G and J

Why not use smaller screws so they don’t go through both layers? i.e. 25mm plus payload. I’m trying to get my head round airtight. To check my thinking: We test at 50pascals. I think that’s equivalent to less than 6mm difference in a water manometer. So it’s sod all in pressure terms. So unless an ex screw hole is huge and ragged, even if there’s a few dozen of them, would that make a difference? Have I got my sums right?

Ummmm, isn’t that a but too big for a domestic plant room? 😉 Being serious I am sort of facing a similar set of worries. Our airtight layer is our VCL, and we are stapling that up. OK, where we can we are putting the staples on the edge outside the tape so on the non airtight side but still, there are a good few places where the staples pierce the membrane. Where a staple is removed or pulled out we should probably put a bit of tape over it, and that’s ok as none of our membrane will be visible. But your walls will look like they’ve got measles lol Presumably you’ll be painting your the PPB, so can’t you simply fill and paint any screw holes from removed screws? I suspect comments about air gaps in mortar are more relevant as there will be thousands of ‘em and they add up. But I’m sure a grown up will be along shortly to confirm. As for plant room and a service void isn’t it just your preferred aesthetic?

Isn’t that the root of the cladding problem with Grenfell? I can easily see me falling into that particular pitfall. Trouble is, when one is scribbling away, it’s so seductive thinking one has come up with a really neat solution (“why had nobody else thought of this? Gosh I’m clever!”). Sigh.

Now he tells me......

The screed was 100mm thick, they used a pump, but it was a dryish mix, Josh shovelled sand (16ton) and cement to match like a trojan....and Jason achieved a really flat result, very happy with the job they did. No we didn't staple the upstand at all.

We used the u heat version (yellow rather than blue, but looks identical) the upstand on our was stiff enough to be self supporting Apologies for poor image but there's nothing supporting it in front of the sliders and we didn't staple, but as you can see screed was traditional sand and cement

Sorry to be über boring, but how bad is the existing building?

Not me, but G, and not finished, but have a look at our blog......demolished bungalow and timber frame build

We have just ordered a pocket door (frame and solid flush door) for a gap 1200w 2350 high from these guys Em-b.co.uk Don't think they do doorcwithout frame, didn't ask as wanted to come as a set

Forgive the interrogation but… Are your fancoils on their own zone or together with your UFH? I ask as we are installing our main bedroom fancoil as part of the single zone, but with the ability to zone it off later if needed.

We are building timber frame and had planned a render on board and circa 70% larch cladding. Because of the type of people we are, and you never know, we did some research to ensure the result was mortgageable, by either as as a equity release in years to come or by others should we decide to sell. We found several instances in mainstream lenders of more than 50% cladding being a no go, and other requiring more than 50% block. In the end we have a block skin to the ground floor and less than 50% wood cladding backed by cement board on our boundaries.

Presumably that data is for open ground. Under my slab will, I imagine, be rather different. It’s dry ground, no watercourses or the like. So what temperature should I use for my heat loss calculation for the underfloor insulation? (This particular horse has now bolted, but it’s still of interest.)

Do you use the fancoils much?

Thank you. That’s a well done for J. I did the polystyrene and the (*&#£*!!! ing) PIR in the floor. J does the walls.

Just looked back at our quotes from our local Jewsons. EPS70 was less than £47/m3 PIR (foil faced) was less than £87/m3 Both for 120mm thick 2.4m x 1.2m sheets held in stock locally at their suppliers.