Overboard or remove?

[bsr]

Hello

I am internally insulating my full-width dormer. I intend to do this with Thermaline or similar - 50mm PIR insulation laminated to plasterboard. £50 a sheet

Currently the dormer face is (from inside to outside) 1/2 inch plasterboard, 2x3 studs with fibreglass in between, DPM, and PVC cladding.

To save some cash I was going to overboard myself and then get them skimmed - is this best or would a plasterer prefer to do the lot? I'm guessing they wouldn't sort the window boards or extend the radiator piping!

1. Would you overboard or remove the old plasterboard?
2. Is it easiest to remove the old window boards and fit new?
3. How do I detail around the window reveals?
4. Would you fix with 100mm plasterboard screws, tape and skim?
5. Any other tips?

Thanks


bsr

 

[HERTS P&D]

By the questions you are asking...........I would suggest you get someone in.

Andy

 

[cdbe]

Remove existing plasterboard, replace existing fibreglass with 75mm celotex between studs, overboard with 25mm celotex, tape joints with foil tape, overboard with 12.5mm plasterboard, skim - only a 25mm increase in overall thickness. I think you can get 20mm celotex, if you use this with 9.5mm plasterboard you might be ok round the reveals. Windowboard - depending on what it's made of and your skills - replace, extend or move forward and fill in the gap at the back and cover with pvc fillet.

 

[bsr]

cdbe that's great, thank you.

 

[bsr]

Job done but with 50mm celotex on the inside. Your help was appreciated! On the reveals I foamed on 9.5mm board as you said. I think the room is holding heat better. Time will tell.

It's strange, i easily found plasterers willing to do the skimming but they weren't interested in the insulation work. Seems to me to be easier money than skimming!

I am beginning to love Soudal low expansion adhesive foam. It sticks anything.