We’ve got wooden sash windows (6 years old) that have always shown signs of water ingress to the (painted mdf) internal sills (blown/misshapen) and the walls below and to the sides of the sills.
We had the window installation rechecked by the installers/manufacturers (they said all was fine) and assumed the issue must be external, so had the external lead flashing around the external sill beefed up. These windows are very exposed, but still the issue continued.
I’ve finally got around to ripping off a rotten internal sill and found the cavity below the window to be soaked, including the insulation behind the plasterboard.
Between the internal sill and the external sill there is only expanding foam. What should I do within this cavity to prevent water ingress from travelling through the cavity to the insulation, plasterboard and new internal sill please
We had the window installation rechecked by the installers/manufacturers (they said all was fine) and assumed the issue must be external, so had the external lead flashing around the external sill beefed up. These windows are very exposed, but still the issue continued.
I’ve finally got around to ripping off a rotten internal sill and found the cavity below the window to be soaked, including the insulation behind the plasterboard.
Between the internal sill and the external sill there is only expanding foam. What should I do within this cavity to prevent water ingress from travelling through the cavity to the insulation, plasterboard and new internal sill please