Tue, 19 Dec 2023 06:29:47 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14992 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14992 Sat, 18 Mar 2017 22:10:51 +0000 Tullich
In timber frame wall construction 80% of the insulation should be outside of any airtightness layer, and 20% inside.

How strictly is this rule usually followed, and with what results?

Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14979 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14979 Mon, 13 Mar 2017 21:43:50 +0000 Tullich
A quick first post to say hello.

I'm shortly to undertake a timber framed self build in the Highlands, and have been reading posts here for a while now.

I've finally got round to registering, and look forward to hearing your advice and suggestions.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14966 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14966 Wed, 08 Mar 2017 19:33:00 +0000 ward32 This was a full plans application and after some further information about window and door reveals and wall condensation risk assessments (solid wall + EWI) I got their approval. No question about the roof so I assumed that was all fine.

The roof was designed by a S.E but he did not specify the coverings and insulation. My build document to BC stated:
22mm Uditop sarking
200mm Omnifit Stud between rafters (200mm rafters)
70mm PIR to the underside of the rafters
VCL under PIR
Plasterboard under VCL.

Inspection was before VCL and plasterboard and went something like this:

BC said the construction didn’t match the (my) specification and because I hadn’t read it just before he arrived I just accepted this – first mistake.

BC: there will be a huge condensation risk of the wool sweating behind the sarking.

ME: there’s a VCL on the inside and the sarking is vapor permeable so where is the moisture going to come from?

BC: there should be a ventilated air space between the wool and sarking boards. There’s too much insulation! (this was clarified later in the context of “a ventilated air space roof” – 4 days later).

ME: there isn’t an air space! I have constructed it to the sarking board manufacturers recommendations

BC: I will need to see the manufacturers data sheet.

End of visit.

Emailed Uditop sarking board data sheets, the full plans build specification (which they had from day one) and a condensation risk analysis for the roof build-up.

Phone conversation with BC officer a couple of days later went something like this:

While BC was going through my build specification he was struggling to understand the written spec’. I explained the make-up of the roof and how it was as the manufacturers data sheet, and exactly as I had constructed it. [to be fair I didn’t draw the roof make-up and the written description was out of sequence, hence the confusion].

BC then looked at the manufacturers data sheet and immediately focused on a table talking about board thickness and maximum rafter spacing and said I was using more than 100mm of insulation. The table actually meant I could use 22mm boards up to a maximum rafter span of 850mm while 100mm boards could have a max spacing of 850mm! [I'm losing confidence!]

BC then moved to the construction examples in the data sheet and asked if I had used their proprietary insulation and I said no (I was tempted to say yes for an easier life because I knew what would follow). He also pointed out that the data sheet did not show PIR boards under the wool insulation

BC said he couldn't accept this because I have used a hybrid system that is different to the manufacturers data sheet. [manufacturers data sheet show their own insulation products but I had used omnifit as it's bit better insulator but has a similar vapour permeability. I had also included extra insulation below rafters which is not shown on the data sheet - I'm going down!!]

[I wanted to say they had the full plans 18 months ago so why wasn’t this questioned before I built it– but I held my tongue]

And finally…

I directed him to my condensation risk analysis and after I had talked through the numbers he was happy – to a degree.

BC said he would put copies in the folder and sign it off.

And finally I get an approval email:
I am willing to accept the details but must inform you that any defects likely to be caused by interstitial condensation in the future, will be at your own risk.

Any advice for the future?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14922 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14922 Sun, 19 Feb 2017 12:35:09 +0000 Triassic
What options do I have for insulating the cold junction between the top of the foundation wall and the sole plate of the timber frame?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12788 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12788 Thu, 13 Nov 2014 22:24:44 +0000 ward32
I created materials that match what I am using: Brick outer wall, Turbo blocks under floor U=0.11, EPS segment under floor U=0.034, Concrete beams with EPS infill U=0.034 and blown EPS U=0.34
Boundary conditions are external wall = 10degC, Internal wall = 20degC and under floor = -10degC.

Do the temperatures on the isotherm lines show real temperatures?
I expected to see the internal wall and floor surface to be close to the start boundary condition of 20degC.
It does highlight that taking insulation deep in to the foundations is unnecessary!

