in Cardiff). Please excuse if any of my questions/comments seem dopey!

I have looked through a number of the discussions on here and many of the web pages suggested for newbies. I was just hoping for some guidance and things to think about when prioritising and budgeting. The amount of information is a bit daunting and I'm getting that "I don't know what I don't know" feeling.

I am currently getting very confused over various RHI/SEG/ECO support. I was considering approaching a sustainable buildings consultancy service for guidance/review (BREEAM/NEST)

My current EPC is 42 with issues seeming to be a lack of solid wall and floor insulation and electric heating for the shower.

I have been reading the suspended timber floor discussions with great interest as I am completely suspended at varying depths throughout. The loft has some insulation (EPC says 200mm).

I have had some tasks completed since moving in (February 2020) include replacing blown lights with low energy lighting, installing a new boiler (previous owners were using plug in electric heaters throughout the house), connecting as much of the water heating to the boiler (only shower supplied by electricity now), removing the gas supplied fires and overhauling the garden (think bee/butterfly paradise!).

My next plan is to refit the kitchen and lean-to utility. Is there anything you would suggest as a pertinent consideration for this? The floors in both rooms are suspended so providing that any damp problem further down the wall are sorted out - would you insulate the voids beneath?

I have looked into energy efficient appliances and lighting and plan to draught proof the doors and upgrade the double glazing to triple.

In terms of general housing renovations, any suggestions on where to start with a limited budget? Any comments or advice are gratefully received!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16089 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16089 Sat, 06 Apr 2019 12:39:10 +0100 wellburn In winter / heating season, could this easily (ie cheaply) be re-used?

I could let it go cold in the bathroom, but that would be bad bad bad for humidity...
I could maybe have a plastic cover over the bath, so it gives out heat as it cools down, WITHOUT releasing steam ....
What about having an old radiator in the room below, on the bathwater waste? - bath empties through the radiator, transferes some heat, used for heating the room below?
I imagine the ecosystem inside that old radiator could become quite unhealthy ...

Am doing a full refit, and just wondered ....
any ideas]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16727 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16727 Tue, 22 Sep 2020 17:11:38 +0100 Hadyn98
Some year back I tried to take advantage of the green deals by getting CWI. The guy came round and quickly said it wasn't feasible, due to excessive mortar in the joint, on the inside of the cavity (did he call it mortar snot?). It's a mid 1950's build semi-detached.

He checked all the walls to make sure and while checking the party wall in the loft space, I saw on his camera up draughts causing spider webs to be blown around. !

Does that explain why the party wall feels colder than external walls? When I measure the walls internally using infrared thermometer in winter, it's around 0.5-1.5 deg colder on the party wall. Built in cupboards against the party wall get damp and mould during winter as well.

My questions are:
1/ Surely air draughts in cavity walls are a problem. It's supposed to be a semi-sealed void to limit heat loss, surely?
2/ If that's correct, how could I seal up the cavity to prevent air flow? Even just preventing airflow without sealing the cavity should be an improvement?
3/ Is there any internal cavity insulation solution for walls with uneven mortar? As far as I can tell the cavity is standard 50mm.

The front wall has some local stone around the bay window (another problem he highlighted), the kitchen has been extended out the back wall, and there is a garage on the other side wall (which we will eventually be including in the living space).

We're in SW London if anyone is able to make recommendations.

Many thanks,
Hadyn]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16752 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16752 Sat, 10 Oct 2020 20:33:01 +0100 Victorianeco
Are there any standard measurements or general spacing rules to follow? Or just all by eye?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16822 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16822 Tue, 01 Dec 2020 21:10:52 +0000 Victorianeco
A few similar premises have a saltbox style roof, my thoughts are a flat roof would yield more usable floor area but waiting on planning for some outline pointers.

Any preference on roof style or roof covering? Building is approximately 10m x 10m footprint]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16793 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16793 Thu, 12 Nov 2020 12:16:04 +0000 lineweight
This relates to what I'd think of as the bog standard loft conversion here in the UK, hundreds or thousands of which are done every year. Commonly they'll be to a Victorian or Edwardian terrace or semi-detached house.

A few things that most of these tend to have in common:

1) Existing, timber-rafter pitched roof planes which are to be retained
2) A new-build "dormer" element which will have vertical faces and a flat roof
3) New structural steelwork which will be by necessity bearing onto existing masonry (whether party walls or external walls)
4) The existing masonry walls (in the main body of the house) will be solid with no insulation, and insulating them externally or internally may or may not be part of the project.

With any project, I like to start out with a basic strategy for the insulation: does it go inside or outside of the main structure. And I think most people here would agree, in principle, it's usually best for it to be on the outside.

However -

With a typical loft conversion, it's not that straightforward. There is a conflict between parts of the build where the insulation is better on the inside, and parts where it's better on the outside. I'd break these down as follows:

Arguments for insulation inside the structure:
- Any *high level* steelwork, bearing into solid masonry party or gable-end walls, can do so without bridging the insulation layer.
- On any existing bits of pitched roof which are to be retained, putting insulation inside of the rafters means you can keep the external covering (tiles or slates) and you can keep the external roof plane unaltered and re-use the existing rafters.


