-
A day
swoon
It looks great. Probably a stupid question, but you screwed the insulated board onto the battons right? Which then leaves a small air cavity the depth of the roofing battens?
hugo7-
Yep that is correct. And I left the battens a bit gappy so nothing is fully fully enclosed - just in case. Kingspan/celotex/ecotherm all have guides on the subject. CharlieDIYte on YT also has a video - although he did dot and dab.
Your north wall/lowest point on the roof/air brick scenario is exactly the same as ours. Knocking back to brick wasn't an easy decision but am glad I did it - the room was small enough as it is.
I used these boards https://www.selcobw.com/products/plaster-drylining/plasterboard-accessories/plasterboard/gtec-thermal-pir-tapered-edge-2400-x-1200-x-37-5mm
Many thicknesses to choose from, I elected for 37mm which has 25mm of PIR insulation. It would not meet current U value requirements, but provided you aren't doing more than 50% of the walls in the room, you don't need BC sign off, and I felt the improvement with 25mm would be sufficient.
Hovis
Been having some christmas DIY adventures. Son's bedroom too cold and required electric heater in addition to the CH to keep above 16 deg, so decided to insulate. The construction is 1930s single skin solid brick wall, external corner of house.
I drilled a few test holes to see how thick the plaster layer was and if it would be worth stripping back to gain a bit of space that would be lost due to the insulated board. Found to be 30-40mm so concluded yes given this is London so out came the SDS. A day of messy messy physically draining work and I had it stripped back to brick. Was very pleased to see everything very dry which confirmed the damp we had on the walls was due to condensation.
I had two options for attaching the insulated boards, dot dab adhesive, or battens and mechanical fixing. Kingspan recommended mechanical fixing for single skin construction in case of water ingress and potential failure of the dot and dab. Shame because it's a much more laborious method (and probably would have been fine given how dry everything was). But I'm not a risk taker so I ordered a bunch of roofing battens, dpc roll and got to work.
Lots of window packers and messing around to get it flat. I took the opportunity to add an extra socket on one of the walls and replace the radiator whilst the carpet was up.
Insulated plasterboard went up easy, inflatable wedges are very handy. I cut them all with a track saw (!) and an old blade for a dust free experience. 100% would do this again. I rough cut the windows out in situ with a jigsaw, which I will cut to actual size when I do the reveals. I went for tapered boards so I could tape and joint, something I felt I could DIY, rather than a skim which I don't fancy ever trying.
Taping and jointing is however more difficult than it looks. I truly suck at it and lots of sanding is happening using an RO sander + dust extractor again for dust free experience. I used Easy fill 60, mixed in a metal bucket with a paint paddle mixer and worked fast with 100, 150 and 250mm taping knives. Paper strips at the joints.
We're getting the windows redone so I can't finish the reveals and cill until thats done, but they will be getting insulated too, just mechanically fixed straight to brick this time.
Upgrade to warmth is major, long may our son slumber when he returns.
Up next, more sanding, skirting, picture rail, paint , carpets back then wait for windows.