gravelld

Don't understand this reasoning but I love the analogy Can you explain?

@Declan52 this is old render, not a new job... is that what you thought I meant?

Don't be sorry, I want honest opinion not sympathy Guide m2 price for just a silicone render, no insulation? I'm guessing around £90-100/m2 for EWI. Can it be rendered over the top to reduce the labour in knocking the existing good bits off?

@oranjeboom Are you confusing ACH with m3/hr/m2?

TL;DR: scroll down to "So my questions are about the render" or if you fancy a read about the context... We have a fully rendered house. The render is about 15 years old in its newest spots, maybe 20-25 years old elsewhere. The render is sand and cement. The problems with this are: It has popped (taps hollow) in the more exposed locations Rusted corner beads There are cracks everywhere Signs of water ingress in some of the worst places Numerous bits crumbling away around the bead at DPC level My original plan was to install EWI at the same time as also replacing the windows (which are also in a bad state of repair). The trouble with this is the cost. Not only in terms of the EWI, but in terms of what the EWI has a knock-on effect on. For example: Making sure EWI meets loft insulation Digging, parging, insulating below DPC Moving drains Bricking up windows that are overlapped by insulation Converting lean-to roofs to warm roofs. Moving the electricity meter Changing other services running in and out Probably replacing rainwater goods Probably replacing soffits/fascias I definitely intend to install EWI in the future. The reality for most people though is that this is extremely expensive. So I wondered what my other options were, and if I can make this project much financially tolerable for my family. Here's what I know I can do to plan for the future: Follow details to allow new windows to be moved into the insulation layer later Get the cavities fully filled (currently crap partial fill - will source some sort of foam... or something) If I have a lower initial project cost, I can spend a little more on quality for what I am actually buying, e.g. window quality If I were to not install EWI and just fix the render, I would want at least a decade, I would hope, to save for EWI with ideally NO maintenance in that time period. So my questions are about the render: Is there much point in "patching up" S&C render? What should I fill the removed sections of render with? Won't other areas go, or crack at the join between the two? Is it better to rip the lot off and start over with a modern render, e.g. silicone? Could we render over the top of the existing render? (This would reduce the space for insulation later if we also don't convert the roof to a warm roof at the same time). Would really appreciate people's knowledge on this one...

Only worry I have in this location with cellulose (on the external wall) is if it gets wet... somehow. But then if you have a torrent going in obviously you've a problem with EPS too. I'm also guessing it's a bit more expensive. I get some decrement delay and thermal capacity because the existing structure is masonry. Maybe cellulose is inherently more airtight though, which would be good against the old external walls, which will form the new AT layer being rendered.

I haven't been keeping up with Mr Luxton's blog, thanks for that, will check it. Just took a quick look - looks like he's blowing the cavity with EPS bead, which is what I was going to do (or use cellulose). I took a look at the prices for the Steico products - they make a wall joist. Might be worth talking to them about whether this could be used. I took a look at their price list at http://www.steico.com/fileadmin/steico/content/pdf/Marketing/UK/Price_List/STEICO_pricelist_int_i.pdf From my calculation it looks like around £3.5-4k for the i-beams. Thanks so much for your input @bissoejosh

As an addition to an existing masonry building, so not structural, which is why Larsen Truss is perfect. @bissoejosh I'd be really interested in any research you came up with. Do you not think using I-Beams is overkill and therefore more expensive? Furthermore, I would prefer not having the web continuous down the length for thermal bridging reasons. I thought a local joiner would also be able to come up with the trusses, so I'll need a schedule of trusses. It would be interesting to compare prices with any suppliers of Larsen trusses (if they existed).

Initially I'm looking at getting a price estimate so I can compare with the normal EWI sticky block route... Thanks for the new keywords to search Google with! I'm thinking I-Beams or webbed joists might be a bit over-engineered, just need something like http://www.greenbuildingadvisor.com/blogs/dept/musings/all-about-larsen-trusses (see the pics at the bottom). I was hoping that if a firm was already making similar components I might be able to bring the price down due to scaling effects (e.g. they already have the machines set up to quickly mass produce).