Arguments for insulation outside the structure:
- Any *floor level* steelwork bearing onto masonry walls can do so without directly bridging the insulation layer
- It avoids most worries about compromised VCLs and condensation within the construction buildup.
- Generally works best for any new-build flat roof elements (straightforward insulation on top of deck, easier to build, no worrying about ventilation above insulation layer, etc)
- In principle it's easier to co-ordinate with any external insulation to the main walls of the house.


Some potential responses/strategies:

(A) If you want to do it properly, pay up and do it properly: remove the entire existing roof structure, rebuild the whole thing (including pitched elements) with insulation on the outside, and mitigate high level steel-masonry junctions (eg thermal breaks at junctions) or eliminate high-level steel-masonry junctions (eg by bringing load down to floor level). Then, ideally externally insulate lower walls and ensure a continuous layer.

(B) Go for an insulation-inside strategy; and accept that there's a compromise in doing flat roof elements this way. Pay maximum attention to creating a reliable VCL throughout. Eliminate floor-level steel-masonry junctions at external walls, or accept them and mitigate as best as possible.

(C) Some kind of compromise, with transitions between outside-of-structure and inside-of-structure insulation at multiple points, detailed as well as possible.


Strategy A is often beyond the budget. Strategy B feels like a "least bad" approach. I don't like the fiddly-ness of strategy C, but is it, in the end and pragmatically, just what has to happen in many cases?


Any thoughts appreciated!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16803 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16803 Mon, 16 Nov 2020 16:49:00 +0000 ajdunlop I want to insulate the eaves for clean dry storage and am installing a central Mechanical Extract Ventilation unit and ducting that I want to keep within the building’s insulation envelope.
My house has a slate roof (original 1920s) with no felt. Rafters are 75mm.
There is some insulation between the joists so I was going to leave that in place as I don’t want all the heat from the 1st floor to end up in the eaves.

I have been reading up and have more or less decided to not bother insulating between the rafters as leaving an appropriate gap below the slates would only allow for 25mm between. Instead I was thinking of just attaching PIR under the rafters, probably 200mm to get good a u-value (~0.11 W/m2K I think) and to eliminate overheating in summer. I would tape the joins and foam where the PIR butts up to purlins and walls to get good airtightness.

I would prefer natural insulation but as far as I can see I would need a membrane above (to stop moisture getting into it and reducing performance) and below (to stop mosture from inside causing problems and for airtightness) and it would need to be very thick.

Does my reasoning sound ok so far?
Assuming it does I have a couple of questions.

Where the rafters meet the exterior wall’s inner leaf (external walls are unfilled cavity with sandstone outer and red brick inner) they rest on some wood on top of the brick. For most of the length of the wall there is some brick filling the gap between the rafters up to the slate. I worry that with my insulation under the rafters that any water ingress will run down the back of the insulation to these brick between the rafters and have nowhere to go. Therefore I was thinking of removing these to allow water to run into the cavity instead. Is this a good or silly idea?

I don’t mind having the silver surface of the PIR boards being the ceiling finish so I was thinking I should just screw the boards directly to the rafters. Although I have seen others describe using battens screwed through to the rafters being better. Is this assuming overbording and therefore doesn’t apply for me or are there other advantages?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16809 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16809 Thu, 19 Nov 2020 17:26:13 +0000 Nick Parsons

Thanks!

Nick]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16797 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16797 Fri, 13 Nov 2020 13:19:25 +0000 geuben
I've been lurking for a while whilst researching but now have more unanswered questions than I did at the beginning. I'm hoping some of you can provide answers or at least point me in the right direction.

We bought a 1890s stone (grit/sandstone?) end terrace earlier this year. As part of wanting to redecorate I've managed to convince my partner that adding IWI to the lounge would be a good idea (no cavity and in a conservation area so IWI only real option).

Having gotten over that hurdle I find myself in a minefield of trying to figure out what is the right product/technology to use and who to get to do the work.

interstitial condensation, vapour permeability, breathability etc all seem like valid things that need considering but seem far from straightforward to determine the "right" answer.
EPS, XPS, phenolic foam, Aerogel, wood fibre? So many options!
How do you tie the IWI into the insulation under the suspended timber floor?
What about ceilings and then rooms on upper floors in the future?
How do you find someone to do this kind of work and know that they'll do a good job?

I really don't want to get something done that causes problems 5, 10, 15 years down the line.

The main driver for me is to burn less gas and have a comfortable house. The payback period/ROI is less important; provided I can actually afford it in the beginning.

Sorry for the waffle, brain is a mess trying to work this out.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16795 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16795 Fri, 13 Nov 2020 08:00:39 +0000 Charenteman
Charenteman in France here.
I have been busying myself during the respective lockdowns in framing and insulating barn roofs and walls in readiness for 1st fix plumbing and electric works prior to plaster boarding the lot.

