Economical way to combine soundproofing and UFH

[PeterW]

P5 water resistant chipboard is used pretty much across the industry - the Egger protect type boards with the coating on can stay in the rain for 60 days with no real issues so being in a dry house they will last for decades. 

[joe90]

My egger p5 boards were out in winter rain fir months before the roof went on (I was a little concerned) but they did not suffer at all, it’s tougher that some think, it’s not “chipboard “ as some know it. Conversely I have seen ply de laminate quite quickly in damp conditions .

[Adsibob]

Just to update everyone on where I am with this:

we are installing 40mm Kooltherm K5 Phenolic Foam EWI on ALL the old external walls.

Internally, we are not insulating the ground floor walls because we are advised that this would increase our risk of interstitial condensation for our specific situation. 
At first floor we are using insulated plasterboard though, which contains 35mm of PIR, on the walls.

at second floor (loft) we are using wood fibre mainly, to bolster decrement delay. See attached build up which shows all second floor build ups:

 All windows are double glazed with no bridging between internal and external aluminium frames. They have an energy efficiency of A+, whatever that means.

 Still can’t decide whether I need heating in the loft and what type.

[Adsibob]

So any comments on my walls and roof build up and the conundrum as to what heating system to have up there, if at all...?

[Iceverge]

What is your plan for a vapour control layer in the above buildups?

 

I note the membrane is floating between the batten and counter batten in all cases. Why here and not below the counter-batten?

 

As for the heating probably not but impossible to say without knowing the specific situation. If you're doubtful just run pipes anyway for rads. 

 

 

Why double glazed and not triple? 

[Adsibob]

31 minutes ago, Iceverge said:

What is your plan for a vapour control layer in the above buildups?

 

https://www.dupont.co.uk/products/tyvek-supro.html it is vapour permeable, breathable and water resistant

 

31 minutes ago, Iceverge said:

 

I note the membrane is floating between the batten and counter batten in all cases. Why here and not below the counter-batten?

No idea I'm afraid. My architect designed it, I then asked him to run it by a RICS surveyor who designs these sorts of things and he made some tweaks and this is the end product. Couldn't tell you which way is the right or the wrong way to do these things. Why do you think having the membrane floating between the batten and counter batten is wrong?

 

31 minutes ago, Iceverge said:

As for the heating probably not but impossible to say without knowing the specific situation. If you're doubtful just run pipes anyway for rads. 

Yeah, that's a good idea. The only downside is that if I don't end up needing to install radiators, we'll end up with pipes sticking out the floor.

 

31 minutes ago, Iceverge said:

 

Why double glazed and not triple? 

Because of aesthetic and cost reasons. We are having crittall style windows made by MetTherm. We really liked their slim frames, look very much like the original steel frames, but made from aluminium and much better insulated than the steel ones because they are thermally broken whereas steel are not. They don't do 3D so if we had insisted on that, we would have had to go with something very bespoke to achieve the same look. We have fairly large windows on the rear elevation, so we will get some heat loss vs 3D, but that will be partially mitigated by the solar gain, as most of the windows get good amount of sunshine. It's not a passive house, just a refurb of a very poorly maintained 1930s house.

[Iceverge]

12 hours ago, Adsibob said:

https://www.dupont.co.uk/products/tyvek-supro.html it is vapour permeable, breathable and water resistant

That's your external moisture barrier. 

 

 At the moment the moisture from the house can escape between the joints in the kooltherm into the roof and get trapped in there by the sarking which is cold and cause condensation.  

Carefully taping the joints in the kooltherm should help, 

 

 

12 hours ago, Adsibob said:

No idea I'm afraid. My architect designed it, I then asked him to run it by a RICS surveyor who designs these sorts of things and he made some tweaks and this is the end product. Couldn't tell you which way is the right or the wrong way to do these things. Why do you think having the membrane floating between the batten and counter batten is wrong?

 

No it's an approved detail for permeable roof coverings. In my opinion the membrane is more likely to rip and you'll need to make sure that the builders leave the correct droop under the battens. I'd put it under the counter-battens personally. 

 

12 hours ago, Adsibob said:

Yeah, that's a good idea. The only downside is that if I don't end up needing to install radiators, we'll end up with pipes sticking out the floor.

 

Given your other two options are having radiators that will be never used or cold rooms I think you're going to have to compromise somewhere. 

12 hours ago, Adsibob said:

Because of aesthetic and cost reasons. We are having crittall style windows made by MetTherm. We really liked their slim frames, look very much like the original steel frames, but made from aluminium and much better insulated than the steel ones because they are thermally broken whereas steel are not. They don't do 3D so if we had insisted on that, we would have had to go with something very bespoke to achieve the same look. We have fairly large windows on the rear elevation, so we will get some heat loss vs 3D, but that will be partially mitigated by the solar gain, as most of the windows get good amount of sunshine. It's not a passive house, just a refurb of a very poorly maintained 1930s house.

Fair enough. I'd be interested to see some real world pics of those windows when they come. They sound nice. 

 

Out of interest where are you planning on running services on the ceilings and walls?  

 

[Adsibob]

2 hours ago, Iceverge said:

Carefully taping the joints in the kooltherm should help, 

Thank for reminding me about this. It is a spec that the surveyor recommended, just the architect forgot to include it on his drawings.

[Adsibob]

2 hours ago, Iceverge said:

Out of interest where are you planning on running services on the ceilings and walls?  

 

We have posi joists under the first and second floor, so this will help. The internal walls are all studs, so that too will provide a void for services. As for the channels within the external wall, I'm not sure! I need to double check, but I'm hoping the builder and/or architect has thought about this!

[Adsibob]

2 hours ago, Iceverge said:

Fair enough. I'd be interested to see some real world pics of those windows when they come. They sound nice. 

They're very nice. Really happy with the frames. Some of the glazing units had to be replaced though due to some issues. Mostly boarded up now, but once we unboard I'll post some pics.