I would appreciate any comments.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14767 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14767 Sun, 11 Dec 2016 10:38:37 +0000 Carol hunter We have posted on here alot over the years and found a treasure trove of help....here's a somewhat obscure question - not sure which is the right category.
We received pp in 2005 for 9 dwellings - so called "Eco houses". My husband and I worked hard for the PP as it was in a conservation area. The only reason we received pp was because of the nature of the building materials/energy efficiency and low impact on the natural environment.
Amongst the conditions we were required to provide " a scheme for the provision and implementation of contamination investigation and remediation.....and the works carried out in accordance with the approved plans."
There followed weeks of clearing and thousands of pounds spent on an professional contamination survey.

Here's the question. A small but very unsympathetic developer has bought the two plots next to ours on which he has pp for block houses clad in wood....! Meantome he has brought discarded stuff he can't take to the recycling centre and dumped it all over the unbuilt on plot. we know he brings trailer loads of stuff like old washing machines, office chairs last, aerosols and loads of building waste from other "developments" of his and leaves it out in all weathers in great piles.

This is one of the plots we spent much time and money on clearing of the rubbish dumped down here by the village for many years. Since it was a condition of building that we cleared the land before building do we have any grounds for the Planning Dept to enforce him to clear the land? A preliminary exploration with Planners doesn't look hopeful - They suggested writing to Environmental Health Who suggested they would only do anything if there were contaminants...Any pointers would be very much appreciated!
Thanks, Carol]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14802 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14802 Tue, 03 Jan 2017 15:31:11 +0000 discotroll
As our planning application drags it's feet slowly towards conclusion we have a slight dilema regarding removal of old trees/plants and the planting of their replacements on site. The planting/ecology/biodiversity is all part of the development plan to rejuvenate a brownfield site.

We have been advised by our ecologist that we really need to plant our new hedgerow before March (so any hibernating rodents, frogs, etc) have a new home to go to when we clear the site, and the trees approved for removal also need to be gone by March so we don't get any nesting birds before things can be cut down.

All the tree removal/new planting side of things has been okayed by the local TPO officer and ecology consultant the planning office use (as part of the ongoing planning application) but are we okay to start this side of things on site without planning permission? If we sit around waiting for permission to come through I can see the trees/bushes full of nesting birds and that's the year gone before we can get stuck in to the project.

Anyone any experience of this kind of thing?

Thanks,

DT.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14781 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14781 Tue, 20 Dec 2016 10:55:52 +0000 joe90 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14699 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14699 Fri, 18 Nov 2016 10:02:31 +0000 flexon http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14709 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14709 Sun, 20 Nov 2016 12:04:05 +0000 converse
Just musing really. Any thoughts?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14693 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14693 Wed, 16 Nov 2016 13:19:51 +0000 tony
Discuss]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14683 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14683 Wed, 09 Nov 2016 11:11:20 +0000 ward32
My warm roof build up will be:
1. Concrete tiles on 50mm ventilated batten space.
2. Wood fibre sarking @22mm - vapour permeable @0.55MN.s/g
3. Omnifit stud between rafters @200mm
4. 70mm PIRfixed to inner face of rafters, taped/sealed at all joins
5. plasterboard stuck and screwed to PIR and rafters.

PIR datasheets gives vapour resistance at about 100MN.s/g and BS5250 says you should have a minimum of 250MN.s/g.

Everything above the PIR has good vapour permeability so moisture escaping up should dissipate!

Question is will a well jointed layer of PIR work as a good vapour control and airtightness layer in this situation?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14675 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14675 Fri, 04 Nov 2016 18:31:20 +0000 woodgnome If using say, a silicone type render, what happens where the render meets the aluminium door/ window frame? Can it touch,or is a bead of some sort required?
May use traditional sand/ cement/ lime, but I prefer the finish of modern renders.
Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14672 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14672 Wed, 02 Nov 2016 10:26:46 +0000 malakoffee
Plasterer 3 advised to dry-line over the Celcon blocks, to avoid the emergence of "inevitable cracks". It is true, that there are a few hairline cracks across multiple courses already. The blocks were laid two years ago.
( I thought that the cracks were partially due to inadequate curing time between their manufacture and their laying. )

Plasterer 3 will put my job in the queue and expect to do it in January.