During this time I have been trying to firm up a heating and hot water scheme using a heat pump solution.
Earlier thread discussions had suggested that integrating pv panels would be a good idea - connected straight into the Hot Water Cylinder with any excess electricity (when HW is at desired temperature) stored in back up batteries to power the heat pump?).
The trouble is that when I explain this objective to local plumbers I get glazed looks. They all propose heat pump packs (Hitachi, De Dietrich, Mitsubishi) with outdoor unit and indoor unit (with HW storage) serving both central heating and hot water demands from a single tall unit.
Connecting PV panels is not an option they say.
Can anyone out there set me straight on this and suggest some tried and tested component combinations that I could refer them to?
Any help appreciated!

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16800 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16800 Sun, 15 Nov 2020 15:05:23 +0000 tony
Stitching up BC sign off

I have never heard nonsense like it, presume computer programme with wrongly input?

Anyone seen problems in the summer?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16801 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16801 Sun, 15 Nov 2020 17:41:47 +0000 Lehobbit
We have bought an old granite house to completely renovate high on the Plateau Millevaches in Limousin, Central France. The house is built into the wooded hillside so at the front there are two storeys but at the rear the second floor is at ground level. There is a flat terraced area behind the house which is just well drained earth/grass.

There are a couple of major issues we need to address. As I mentioned the house is of granite construction with solid walls of about 600mm thick. The whole of the kitchen/lounge and adjoining stable has the rear wall below ground level. For years there has been no guttering on the roof so especially at the rear rainwater has been concentrated. The walls on the exterior have also been partially rendered with hard cement as a splash back and then with horrible cement ribbon pointing or just smeared cement pointing. We obviously need to remove ALL of this and repoint with breathable lime and sand mix to let the walls BREATHE!!

What we need suggestions and advice on is a.) what tools can we use to remove the cement render and pointing. (It is stubbornly hard) and secondly what can we do to solve the damp in the rear wall of the house?

We are planning a new roof with zinc guttering and full drainage away from the house. Should we excavate behind the house and install a honeycombed membrane against the rear wall right down to floor level on the first floor and then refill with gravel?

On the inside at present in the kitchen lounge area has a secondary stone wall (on ground floor level only) which has been added at some point as the beams had rotted out in the original wall sockets!! Not sure why they didn’t replace the beams instead? This wall is about 500mm thick!! We plan to remove it as all new beams will be going in and fixed to a wall plate which will be fixed to the original wall. This secondary wall has signs of damp in it and crystallisation ( effervescence). There is about a 50mm gap between these walls.

In the adjoining stable the rear wall is original but it feels damp to the touch and the joints ( possibly old lime) are quite wet and crumbly?

We need to insulate and stop the damp coming in? We could build a new secondary wall with an air gap but were hoping to use hemp lime or a hemp block wall? Obviously we need to limit damp penetration which is tricky as the wall is below ground? Is external excavation our only option?

Interested to hear suggestions? I feel we have taken on a huge project!!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16792 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16792 Thu, 12 Nov 2020 11:13:06 +0000 lineweight
Any guidance on roughly what kind of cost to expect, and/or how to estimate it?

Is it that much related to the wall area covered or is there a per-job setup cost that means that the area of wall doesn't have such a big impact on the overall cost?

And finally does the thickness of the insulation have a big effect on cost?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16748 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16748 Thu, 08 Oct 2020 21:11:19 +0100 Victorianeco http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16789 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16789 Tue, 10 Nov 2020 17:00:25 +0000 Tom Holland Many thanks for reading this,
Tom:cheer:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16763 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16763 Tue, 20 Oct 2020 17:08:36 +0100 bardo
Welcome advice on what to go for and how much I'll expect to pay for a decent product. Thanks in advance.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16769 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16769 Mon, 26 Oct 2020 11:45:24 +0000 Dominic Cooney
The walls divide off from the main living area the downstairs toilet & shower (wetroom), as well as another room which is the Utility/plant room housing GSHP & Hot water Tank, MVHR unit, washing machine, UFH manifold, and a utility room sink.

We have built them in block to add some more thermal mass inside the insulation layer, thought it would be better for the shower cubicle/wetroom tiling, better for fixing some of the kit/pipework in the utility, and to provide a bit of added support to the staircase.

Transmission of noise is probably the main consideration (but I don't want go to the lengths of resilient bars).

These internal blockwork walls could be plaster-boarded and skimmed, or sand & cement plastered, or any other suggestions? I could also do a different finish on each side, e.g. wet plaster inside the shower room, P/B on the hallway and stairwell face.

The external walls of the barn are all IWI insulated with 100mm PIR and so will be plaster-boarded and skimmed, so if we were to P/B these as well all the skimming could be done at the same time.
I'm not sure if soundproof plasterboard would help much in this situation?

