What is the general advice on insulating window reveals where there are brick returns rather than a gap around the reveals and the house has insulated cavity wall.
From what I understand, choices are:
1) PUR board insulation around the brick return followed by plasterboard. The problem with that is the extra thickness of the insulating board reducing size of the window. Also what do you do where the reveal meets the internal wall? I presume you have to insulate that bit as well but that would start reducing amount of leaving space. Also, my plasterer believes you need airgap between plasterboard to allow any moisture to pass through
2) Removing brick returns and replacing with cavity closer/insulation. I think that would create structural problems and would require installation of extra cavity ties as part of the job. Its also a big job.
3) Plasterer preferred option - battens followed by plasterboard with air gap in between. Plasterer believes that airgap is better than insulation as it allows moisture to pass through rather than wall sweating as it would with insulation. He's right but he's also quite old-fashioned.
)
Any thoughts if these are the only options and any other potential problems.
From what I understand, choices are:
1) PUR board insulation around the brick return followed by plasterboard. The problem with that is the extra thickness of the insulating board reducing size of the window. Also what do you do where the reveal meets the internal wall? I presume you have to insulate that bit as well but that would start reducing amount of leaving space. Also, my plasterer believes you need airgap between plasterboard to allow any moisture to pass through
2) Removing brick returns and replacing with cavity closer/insulation. I think that would create structural problems and would require installation of extra cavity ties as part of the job. Its also a big job.
3) Plasterer preferred option - battens followed by plasterboard with air gap in between. Plasterer believes that airgap is better than insulation as it allows moisture to pass through rather than wall sweating as it would with insulation. He's right but he's also quite old-fashioned.
)Any thoughts if these are the only options and any other potential problems.