I gradually realised that I could have a go at dry-lining with fermacell boards. i.e. save on labour and put the money into the increased cost of the Fermacell boards.

After all Fermacell boast that a DIYer can do it and make a reasonable job.

Upon reading the Fermacell info I read that - for the dot & dab method :-
" .. expect to place two mechanical fixings on each board."

methinks : I've never read about anyone placing extra mechanical fixings on plasterboard. Why for Fermacell ?

"For dot & dab . . .use tapered boards." OK but what about all the offcuts used in the door/window reveals - which will inevitably have cut edges ?

Both edging techniques therefore necessary ??]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11625 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11625 Thu, 16 Jan 2014 21:12:07 +0000 Ed Davies
North and south facing roofs, each about 18 m east/west and 8 m eaves to ridge. South roof will have PV, solar thermal and a row of Velux windows. Roof is quite steeply sloped: 60°. Underneath is timber I-beams with a, presumably, OSB sarking layer on top. That'd, also presumably, have a non-tenting membrane, counter-battens and battens on it.

Major considerations are wanting a smooth surface for rainwater harvesting and, as far as possible, DIYable for an inexperienced builder. There's the option of some outside help on a casual basis but always the possibility of logistical problems with weather windows, etc.

Up until now I've been assuming profiled steel with the thought in the back of my mind that something like Decra might be easier to self install. Just having a last-minute rethink considering the problems of largish steel sheets and also issues of flashing above Velux windows and stuff.

Looking specifically at Decra it seems quite expensive (a good few extra £1000s which I can think of better uses for) and also seems to most be stone coated.

Any cheap options which might be more wieldy and easier to flash than profiled steel?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14619 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14619 Fri, 14 Oct 2016 19:18:31 +0100 Shakyjake
I am looking into a designing and building passivhaus bungalow and I was wondering if there was anyone in Cheshire who are currently building one as we speak, or have completed it recently?

I think a cheeky ask would be :
* could I pick your brains,
* Could I come and see some of the detail - particularly if you're using Solar panels/Green roof/ASHP/GSHP, and
* learn from your experiences

Thanks in advance

Mitch]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14561 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14561 Fri, 23 Sep 2016 20:00:21 +0100 OnTheEdgeOf
It is in everyone’s interests that the UK build better quality new homes (not just more!) and for those that buy them to have better protection.

Click this link to see the petition and start sharing it:
https://petition.parliament.uk/petitions/167660

(Note: This is not a change.org petition so you won’t get lots of spam emails!)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14597 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14597 Wed, 05 Oct 2016 18:34:45 +0100 archess200 Instead, I want to put in a through wall vent, using something like a marine 'mushroom' vent, operating on a screw that turns a stainless or plastic dome. That is what I want, that is what I am sure will work, but difficult to pursuade the Building Inspector or to get an official free air area. I have emailed several vent suppliers but am now getting back statements saying that they cannot give that info. One sent pictures of them measuring the size of the object, but couldn't measure how high it was shut, and how high open.
This is going through a timber frame, so a tube through the frame - 100mm should do it - then the mushroom vent, either inside or outside. Inside, you twist the dome, if outside you operate via a screw thread. With the dome inside I would put a grill with fly mesh outside. This still leaves a 100mm dia. cold bridge: not good news.

Having trouble sourcing a good external grill that offers adequate 5000 sq.mm. of open area, and also satisfying myself that the mushroom vent itself would give this amount. I think that a circle of 100 dia. would give 314mm circumferance, which means it has to open only 16mm to provide 5000 sq.mm.
Am I right?

Any comments, suggestions as to sources or ideal options?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14547 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14547 Mon, 19 Sep 2016 17:21:11 +0100 ealingbadger
The slab for this is 8m x 6.5m, so it's a bit more than your typical garden shed.

The problem is that I am struggling to establish a suitable fastener to use with the ties. Simpson only recommend a single (and naturally particularly expensive) type of galvanised screw of their own brand (designated the SD10112) and for which I cannot find a UK stockist. (They are available on eBay for around £128 + carriage for 500 but as I am going to need nigh on 2,000 I don't fancy paying this if I can avoid it.)

A conversation with Simpson UK this morning in an attempt to clarify what other fasteners might be suitable has, sadly, left me none the wiser as they (quite typically) are disinclined to offer anything but the very vaguest of possible alternatives.