Any thoughts?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16110 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16110 Mon, 29 Apr 2019 08:23:04 +0100 ajdunlop
My house is a 1930s end terrace with double skin wall. Outer York stone, inner red brick.

The Cellar at the front of house may eventually be tanked and made habitable but the back of the cellar will remain cold and so insulation is needed to keep heat in the rooms above.The rooms above have been internally insulated with phenolic foam insulated plasterboard on a Gyplyner metal frame system with 40mm cavity behind.

I will be insulating from bellow as our floorboards are exposed and won’t be coming up. I have plenty of room (part proper usable cellar other part mostly dug out) so there are no problems with access.

There are air bricks allowing ventilation of the space and I would make sure to channel these bellow the insulation if required.

Airtightness is a big concern. I want to cut out draughts but also I have a long term aim to make the house as airtight as possible to maybe install MVHR or at least centralised MEV with controlled air inflow.

At the minute I am thinking I would avoid solid insulation and stick to wool / mineral wool insulation as it allows the floor to breath better and can take movement in the floor without later degradation of insulation and airtightness.

Ideally if I was lifting the floorboards I would put down an airtight membrane above the joists then insulate between the joists with wool / mineral wool insulation. Then I would put a layer of insulation across the underside of the joists and use a vapour open membrane under this to allow moisture to escape from the joists and insulation into the ventilated space below…
However:
* I can’t put the airtight membrane above the joists as I am not going to lift the floorboards - Can I run the airtight membrane attached to the bottom of the floorboards and around each joist? The Joists themselves would now be on the warm room side of the membrane but if I am insulating under the joists as well as between would avoid condensation issues?. I have most of a roll of Pro Clima Intello Plus that I could use.
* I will need to plasterboard the cellar ceiling to meet regulations around fire resistance as the cellar is in use. Would this not render the vapour open membrane under the insulation useless?
* The Damp Proof Course on the external walls are just below where the joist ends go into the wall. If I am trying to improve the airtightness around the joist ends and one method is a Parging Coat on the wall around them. However would I be in danger of bridging across the DPC if I do this? Any suggestions to alternatives?
** One possible solution that I have wondered about would be to have the insulation stop short of the outer wall and run the membrane up the side of this to under the floor. This would leave a gap in the insulation at the wall but the room above has insulation that has a 40mm cavity behind it anyway so there shouldn’t be a cold bridge. This would prevent problems with interfering with the DPC and could have the added benefit of allowing the joist ends to be ventilated reducing the condensation risk.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16764 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16764 Wed, 21 Oct 2020 15:07:39 +0100 dazdread
I am looking to see what interventions I need to make on my 1900 end of terrace to uprate its thermal performance with a view to getting off gas onto a low carbon renewable heating source.

I have been looking and cannot find any online and I have also checked with the Cheese project and CEE to no avail. I am based in south Leicestershire in the East Midlands and if anyone knows of a local assessor or database of assessors that would be great.

Many thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14369 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14369 Mon, 04 Jul 2016 16:44:04 +0100 Victorianeco
Should I upgrade these to 28mm units and just foam them in? Or i sit pointless given the rest of the window construction?

Failing that, anyone have a rough idea on cost to renew the whole shop front?

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16745 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16745 Mon, 05 Oct 2020 23:22:40 +0100 graham_cbruk
I have a conundrum... we're installing a Geocell/limecrete floor with underfloor heating. I'm planning on laying engineered wood flooring but have found conflicting advice with regard to the best approach to installing it.

Some experts say you should lay the wood on treated battens with an air gap, whilst others say it's fine to float the wood on a breathable underlay. The downside of the batten approach is that the air will diminish the transfer of heat from the UFH, whilst the (possible) downside of the floating approach is that the floorboards will be damaged, over time, by moisture coming up through the breathable limecrete floor. However as the Geocell, is non-capillary, it's also possible that this will manage the moisture effectively below the UFH and leave the limecrete dry.

Has anyone else had to deal with this conundrum - and if so what solution did you settle on? I'm particularly interested in the experiences of people that have had engineered wood floors down over limecrete for some years and so have real world experience of the outcomes over a decent period of time!

Thanks in advance for any thoughts.

Graham]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16740 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16740 Sun, 04 Oct 2020 13:09:15 +0100 Victorianeco
The claim is 'storm damage' but it is clear it is simply penetrating damp from poor external pointing being stone wall construction. The gable has now been pointed externally. We have hacked off all the internal plasterwork and render (1" thick) to the side of the chimney wall and found the mortar to have ~13% MC by Tony's favoured weighing method

Desiccant dehumidifier currently in-situ. Should be dry this week.

What is the best method of building up the internal render?

Dot and dab?
Lime render? If so, what mix?
Sand and cement render with water-proofer?

What is the best plaster? Standard thistle multi-finish?

This is insurance work and as much as I'd like to be green in principle with IWI or similar the job needs doing. My usual plasterer has said to just use standard sand/cement with a waterproofing agent then skim as normal.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16747 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16747 Tue, 06 Oct 2020 16:20:23 +0100 Davycrocket
I'm thinking of tackling the internal side of a rubble filled wall that's approximately 6m x 2.4m



I have 4 questions that I'd like to ask which are holding me back from making a start on the project, Thank you in advance.

