Need dorma advice

[bryntwr]

Hi All,

The old cladding on my dorma has rotted away, so I've decided to replace with plastic. Unfortunately there isn't any insulation in the cavity and the ply boards extend into a lower section of the house which I cannot remove it would cause damage. As a solution I've decided to batten to 70mm and add 50mm of kingspan insulation instead of removing I've basically built out. What I want to know is, as the cavity hasn't been filled but there is insulation on the outer skin, will this act as insulation should or will the cavity gap I couldn't fill cause a problem?

Another problem I have is the window tray. If I batten out to 70mm and then add ply and cladding on top it will be past the window drip tray. I can't remove the tray or window as its tiled inside. Any solution for this?

Thanks
Owen

 

[theprinceofdarkness]

i think I would have lined the window reveal in plastic on a wooden frame, so the actual window frame could out through the opening. If this have the typical plastic window sill, then this would stick out further then your present one, so shielding the top of your foam and outer cladding. it would have been a good place affix the top of your flashing. The top of the window aperture also needs a drip rail and a decent water seal.
Frank