They did say that I might consider a good quality German screw (Spax for example) as an alternative as the sheer strength of the cheepy screws typically available are distinctly below par but since I was already aware of this it did not help much.

Goggling around has not helped much except to highlight the fact that there are plenty of suppliers of the ties but no suppliers of the recommended screws.

So the question is, assuming that people are not just buying the ties to make into wind chimes or other garden ornaments - which screw are all the purchasers of the ties buying to fix them to their timber and therefore, by extension, fix their building to the slab sufficiently well to avoid it being blown away on a light zephyr?

The recommend screw is billed as a hot dip galvanised hex drive 1.5" #10 and looks more like a mini coachscrew with a good solid old fashioned dowel section to it rather than the more modern narrow necked screws.

I could just get hold of an individual tie and see which screws give me the best fit but this is a bit of a hit and miss approach and I would prefer to have a better guide than my own intuition. Nevertheless, if needs must then this is what I will have to do.

To add to the misery (and hence my nervousness about selected the correct item) the Simpson web site is full of dire warning about corrosion in connection with treated timber and is recommending only hot dip galvanised or stainless (316) fixings as being safe in this context.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10710 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10710 Sat, 25 May 2013 14:12:11 +0100 Greenfish
I am thinking that we just need to tape that junction, but with what kind of tape? Over or under the plasterboard or plaster? Does it need to be extra flexible? Going to have coving, properly fixed will help too or just hide the problem.

Or should I be covering the ceiling with a VCL under the plasterboard, plastered into the wall at the edges. I have read that suggestion here, but it seems a lot of extra work (on stilts with a 9ft ceiling). Just empty roof space above, unventilated roof, 500mm of insulation (loft roll or warmcel). Surly the taped and skimmed plasterboard and taping any penetrations will be air tight, just the edge is the issue. Do ceilings need a VCL?

Also read that not nailing too near the edge of the pbd will avoid edge cracks, but I'm not sure I would want to rely on that.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14523 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14523 Wed, 07 Sep 2016 15:43:19 +0100 numenius http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14526 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14526 Fri, 09 Sep 2016 13:59:53 +0100 RoseMill_DandR We have a gas supply but no meter in our newly converted warehouse. We can have our meter fitted by who ever we choose as our new supplier but so far I've only found the big six will fit meters not the better energy companies like Good Energy, Ovo or Better Energy. Has anyone had a gas meter fitted by anyone other than the big six?
Thank you.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14094 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14094 Thu, 03 Mar 2016 13:56:04 +0000 SeerGreenSIPS
They've come up with the solution in the attached image... and I was wondering if any 'experienced hands' out there had a view on what they are proposing

In summary, the solution involves:
* Soleplate rests on 65mm Foamglas Perinsul HL
* Which in turn, rests on our Forticrete blocks
* On the inside, there's 25mm on Celotex against the SIPS panel and soleplate, increasing to 50mm further down (next to the Foamglas and Forticrete blocks

All comments v welcome indeed. Thank you]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14504 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14504 Wed, 31 Aug 2016 12:21:32 +0100 tony
From now all social housing new builds should adopt this approach and the big develpor will follow or literally get left out in the cold.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14498 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14498 Sat, 27 Aug 2016 23:16:26 +0100 a63245347
It will have quite a lot of opening glass facing North West and also North East. These will be Bi-fold doors if we can afford it.

I'd like it to be insulated well.
It will have a warm flat roof covered with epdm.

I'm not sure what the most practical insulated wall construction would be? The outer skin is likely to have some form of shiplap weatherboard as a rain screen. Should it be a normal block cavity wall made from block? Or a solid block wall with EWI on the outside?

I think I would prefer the thermal mass to be on the outside, so that it warms and cools quickly.

Any thoughts would be much appreciated. Thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14491 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14491 Thu, 25 Aug 2016 12:06:48 +0100 ringi
What level air tightness can be got just by for example Icynene between all the wall studs with little effect make towards air tightness apart from round opening, windows, etc? E.g. can all the timber work be done by normal trade’s people, and then the “bad workmanship” sorted out by using spray insulation?

What design changed would be needed to enable this? (For example not doubling up on studs, or putting 2by2 horizontal timbers on the outside of the frame before fitting the sheathing board.)

