Internal wall insulation is the fitting of an insulating lining on the inside of the outer wall, usually with mineral wool or PIR insulation. This solution is chosen when the exterior of the facade may not or cannot be altered, for example on listed buildings or where a valuable facade appearance must be preserved.
Application
With internal insulation a timber or metal batten frame is set against the existing wall and filled with insulation. Over this comes a vapour-control or vapour-tight layer and a finish such as plasterboard. It is a solution where external insulation would damage the historic brick or masonry, or where the building line or plot boundary does not allow a thicker outer wall. The work is done from inside and can be carried out room by room.
Characteristics
Internal insulation requires careful attention to building physics. Because the wall stays cold on the outside, condensation can form within the structure; a well-executed vapour-tight layer is therefore essential. Cold bridges at connecting floors, walls and joist layers are also a concern, as heat loss and moisture risk occur there. In addition, a small amount of floor area is lost. A well-considered design and the right choice of materials prevent moisture and mould problems.
Related terms
- insulation
- facade
- mineral wool
- cavity
- brick
- structure
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