Valinor

For anyone else interested in this, I ended up calling Gyproc and spoke to their technical team - with them saying that technically Duraline is the better product acoustically. Interesting. I wonder why they even make Soundbloc..

I was wondering why people go for Soundbloc, considering Duraline has a higher mass at the same thickness /m2. Does anyone know why someone would prefer Soundbloc for soundproofing? Am I missing something? Duraline 14.1kg/m2 Soundbloc 13kg/m2

Thank you for both your replies! Yes PIR has gone up in price and that's a very good idea. Will need to mull it over as I do appreciate the insanity of trying to do it as it was originally planned!

Thanks! In this specific place it's the 110mm soil pipe and there's one continuous run all the way under the slab (just looked at what they sent building control). There's another place where another soil pipe runs through a footing and over there they sleeved it in a 200mm pipe with additional joins to the 110mm on both ends. I shall attempt not to be paranoid about rodents; will chicken wire it with spray foam and bury the whole thing!

Thank you for taking the time to reply Unfortunately we purchased all insulation before the March price rise, we've got 450mm x 1200mm though without tongue and groove as those were too expensive (we went for Recticel Eurowall - PIR Cavity Wall Insulation Board) When talking about cutting I meant for all the areas around a window opening or where building control specified more brick ties (where I imagine I can insert a knife into the PIR and the wall tie will go straight through. I still want to tape the joints of the factory perfect edges etc. To prevent the brickie pushing mortar out the back - would it make sense to try and convince him to bed the mortar more to the inside, with there being less of it on the insulation side and likely to push out that way? Or would that weaken the walls too much from a structural point of view?

Due to site constraints we had to do the outer skin first, and will be now adding the insulation and building the inner skin from Celcon blocks. A few questions I have which I would appreciate any advice on ? How come in some images the insulation doesn't go to the bottom of the cavity? Wouldn't that reduce the wall's insulation properties? Is there anything wrong with going all the way to the bottom of the cavity? As I'll have to cut and place the insulation in the cavity before we lay each course of blocks against it, I was wondering whether it matters which side of the insulation I place tape on. As in, looking at the illustration below, from left to right, would this be ok at preventing airflow? bricks - 25mm void - 75mm PIR - tape - Celcon blocks. Or should I go to the effort of trying to tape on the side with the 25mm void? Any tips for making sure there is no gap between the PIR and Celcons when doing it in this order? Anything I should pay attention to when helping the brickie? I would have much rather had the Celcons up first and been able to place the PIR against them etc, but that wasn't possible. Thanks!

The pipe doesn't have flexible joints on both sides of the wall - it just goes straight through from the manhole all the way in. Wouldn't a lean mix embed it in place too permanently?

A question about pipe through lintelled opening. My groundworkers just left it buried all the way above the lintel, and by looking into the cavity I saw there was soil inside (in the cavity) which made me dig up what’s seen on the photo from the outside (the pipe continues under the slab where it's encased in gravel). How would you go about rectifying this? It’s a massive hole and I don’t want any rodents getting into the cavity through it in the future (the concrete fill in the cavity is about as high as the lintel on the sides, but where the pipe is it’s open going all the way up). I saw someone online using spray foam, but that doesn’t seem rodent proof if they can easily chew through it? Someone else suggested I block it up from the outside and fill the whole thing with concrete to match the level of the remaining concrete in the cavity void; but I imagine that defeats the purpose of the pipe being able to move? Any suggestions would be very welcome!