PS are there issue with racking resistance by putting the sheathing board on horizontal timbers rather than directly on the studs?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14487 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14487 Sun, 21 Aug 2016 19:53:09 +0100 numenius
I am wondering if they are worth the price for the effect (i.e if a normal timber frame-masonry steel wall tie, (like Staifix STF-6) nailed onto our SIPs panels will *really* conduct that much heat out anyway since we will have 142mm SIPs then 100mm Kingspan on the inner wall. In one respect it seems to be such a tiny bit of cold bridging that it's not worth the bother, but then also, if you add up the hundreds used across the whole house, it may actually add up to a worthwhile number. Anyone used these or have any thoughts on the value of using them ?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14445 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14445 Wed, 03 Aug 2016 21:48:03 +0100 discotroll
I hope I'm posting in the right section and my question makes sense.

I'm working on a boat project (liveaboard) and the roof insulation set-up is, literally, giving me sleepless nights as I try to think of how to eliminate cold bridging through the timber rafters forming the 'flat' roof.

I'm familiar with the principals of 'cold' and 'warm' roof designs but unlike a double-skinned brick structure or similar, the timber rafters will, at the end of the day, be attached to the steel hull of the boat. This, in turn, will directly let the outside cold travel through to the rafters.

I would much prefer to go down the route of a warm roof but my poor brain cannot see past just insulating everything (roof and walls) from the inside like a a kind of separate 'innertube' of insulation.

I'm sure more details are required but hopefully there's enough here to get the ball rolling and let me get some sleep at night!

Thanks,

DT]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14451 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14451 Fri, 05 Aug 2016 14:00:47 +0100 Doubting_Thomas
We're looking to procure a CLT (Cross Laminated Timber) structural frame on our self-build house. I've had an independent engineer do the tender stage design and am now ready to send out for quotes.

The thing is, I'm wondering if we need to also establish a building contract with the frame provider at the same time. Since these frames come to site and are erected by their in-house team, we will essentially be asking them to build the frame on our site as well as just produce the components.

I'm sure there's an element of consumer protection in the act of purchasing, but it strikes me that we should probably have some form of written agreement for the site works. Just wondered if people on here had done something similar?

JCT Minor Works perhaps?

Thanks in advance.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14426 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14426 Thu, 28 Jul 2016 09:16:36 +0100 John Pedersen
I had a plan for a cold roof on the dormer I'm building - here isn't enough headroom for a warm roof. The original plan was to have 50mm air space above 120mm Celotex in the roof space. In haste, I went a bit off plan and fitted the rafters into joist hangers at the outside end, rather than supporting them on a beam. The way I've now installed the rafters means the ends are closed.

The building inspector pointed out my error, and my heart sank. I'd expected I'd be required to make a substantial re-build. However, he just said to make sure the vapour barrier was airtight and call it a sealed roof. I understand what he's suggesting, and I know the importance of sealing the roof really well (no lighting in the ceiling) but I imagine that even with the greatest care, there'd be an air leak somewhere, and the space would eventually become damp and there'd be no way for it to dry out. So even though I have building regs approval, I'm hesitant to go down that route.

Any suggestions that don't involve reinstalling the rafters (I've temporarily fitted OSB on top of the rafters to give me a dry workspace while I sort out walls and floors)? I can't drill holes in the supporting beam, as this would compromise its strength, and anyway wouldn't provide anything like the planned for air flow.

Thanks,

John]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14422 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14422 Wed, 27 Jul 2016 08:42:10 +0100 flexon Could anyone please advise on a suitable cost affective solution to a render board for rendering onto a batterned sips pannel.
Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14408 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14408 Mon, 18 Jul 2016 20:51:16 +0100 Stuart112 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14395 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14395 Wed, 13 Jul 2016 08:27:05 +0100 richardelliot
The answer to this question is probably be obvious, but I can't find the answer in the manual. If anyone else has this MVHR unit (or a similar one) I'd be grateful if you could set me straight!

We've just moved into our new build and turned on the MVHR unit for the first time. It sent our electricity consumption through the roof (about 24Kwh per day) and I have worked out that the in line heater was turning itself on. I've currently disabled the in line heater.