1, Can a total novice to lime get a good finished result ?

( I have plastered on to plasterboard in the past to a reasonable standard)

2, Would i be best using timber battens, spaced, say 4 feet wide to aid levelling and obviously reduce the relative magnitude of the job ? (Would I leave the battens in or do you remove in an alternate order, ie finish 2 non adjoining sections ( 1 & 3 ) then fill in even number (2)section ? )

3, Is wood wool a good insulator in this case and has anybody any experience of using it on this style of wall ?

4, Other than the wood wool, what materials should I be purchase, Ie What type of lime etc.

Thanks for reading.

Dave]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16737 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16737 Mon, 28 Sep 2020 21:03:11 +0100 Den
I am trying to work out what approaches for insulation might work best and wondered whether the following 'hybrid' insulation strategy for the the roof might work:

50mm+ ventilation gap to slates/sarking
100mm flex woodfibre between rafters
breathable membrane under rafters
50mm celotex under rafters (apart from woodfibre perimeter to avoid impermeable insulation touching wall)
plasterboard

All 4 walls have no internal insulation and are limewashed rubble.

I would also plan to create a small curved coombe ceiling to maintain an air gap at the apex between both sides of the roof. Depending on the exact structure of the roof covering I could also add additonal conservation vent slates assuming LA happy with this but that will depend what's under the slates as to whether its necessary. Additonal ventilation provided in the warm space wil be via 2 new velux windows.

Does this construction look ok?. I'm trying to get a good balance between cost and performance but happy for any comments!
Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16705 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16705 Tue, 08 Sep 2020 12:29:33 +0100 Thorvaia
what are peoples thoughts?

thanks :D]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16670 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16670 Thu, 30 Jul 2020 12:19:29 +0100 PortugalProject
Not sure where would be best as way of a Hi and introduction so I gambled on here (happy for it to be moved if needed)

Anyway, I’m a long term fan of forums having restored cars, motorcycles, renovated properties etc over the years.

The new project requires some “out of the box” thinking and looking around many of the forums it’s people quoting building regs or abusing people for not paying experts to do it for them haha...... here seems much friendlier and helpful although I know it’s not so active, so I genuinely hope others here will not only help me but also get some enjoyment out of throwing around ideas.

The project is very unique, a 400-700 yr old house (originally 2 dwellings), built against the 2000yr old city wall.
You’d think this would make it an impossible project with volumes of restrictions and lots of zeros in the costings..... thankfully not here in Portugal. There are of course some restrictions but not too many, hopefully here will be a place to hear possible solutions.

The house itself is a long thin irregular building approx 2.7m (increasing to 3.5m) x 17.5m, 2 storeys.
Originally it would of been 2 houses, each with the ground floor for animals and the upper floor for living.

Good news...
a blank canvas
Very little building regs
A fun project

Bad news...
One of the long walls is the historical wall and does have some restrictions
With the above factor suitably insulating the property or even heating is questionable
Highly unlikely to have much in the way of foundations
The opposing long wall is leaning significantly
Portugal famously suffers from sever damp issues
The lack of regs in Portugal means that everything that’s been done in the past is a joke, so literally everything needs to be redone
The other walls are of an old traditional method that involved packing any old stone or brick along with dirt (yes genuinely dirt!) 50cm thick, no damp proofing etc, with a tradional lime render.

Intention...
I’m planning to convert the house into 4 small Airbnb/holiday rentals with an overall medieval/historical theme.

I’ve lots of questions, queries and desperate pleas for help but thought the above would help paint an initial picture.

Thanks in advance and Hello again to everyone!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16686 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16686 Mon, 10 Aug 2020 21:16:47 +0100 jamesingram Seems like an opportunity to encourage some 'fabric first' energy efficiency improvements to housing
(England only)
some info here
https://www.gov.uk/government/news/quality-assurance-at-heart-of-new-2-billion-green-homes-grants

and

https://www.thisismoney.co.uk/money/bills/article-8595921/Thousands-eligible-Green-Homes-Grant-scheme-qualify.html]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16594 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16594 Mon, 08 Jun 2020 13:58:21 +0100 wholaa Are there risks attached? Is expanded glass beads better?

___]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16641 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16641 Mon, 06 Jul 2020 11:55:53 +0100 tony
Advice on how to get this past building regs and the inspector. Last time it was nearly impossible, this time I have a feeling that it will be impossible.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16587 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16587 Thu, 04 Jun 2020 07:48:55 +0100 rosecottage
I am at the junction where I need to think about applying my internal plaster. This will be lime based to keep the house as breathable as possible.

Originally I was keen on attempting this myself. Then after I patched some render I went off the idea as it was not something I enjoyed (under the gable etc.).

