bissoejosh

Plywood painted for fireproofing? Also how deep are your joists, if money is tight you might find alternatives to Kingspan a fair bit cheaper if you've got the depth to meet regs. Frametherm, Rockwool etc, all much cheaper but need more depth.

I was thinking a reduction to something like 40/50mm might make fixing easier especially if battens are added to the mix.

Also 280mm of PIR is quite a lot of insulation - nothing wrong with it but a thinner layer might make things easier if it can work with your SAP etc?

I'd do it the other way around. Insulation then batten - the screws for which could be long timber screws to sandwich the whole lot together. The other advantage is this gives a service zone for cable runs / light fittings and also a safety margin for your vapour control / airtight layer when fitting plasterboard screws.

Are you having a service cavity under the 80mm? Won't the battens that create this do the job of fixing the insulation / plasterboard long term - could just be long wood screws I'd have thought.

Ours is similar to @MikeSharp01 with twin parallel sole plates made of 45x95mm timber with insulation in-between. Only difference is the sole plates are concrete screwed into the block work below with a closed cell foam gasket beneath the timber and DPC. This was detailed by our frame engineer at my request as the original plan was a 300mmx45 glulam which seemed a fairly large cold bridge.

Option 3.

Cromar Vent 3 Pro, really tough and cheaper than some

I really like that, out of interest what sort of width is the overall Southern elevation?

Ah you were lucky, I must have just missed the switch. Annoying as I'm having difficult sourcing the order elsewhere.

They no longer sell via the website.

I'm also looking for membranes / tapes as Passive house system no longer sell via their website unfortunately. Anyone found any alternative suppliers?

Our cavity is roughly similar to conceal guttering but our BCO didn't mention anything regarding fire risk. If you're not within the boundary distance limits I cant see the issue.

Yes, paid an engineer who works alongside the design firm that did our timber frame and then had the whole lot CNC cut from machine file. All signed off by building control etc.

Here is the assembly drawing for the ridge beam element and supporting post. The same mortice and tenon join is used on our glulam frame for our sliding door opening (4210x2110mm) also pictured. I've also got the original engineering sketches but I don't think they show any more detail.

Do you definitely want to use joining plates? We've got a 140x450mm 14.9m glulam ridge beam that came in 3 pieces, one join supported by a wall the other a 140x140mm glulam post. The main beam is half lap jointed. No steel other than the threaded bar. Our post is a mortice and tenon join all pre cut. I can attach the engineering markups if it helps?

Many thanks everyone, certainly looks like a viable option if the beam and block can be levelled with sharp sand - I'll get the level out in a bit and see how bad it is. It's likely that the finished flooring could take a while so how would these sort of panels work if they were then covered with something like T&G OSB or Chipboard? Another option would be to do as @dudda did and build to the OSB level then wait until we're ready for the final covering before fitting the UFH sheets. I'm thinking of potential damage whilst construction continues to either the EPS or the piping as realistically the final floor is at the bottom of quite a long list!

When people use overlay board instead of screed what is the best method of heat distribution for an UFH system assuming a build up of approximately 200mm insulation, 22mm Chipboard all bonded together? I'm considering this for our upper ground floor which is on beam and block and has an available depth of 240mm. Site access makes screeding quite challenging and a pumped option isn't within the budget. Further advantages are more depth for insulation and zero drying time but I need to get my head around the UFH components before deciding. Many thanks

That would be really helpful thank you.

I like the look of this. Is it just an L shaped section?

We're doing something very similar and are using a replica of VHL7 on this link. https://www.vastern.co.uk/cladding/halflap-cladding/ Looks like rain screen but is closed up by the half lap. We're not actually getting it from Vastern as we're having home grown larch machined by a nearby sawmill but if you want Siberian Vastern have been really helpful.

I'd look at ICF which can be the retaining wall and the insulating external wall in one go. Spend plenty of time looking at waterproofing and warranty requirements.

Thanks, did you opt for the standard insulation thickness and then the fix separately sourced EPS on the outside (third pic?)? If we get permission on our second site I'm seriously considering ICF.

Good work, looks great. Is that Amvic ICF? How did you find it, any problems with the product?

Sounds like good advice, I'll hold off for the time being but keep an eye on what's out there. @Gav_P £250 sounds like a bargain!