The control panel is very simple. We've got it set to "Summer Bypass Normal". I can see an "indoor" and "outdoor" temp on the control box. Is the "indoor" value effectively a pre-heat target for the in line heater? What does the "outdoor" temp do?

I've had a look in the manual but couldn't see anything useful.

Many thanks for any helpful comments,
Richard]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14385 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14385 Sun, 10 Jul 2016 00:27:28 +0100 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10612 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10612 Tue, 30 Apr 2013 18:34:06 +0100 Greenfish
Any suggestions or recommendations for outward opening ali-clad windows? All I can find so far is Rationel, any others?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14300 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14300 Fri, 27 May 2016 14:50:26 +0100 divorcingjack
I have posted about my foundation woes before on ebuild, but sadly it is no more so I'm updating here instead :)

Our site is overlaid by 1-1.7m of organic topsoil, which not only is uneconomical to get rid of (no space to lose it on the urban site) but we cannot drop the level of the house that far down, as it is surrounded by other buildings and we would lose a lot of the light into the ground floor.

So, we have the choice of mini-piles or padstones. Both would tie into a network of ground beams, which will be formed as part of our insulated slab (MBC), which will sit on top.

We have received a quote of approx 5.5k for 35 driven 4m piles, with a meterage rate below that. I'm waiting on another piling quote to see whether this one is way out.

So, what's going to be most cost effective? Piles or padstones with rising columns? The ground floor layout is 205sqm, access for a large digger if required.

The piling guy has estimated a week to complete the piles, but we have a very good digger guy.

Any advice or experience most appreciated.

dj]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14322 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14322 Sun, 12 Jun 2016 09:17:51 +0100 alexw
After recently pulling out from a house purchase (aided from some useful comments from this site) which would have involved a significant amount of work to make the home more energy efficient, we've decided to buy an off the shelf new build house on a new building site. I appreciate that perhaps a self build we could gain a higher level of energy efficiency but with two daughters aged 2 and 3, we are looking for the most stress free option.

Therefore, we have reserved a plot on a new site just outside Minehead in Somerset, but I have a concern over their design with a conservatory on the back of the house which has no doors between the main house and itself. Instead it is described as a family room, basically an open plan conservatory leading off the kitchen area. I have been reassured by the sales team that its roof is double polycarbonate roofing, and its a B rated house but am I right to have concerns that this will be cold in the winter months and defeats the object of trying to buy an energy efficient house? The conservatory isn't huge, approximately 3m x 3m. We have spoken to one of the neighbours who has the same design and the first comment they made was that the kitchen area was cold! This probably already answers my question, but I'm confused as to how it can be a B rated house?

Any thoughts or recommendations would be welcome. I have only committed £500 at this stage, so whilst painful I can still walk away.

Many thanks,

Alex]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14324 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14324 Sun, 12 Jun 2016 13:12:35 +0100 AMG Apologies for the long post. You helped me previously with window details.

I've just moved into my new build house that I have been constructing over the last few years.
It's an open plan living dining room.
The house is externally insulated apart from one side because a neighbouring wall (3 storey) is only 300mm away from my external wall. There is no space to get anything between the houses. As a consequence, this wall is internally insulated by constructing a timber stud wall with insulation in between. The make up of this side elevation is as follows render, block work, 100mm cavity, breather membrane, insulated stud wall, vcl, insulated plaster board, plaster.

Up until we moved in, no issues had been identified regarding any damp or smell. However, once we moved in a musty smell was apparent coming form the sockets. Taking sockets off, it was clear that builders had cut vcl to sink back sockets. I then bust open the back of sockets and you can clearly smell the damp stale musty air. I could not inspect the cavity between the breather membrane and externall wall. However everything appeared dry on the internal face of the breather membrane.

I have subsequently re insulated and repaired the vcl later. The smell has reduced significantly but it seems like there is still an odour which suggests that there is background leakage of air into the house. The building inspectors suggested drilling 50mm holes from the external wall so that the internal 100mm cavity can ventilate?
If this did not help the it would then require busting open the whole wall and doing an instrusive survey. .

Not sure how good the drainage is between the two houses (the 300mm) gap. Both houses have their foundations and the ground is made up. Possibly the rainfall is not draining away and that the smell is coming from the ground up.

The floor is a block beam with insulation and a screed for UFH.