However after recieving plaster quotes in excess of 120 per M2, we actually can't afford a professional lime plasterer as the cost would be half our budget!!

So I am now full circle again and wondering how easy it is to internal plaster with a lime product? There are many products out there and will need to decide which one. The house is an old cottage but has mostly flat walls (hopefully easier) and I don't mind if these end up a little wavy as you know what the say; it adds character!

It will be going on a mixture of bare masonry, wood wool board and wood fibre board. Thank you]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16642 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16642 Mon, 06 Jul 2020 12:22:31 +0100 Michael1 Regards
Michael]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16251 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16251 Fri, 20 Sep 2019 12:25:40 +0100 modernvictorian http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16656 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16656 Mon, 13 Jul 2020 09:55:31 +0100 thebeacon
i’m looking for some advice regarding installing loft insulation in a victorian house.

I am renovating a victorian terrace house, i have already raised the ground floor floorboards, laid rock wool insulation between the joists in netting and a vapour proof membrane then laid a new wooden floor. I am ensuring everything is breathable where possible.

I’m now looking to insulate and board over the loft. The current plan is to insulate between the existing joists, lay a new set of joists going in a perpendicular direction and insulate between them, then board over the joists so the space can be used as for storage.

The current joists are 70mm and we are considering putting in 100mm joists to board over. We are having someone come in and do this job for me, they said to have a 20mm gap between the top of the insulation and bottom of the board to allow for air circulation. This would then allow for 150mm of insulation. I have a lot of rock mineral wool left over from the floor that i want to use. its 100mm in depth (https://www.knaufinsulation.co.uk/products/rock-mineral-wool/earthwool-building-slab-rs45)

Breakdown:

floor boarding
100mm joist with 80mm rock wool insulation between an d 20mm gap for air circulation
70mm Joist with rock wool insulation between
Ceiling


Is there any think else i should be considering with regard to best practice for doing this?


Thanks,]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16628 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16628 Mon, 29 Jun 2020 13:08:13 +0100 LoftDIY87
Want to fit 12mm Hardiebacker board in the shower area and 12.5mm moisture plasterboard on the rest of the walls, then tile.

Just called Hardiebacker and they said their boards should only be fitted direct to the studs, NOT have any insulation in between (even if only 15mm)? As they can't guarantee it'll hold the weight?

How can this be dealt with? Would the same issue not arise when plasterboarding over the 15mm insulation and tiling on top?

I would have thought long screws were the answer but now am a bit confused on which direction to go, any guidance?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16653 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16653 Fri, 10 Jul 2020 12:14:59 +0100 Michael1 Regards
Michael.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16626 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16626 Sun, 28 Jun 2020 10:28:03 +0100 rosecottage
I would like to install a Limecrete floor through the current building - as an old building with no damp coursing, common sense tells me a solid slab will just push any damp out and up the walls giving me much bother in the future.

This will also take UFH. What I really wanted was a concrete like floor finish. Has anyone done similar with Lime; any issues with staining or dusting?

Thank you]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16644 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16644 Tue, 07 Jul 2020 16:03:22 +0100 Victorianeco
We've been asked to change a felt roof and upgrade to meet building regs. No idea if any insulation is present until it's ripped off.

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16636 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16636 Sat, 04 Jul 2020 17:45:06 +0100 beadlesabout
We've taken on a renovation recently. Curiously, it was originally a single story stone (rubble filled) cottage that was later extended upwards to 2 storeys with single skin brick in 1911. The brick extension was done functionally rather than beautifully so it was always intended to be rendered.

Today we find it with several layers of render. Varying in type, with dash in places, thick cement render, Tyrolean, the works!

We think we have 3 options:

1) Hack it all off and re-render with a breathable render. Either a modern breathable system, e.g. silicone or traditional lime based render.

2) Hack it all off and install EWI and render over the top with a breathable render.

3) Don't hack it off and affix EWI on top of existing render and top with a breathable render.

Here are some images that show the layers of render and the condition of the walls - https://imgur.com/a/Wj6bhNM . We assume it's important that being a stone wall it needs to breathe, so therefore, option 3 would mean locking moisture in under the existing render. Or is that not a problem? Where we have removed render on one side of the house, we did find the mortar in the stone work was wet, loose and missing in places. In one area, so bad that the outer leaf is bowing and we think we need to rebuild in blockwork. We think the rest of the house is sound though as that was the wall that faced the elements and moisture had got behind the render there.

So, to EWI or not to EWI and to hack off or not to hack off, that is the question?

Thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16637 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16637 Sun, 05 Jul 2020 11:08:34 +0100 wholaa
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16594&page=1#Item_0

The same property is drywall with steel studs in most walls, except for a few international partition walls that use wood studs. I notice on several walls, mainly the wall to neighbours, that the steed studs are very visible with a thermal camera in cold weather. This is less apparent on other walls, even though they are far more exposed and a highly wind exposed position. Is it typical for steel studwork to show up on block built structures]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16627 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16627 Sun, 28 Jun 2020 17:16:16 +0100 atomicbisf
I'm looking for some advice on installing cladding over EPS insulation.