I found an interesting company in Germany who make timber components for all sorts of things, including trusses for installing EWI in. The company is Lignotrend (https://www.lignotrend.de/en/home/) and here's an example product I'm interested in: https://www.lignotrend.de/en/products/certifiedcomponents/b21-daemmung-wand-sanierung-mauerwerk-fachwerk/ They don't seem to have a presence in the UK. I sent them an email, but not hopeful for a positive outcome. If I wanted to find a UK firm making something similar, what do I search for? I don't even know what you'd call this type of company!

Sorry - missed (a). But (b) can still be a difficult one to argue *if* you also have a ventilation system and it comes down to who you ask. Last sweep I was talking to about was saying a lot of HETAS peeps aren't happy about signing them off with ventilation systems, although BC tend to be more allowing.

Assume these are all supply only prices? Not installation?

Do you also have to consider the ventilation requirements - you can get conflicting advice on this too.

Except coolbox packs aren't normally 1.2kg right?! (For obvious reasons). ?

Seems to me the obvious solution if space allows is external shading. Sounds like you're well on the way already but what about some crazy, "statement" overhangs to the south elevation? Personally I'm not comfortable with the Ph overheating allowances... Remember it's an average too, not what the overheating is in one specific room...

That will kill all weeds eventually, the trouble is not all places are accessible to a lawn mower. Even strimming can be difficult depending on the surroundings. I know it's bad, but I use R*****p (Glyphosate based). I read it's best to do it in Autumn, and that's what I did last year. I make up a solution in a sturdy container and drape the brambles, leaves etc inside it for a few days. Cover and make sure no chance of tipping over. After that, take it out and drape it on plastic sheeting to dry off. Then it takes about a month or so to die! Would like to know what SBK is, best I can tell is that Peter is suggesting you host a round of the World Superbikes in your back garden? I guess that would work...

So are they only replacing the render/coats, or do they take the boards off too?

I can only talk of the Liebherr wine fridge I have which is enormous and seemingly very well made. They always seem to do well in energy efficiency ratings.

Use an IR thermometer to check the temperature - I think there's a way of calculating whether a current will occur. IIRC the recco is to have the inner glazing *pane* at 16C so that most won't feel a downdraught in even the coldest external temperatures. However, for a *frame* maybe we can be more lenient because there's much less surface area. That said, it might be the pane contributing to it.

In the case of a draft doesn't it give very variable results, even as you hold it? Just imagining different wind speeds, moving the stick a few cms by accident...

Can you briefly describe your method? I thought this was only used where you have control over where the air movement may occur, e.g. for measuring pressure from ventilation outlets.

There are interesting discussions about filling voids under floor boards, see Sophie Pelsmaker's work and also discussions in GBF.

Foam also gets eaten and the adhesive layer can detach. The AT figures given for foam is for the foam itself, not the foam installed, if that makes sense. Foam is not a solution for AT.

Are they penetrating the AT layer? If not, I don't see the problem...

I am performing a fabric upgrade on our house. Work to be done includes: - EWI - New windows, doors - Establishing AT layer - Digging out foundations for EWI - Designed ventilation - Resizing of window openings (enlarging and shrinking) I have done: - Overall aesthetic look (it's not really changed much, but thicker walls and more contemporary look to the joinery) - Energy model - Generic details for important installations, e.g. window installation, treatment of eaves (before deciding on manufacturers) What I need to do: - BC approval - Planning approval (don't think there'll be much of this, not listed nor in conservation area) - Choose suppliers and products - Update details to follow systems chosen - Arrange finance What should my ordering be next? I don't want to get BC approval only to find our budget won't work for what we have got approval for! Should we finalise the entire design first?