What would you suggest re next steps? Make a hole to ventilate the cavity between false stud wall and external block work? Rip open internal wall and start again with possible tanking of floor/wall etc but not sure what system to use if this route is recommended?

I feel hugely disappointed and blame myself for not picking up on this earlier. I just did not see it smell anything.
If you cannhelpnwith any thoughts or advice that would be much appreciated.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14319 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14319 Fri, 10 Jun 2016 14:26:04 +0100 atmos74
I am a Newbie to the forum so apologies if this is in the wrong place.

I am currently designing a garden room. I plan to use Easypad plinths for my foundation and sit the timber frame on these. I want to insulate the floor with Rockwool between the joists. I will then place OSB board on top of this.

What I am unsure of is where I need to place a breathable membrane or vapour seal.
If I put a membrane over the ground and then a vapour seal between the joists and OSB, is this correct. I would also like to deter any pests from getting under the floor and into the insualtion. Should I put an additional breathable membrane on the bottom of the joists?

Thanks for your help!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266 Sat, 14 May 2016 19:09:13 +0100 jwd
Cheers]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14262 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14262 Fri, 13 May 2016 12:00:45 +0100 kentishgreen
Two of my extensions are 175mm SIP panels. These will be battened (to create 25mm air cavity) and have WRC cladding fitted horizontally.

I'm just trying to determine where to position the 88mm frames within the 175mm panel. As there won't be an outerskin of blockwork/masonry, will there be much of a difference thermally whether I place them inboard/middle /outboard? On a side note, I was going to have a 20mm gap between the window frame and SIPs so that I could add some slim PIR in there to reduce thermal bridging as much as possible.

There is an optional 'cill extension' that fits underneath the main window frame and is used to fit the cill onto. One option however would be to do away with this and have the window oversail the SIPs panel by 10mm (see photo) and fix the window cill underneath to the SIPs panel instead . Aluminium cills are to be fitted long enough to take the water away from the face of the cladding.

But then I'm also thinking to take the window inwards as much as possible to take it away from the elements outside.

Advice anyone?

Thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14257 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14257 Wed, 11 May 2016 11:54:07 +0100 richardelliot
Searching online I've found lots of companies offering their services and a couple of guides which are more applicable to multi-house developments. These look expensive or very onerous. I'm hoping there is a middle ground out there which is acceptable for a couple of CFSH credits.

I'm hoping that someone might have an example they are willing to share and I can use it as a template for my SWMB.

Thanks,
Richard]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14222 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14222 Thu, 28 Apr 2016 23:55:37 +0100 Gotanewlife
Thing is, he has to heat with wood, he basically makes big things (like roofs) out of wood for a living and sells his bone dry offcuts pre-palletised for wood burners so it is pretty much inconceivable that he would use any other fuel source (not that there is gas available) and whilst he will pay extra to get a massive 6kW electricity supply it doesn't go far....

So decision made, underfloor heating, wood burner with hot water to a TS. Weeeeelll. He will have a low heating demand. First question - what does that look like? - I have no idea, my guess is under 5kW but can someone please speculate a more accurate range. All the kit required for his wet system really adds up (he has pencilled in 15k (euros). But I have been wondering: what about fans in the walls. The internal walls are not yet final but decided is one main living room (kitchen, diner, lounge with large picture window across amazing view) and shortest possible corridor. It has already been established on here that MVHR just doesn't move enough energy around to transfer any useful heat but what about fans in the internal walls!?

So given a starting point of a simple stand alone wood burner in the lounge, minimal use of electricity and no gas how do you make this house work? Fans at ceiling height between the lounge and the 3 bedrooms maybe - there will be a size that would work obviously. If my fluid dynamics knowledge is right these fans wouldn't affect the MVHR if the internal doors are open but correct me if I am wrong. Or maybe a really over-sized MVHR. Wife has decided tiled bathroom floors so perhaps infra-red and/or electric underfloor in these 2 rooms.

It is a weird one but if anyone can come up with a solution it will be you guys!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14194 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14194 Tue, 19 Apr 2016 13:21:35 +0100 dsewell
Does anybody have any experience / recommendations regarding airtightness installation of intermediate floors?

The building walls are 215mm AAC Blocks. Floors are open web joists 220 high joists.