My sister has had a small extension built on on her park home. At the moment it is finished in plywood (untreated). The plan is to apply 100 mm EPS EWI on the ply. I have suggested a lapped cladding may be an easier DIY solution than a silicone render.

So first of all, does the ply need a special primer before the EPS can be fixed with adhesive and plastic "mushroom" type fixings?

Second, would you foam the boards together at the edges? That's what I've done with EPS insulation in my loft and its very easy, or is there a better way?

Third, how would you attach the cladding strips? Would it be sufficient to screw straight through the cladding and EPS into the ply, or would vertical battens be needed?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16611 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16611 Tue, 16 Jun 2020 09:15:10 +0100 Sprocket
Initial calculations on the planned new roof suggest a condensation risk.
I am wondering about the best way to avoid this and how "safe" I need to be.

We will have, from top to bottom

a torch-on 2-layer membrane
100mm of Foamglas Readyblock (λ 0.036)
9mm ply
200mm roof joists with additional insulation between
12mm plasterboard

Taking as an example 22 C inside at 60% gives a dew point of about 6 degrees.

My original spec put as much sheep wool (λ 0.035) in as I could get... ie. 180mm ish of sheep-wool insulation between joists. This gets me an overall average U for the roof of 0.13 (0.12 between and 0.22 at joists) BUT this insulates well enough to put the lower surface of the ply between joists at 6.2 C. At -5 outside this falls to 5.1 C below the ply.

Adding a VCL on the warm side would be tricky and feels wrong. It would create a sealed airspace. And anyway we have quite a few downlights (thought they are pretty airtight) to fit into the plasterboard.

So presumably the sensible solution is just to use less insulation between the rafters? Just decreasing to 100mm fleece seems to give U=0.17 (average for 0.16 and 0.22) and raises the temperature below the ply to 7.4 at -5 outside (or 9.6 at -1 outside).

My questions:-

Is reducing the insulation (never thought I would say that in here) between joists the way to go?

Does the simple numerical approach really sensibly represent what happens with sheep-wool insulation given that it probably allows a little air movement and it has humidity stabilising properties? Does sheep-wool give me some sort of extra leeway?

What sort of temperatures in and out should we really be considering for these dew-point calculations? Do we need to consider rare extremes or are averages enough given that the building will smooth things out a bit? Is my 7.4 degrees C below the ply a safe enough margin when the dew point is 6?

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16608 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16608 Mon, 15 Jun 2020 09:04:39 +0100 WeeBeastie
They do have a point as the building is quite monolithic in appearance with no natural divide such as a downpipe at the boundary. They don't want EWI on their half of the building.

Of course I could press on regardless, assuming the Council gives permission, but I'd like to consider alternatives. I do know that anything other than full EWI is a compromise but I also like to avoid conflict!

The walls are 9 inch brick with painted harling on the outside and lath and plaster on the inside. I have problems with condensation and mould.

I'm wondering whether the front and rear walls which adjoin the neighbour could be left alone externally and EWI added only to the side wall (east). Then IWI used on the front (N) and rear (S) walls. There would be very little IWI needed on the south wall as a new extension would deal with part of it, a large window another chunk, leaving only around 800mm adjoining the neighbour to deal with. The N would be more extensive.

Would this be a sensible compromise? I understand from what I've read that IWI walls should be modestly insulated - u value no smaller than 0.5 - to minimise risk. Would mixing this with a lower u value EWI wall be a problem? Should I consider IWI on all three walls since there will be internal disruption anyway for electrics etc?

Thanks for any advice.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16621 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16621 Sun, 21 Jun 2020 17:14:33 +0100 owlman
Currently the loft has a decent sized N. facing Velux rooflight and a small S. facing Velux rooflight which lends itself to an en-suite.
On the W. side is a large single glazed gable end triangular window, with a 4 M base at about head height. The old wood frame needs replacing and, thinking Maintainance wise I was toying with the idea of powder coated aluminium 3G. I've contacted several curtain walling companies who all say they can do it so no shortage there. Does anyone have any experience of this type of thing indeed tips on glazing, opening casements, etc?

Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16607 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16607 Sun, 14 Jun 2020 13:56:00 +0100 Doubting_Thomas
Of course there are exceptions to all of these, I’m just looking for general collective wisdom

So far I got:

Orientation/form:
South facing roof slope
Minimal North glazing
Compact form factor

Walls:
Ideally rendered or clap-boarded (so it can be externally insulated)
Else, large cavity for bead-fill insulation

Avoid:
Conservation area (!)
Overshadowed garden
Steep slope/retaining walls
Running water
Crawl Space
Timber suspended floor?

