Damp and Mould is the fifth blog in a series exploring retrofit. In this one we explore why your house may have damp and mould.
There are many reasons why your home can develop damp and mould – here we look at some common examples, and what could be causing them.
- I’ve got condensation running down the walls and mould patches are appearing since I had cavity wall insulation installed.
This looks like the ventilation wasn’t increased sufficiently at the same time, or maybe the cavity wasn’t suitable for insulation, or the insulation was installed incorrectly, or a combination of reasons.
- I’ve had the loft and the cavity walls insulated, but there’s a small section of sloping ceiling between the top of the wall and the insulation in the loft, and black mould is growing there.
This could be a cold bridge where the sloping ceiling wasn’t insulated.
- I’ve got damp walls on one side of my 1970’s house near to ground level and the wallpaper is starting to go mouldy and peel off.
There could be rubble in the cavity and the cavity wall insulation might be wet.
- I’ve got damp walls on one side of my 1850’s house near to ground level and the wallpaper is starting to go mouldy and peel off.
Has there been some “improvement” work that wasn’t using the right materials? Perhaps the wrong thing was added, or something done in the wrong way or the wrong place.
- I’ve got a damp patch on the ceiling and down the wall.
A possible leak in the roof, the guttering or around the chimney perhaps.
- I’ve got random damp patches on one wall of my 1800’s stone farmhouse, and we only had the render patched up a few years ago.
Maybe the wrong kind of render was used, a vapour open render such as lime would normally be suitable for a house of this age.
- We’ve insulated the ground floor with a modern insulation and now the walls of my 1700’s house are showing signs of damp near ground level.
Looks like the new insulation is not vapour open so moisture is trying to find a way out by moving up the walls.
- There is damp and mould around the edge of my window frames.
There may be a hidden gap behind the plasterboard and trim, making this part of the wall cold so condensation and mould accumulate here.
Interested in exploring more? Take a look at our video explaining the differences in traditional and modern buildings.