We are considering 2 options:

1) a laminated 50mm wall plate bolted to the block work, parge coat behind. Joists hung from wall plate. This option is favoured as easy to make airtight but our SE has reservations re bearing capacity of the bolts in blockwork / stability. We are struggling to find suitable details or bolts / fixings to take the loads.

2) standard joist hangers over the blocks, joists siting directly onto these. Considered more stable but far more complex to make airtight.

We have also considered other options such as plastic pockets, Tony Tray, etc.

The key points being to design a junction that will take the loads AND is very airtight.

Regarding option 1) can anybody recommend wall plate fixings that have been used successfully?

Regarding option 2) are there any techniques / products we can consider to make wall hangers airtight?

Any help would be greatly appreciated.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14217 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14217 Wed, 27 Apr 2016 12:23:18 +0100 kentishgreen
With a plethora of acoustic board products on the market, all claiming various dB reduction values, is there any particular product people here have experience of? Of course most manufacturers don't seem to test there product the same way, so working out the best dB/£ is difficult.

Most products have your typical foam+board product that is then bonded to the existing floor. I'm inclined to go for that rather than anything more complicated/pricey!

I'm only needing 34sqm of boarding on top of my 22mm egger board which are supported by metal webbed joists at approx 450mm centres. Finished floor will be carpet and vinyl (bedroom / bathroom).

Looking to spend no more than £25/sqm if possible.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14216 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14216 Tue, 26 Apr 2016 20:24:26 +0100 debbiel What insulation would people suggest for internal stud walls of timber frame house? It's just for soundproofing. Studwork is 89mm deep. I would like to stick with natural insulation.
Noise isn't a big issue for us, and we are detached so no party walls to worry about.
Also, same question for between ceiling and attic floor - attic is habitable with warm roof.
Thanks in advance.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12607 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12607 Tue, 30 Sep 2014 11:01:11 +0100 ringi
The claims:

“Micro 91°C AE Digester-Fuel Cells generate sufficient income from the waste stream of a house to pay the mortgage. For the cost of a sewage connection they generate 10-12kWh per kg of waste. An average family producing 50kg of waste per week continuously generates 4kWh of electricity and 6kWh of heat.”

:shocked:

How large a garden is needed to get enough feedstock for the Micro 91°C AE Digester?

How do you define “cost of a sewage connection”, is this the cost in a town on a “garden stealing” build, or the cost in the middle of nowhere?

What about rain water, most building plots in towns don’t have the garden space to put in a soak away given the 4m rule.

I thought that there was a requirement to connect to the main sewage if you could do so, I have miss understood this?

Why can’t the same setup be used for a CHP unit running on mains gas?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14193 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14193 Tue, 19 Apr 2016 07:15:26 +0100 Pugliese
I am now building in Italy and have been let down by our local carpenter. I now need to order for delivery in 4 weeks a small order of DG wooden windows and doors. I have previously imported from Poland (Polish Interiors) and been happy with the product but wanted to know if since my absence any other companies have been recommended

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14200 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14200 Thu, 21 Apr 2016 15:03:36 +0100 tony
How long will it be before we see plastic roof tiles over the whole roof?

How stable are these to uv and are they as durable as the tiles they adjoin?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14131 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14131 Wed, 16 Mar 2016 14:45:20 +0000 divorcingjack
We have just started clearing our site and have run into a problem which may spell the end for our planned insulated slab foundation due to additional cost.

The site has a lot of topsoil on it, approx 1.7m at the deepest point. Removing it is not a massive problem, but the level of the house cannot be dropped due to the need to get light into the interior over neighbouring buildings. Piling or pads have been suggested with ground beams and then the insulated slab on top. This would be the best suggestion, but I think it will be prohibitively expensive - basically like paying for 2 sets of foundations.

Our architect is of the opinion that we should remove the soil, dig strip foundations and form a block basement. The site is dry and free draining sand, so we think full waterproof concrete would be overkill. We would not be able to complete the basement at this point in time, but would like to have the option at some point in the future.

Basically, if we are going to have extra expense at this point, we would rather try and get a basement out of it. I am currently thinking of insulation to the base of the strip founds and up to ground level topped with a cast slab. Would this be possible to design in such a way as to mitigate thermal bridging to the basement below?

Any suggestions for a cost-effective way around this problem, much appreciated.

Thanks,
dj]]>