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  1. Did you blow the cellulose in yourself or get an installer to do it? Worrying there was voids that you discovered if using an installer?
  2. What airtight membrane did you use? Did it withstand the pressure of the cellulose pumped in?
  3. We are planning on a steico wood fibre board on exterior and passivplus interior serving as the vapour and airtightness barrier. Just wondering how we detail the junction of the board at the wall plate
  4. We are looking at propassiv as the internal substrate for our vaulted roof makeup. Blown in cellulose. Has anyone got a specific detailing for where the propassiv board meets the wall plate at the eaves. If the board is tight up against the inner leaf/wall plate it seems there’s going to be a tapered gap - is it best to foam this and then tape over? Anyone got any photos if they’ve done similar?
  5. Is it holding anything up? Got a drawing?
  6. I think I priced up the celotex to be more than the cellulose? Granted I could have shallower rafters with celotex but then id need insulated PB to hit the same u values? maybe I’m over engineering / thinking it
  7. @JohnMo we were told that where the rafters hit the valley they'd need cutting at angles and not ideal for pozi rafters? We've got two 45 deg roofs connecting at 90 degrees to each other - all vaulted. You got a picture of your roof? I've heard issues with spray foam and mortgages as well?
  8. Thanks @Dave Jones - have you used before and if so which would you recommend? Struggled to find any online at least for a 200mm cavity.
  9. Just looking at detailing around the windows and doors and was looking at the Eurocell cavalok cavity closers (the ones where it's a single piece and tied in to the inner block during construction (see video below) More money, but I wonder whether its useful for the window fitters, and better for airtightness.. Worth the added cost?
  10. Thanks @Iceverge - I'm trying to minimise installation effort so was trying to get a rafter depth that meant I could just use blown in cellulose. Whilst I could extend the depth of the rafters internally, with the additional labour and timber, I wonder if I'd be better off just going for deeper rafters or I-Joists like @joe90 mentioned - even if there's additional cost?
  11. Did you full fill or manage to create a cavity somehow? What’s the performance like?
  12. Thanks @ETC will do once I’ve got the section drawings back. Only got elevations and planning drawings at the moment, unless you can work it out from these and floor plan.
  13. @joe90what did you insulate with?
  14. The only option for a shallower rafter is PIR. We did that on our previous build which also had attic trusses/ rooms in roof. Whilst the h value is okay the top floor gets very warm in warm weather due to the lower thermal mass (or whatever you call it) of the rigid insulation. I also don’t like the fact that timber shrinks, PIR then isnt tight and thermal bridging increases and performance is affected. if there’s another solution that gives high mass and low thermal decay in a smaller rafter am all ears?
  15. Has anyone any experience of a loose cut roof with 300mm deep rafters? We were looking to use posi rafters at 304mm to get the depth for blown cellulose but it doesn’t appear to be a good fit as we’ve got two roofs running into each other with rooms in the roof. It’s looking like attic trusses are out for the same reason. I believe we can get 300mm rafters which might work, or could potentially look for an engineered I-beams. Any gotchas with this approach?
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