Any others?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16573 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16573 Mon, 25 May 2020 12:03:12 +0100 Hiceadha
The house I recently bought to fix up is a small 2-storey mid terrace house, built around 1900-1920 I would guess.
I am considering internal insulation. The existing walls are 600mm solid masonry walls with lime plaster on the inside. The existing floor appears to be poured cement throughout although in one room where I have pulled the carpet there are sheets of plywood laid, I'm not sure what this is for.
In order to make the house cheaper to heat, my initial thoughts were to fix 40mm wood fibre insulation direct to the front and back walls of the house internally, covered with lime plaster again. This would provide a better U value overall and retain the walls permeability. The side walls are shared with occupied buildings so these wont be required.
The attic will be filled between the rafters with regular fiberglass insulation, unless anyone has a suggestion of a better alternative?

The floors I was considering leaving but since I will pull up all the carpet I am considering a thin 16mm sheet of wood fibre insulation again. I don't think a vapour membrane would be needed here either to help prevent rising damp, I would imagine there is a pre-existing one below the floor.

The external wall of the bathroom houses the shower also, I'm guessing I can't use the wood fibre here without some sort of vapour barrier behind the tiles.

I can take the floorboards up on the first floor and fix wood fibre insulation to the external walls between the joists too, although I probably can't avoid the thermal bridge through the timbers themselves and through the concrete lip the joists sit on. I was wondering then should I take down a strip of the drylined ceiling from the ground floor as I am running cables, then replace it with a breathable material sheet and lime plaster the ceiling here. This will allow the ceiling void to be breathable and hopefully prevent any damp on the joists.

For ventilation I will add an extract fan to the bathroom and kitchen. The windows are single glazed, I am thinking of drilling a few holes along the top side and adding trickle vent covers. This should provide enough ventilation to help prevent any damp.

Any advice would be appreciated as the house is completely damp free, not any bit of evidence of rising damp anywhere even though it has not been occupied for at least 5 years. I am very cautious of messing with the houses "environment" given that their is no issues with damp, but don't want to cause any issues now with my intentions to reduce the gas bill.

https://imgur.com/2h5NxCl
https://imgur.com/PR2P8ZP
https://imgur.com/SQgKDJG
https://imgur.com/3Bq3sLA
https://imgur.com/VusJHIR]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16569 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16569 Fri, 22 May 2020 17:19:38 +0100 WeeBeastie
Looking to use cork boards. Not DIY!

Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16551 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16551 Fri, 15 May 2020 14:34:11 +0100 LoftDIY87
However I'm not sure if I need a vapour barrier on the stud walls? The exterior walls are tiled with OSB (except for gable wall, which is rendered OSB). There is 90mm Celotex insulation in between the studs and I will be putting 12.5mm plasterboard over this, which will be skimmed and painted.

Should I staple a vapour barrier to the studs before I plasterboard, or is it overkill?

Or should I at least foil tape the insulation joins and create a vapour barrier that way?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16545 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16545 Mon, 11 May 2020 11:33:23 +0100 ag1
We have taken on a 19C random stone rubble end-terrace in Devon in need of deep refurbishment. 600mm rubble filled walls, no central heating, off gas network, concrete floors, cement external render, south east facing. It is 66m2 and we are planning a replacement 40-50m2 extension (see sketchup pic of proposal).

We are renovating the main house first before undertaking the replacement extension. So far we have stripped hard plaster, installed 5kW wood burner in the living room, installed 30mm expanded cork IWI to living room using lime (not enough room for more unfortunately).

We are looking to install cork flooring on ground floor to avoid replacing the floors, installing double glazed casements, moving bathroom from extension to ground floor and as we have to cut into the slab for drainage replace a small portion with insulated ufh. The extension will be dual pitched, timber frame, insulated as much as poss, would suit ufh and has capacity for 7/8 SE facing panels on the roof (PV or ST). The bathroom will be happening in the next few months so DHW will need to be installed soon and I think we'd struggle to fit a thermal store in the main house.

We are stuck choosing a DHW and CH system, we've whittled it down to two options we'd really appreciate some advice on:

Cheap and simple option: immersion unvented cylinder for DHW boosted by PV or ST on extension roof when it happens. Woodburner centrally in extension. Electric on demand ufh in extension (maybe 30m2 so 3kW@100w/m2) and radiators upstairs in main house. We can store wood and we like the aura of a burner, but running two burners could become tiresome when their charm wears off and then relying on elec can be expensive and inefficient. We can install the ufh under deep screed so it works as a thermal store and can work during the day with PV although we might be asking a bit much of 7/8 panels (there's a future gara/shed we could put maybe 3 on). E7 could help keep costs down, but I need to do more maths.

Expensive option: unvented cylinder for DHW boosted by PV. ASHP and second cylinder running wet ufh heating in extension and extended to large rads in main house. We can probably find a spot for the unit, but I fear it will be expensive and not as efficient as promoted, as well as having ongoing maintenance costs. The cost of ASHP and PV does erode the budget somewhat drastically and while the house should do us for a long while, we'll likely want to move at some point.

That's where we've got to with our thinking.

Any thoughts or ideas from the community would be greatly appreciated as we try to navigate this minefield.

Cheers]]>