Case study: A cold & damp bungalow in Leeds

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The problem

The headmaster of a Leeds school contacted us about the bungalow, owned by the school and occupied by the caretaker. The bungalow was cold and suffered from damp and condensation. There was evidence of mould on some of the walls and ceilings. Although there was some cracking of the mortar on the external brickwork we felt this could be remedied by re-pointing, but there were no structural issues with the property. There were a number of smaller defects that we were able to assist with.

cavity wall insulation
cavity wall insulation restricting ventilation encourages mould
restricting ventilation encourages mould growth mould across a ceiling
A heat recovery ventilation unit of the type installed for the bungalow in Leeds

Our assessment

Our approach is to view the property as a whole, determine whether there are any structural issues and understand how the property is used and what problems the residents have.

The combination of problems in the bungalow i.e. damp walls, poor insulation, mould on walls and lack of ventilation were fairly typical of a large number of homes we visit. Homeowners often believe that damp walls mean they have rising damp or need damp proofing treatment.

Often all that is required is better insulation and more effective ventilation. Damp walls, condensation problems, and mould on walls are usually caused by warm moist air condensing on a cold external wall. Residents often assume incorrectly that the problem is caused by water being drawn up the wall from the foundations (rising damp) because of a failure of the damp proof course or because of rainwater penetrating a wall (penetrating damp).

Our solution

In this case we made a number of recommendations including:

  • Cavity wall insulation
  • Additional loft insulation
  • Heat recovery ventilation units in problem areas

Cavity wall insulation is cheap and highly effective at improving the overall efficiency of the property. Additional loft insulation gave further benefits. In the bathroom and kitchen the heat recovery ventilation units draw in fresh air which is pre-heated by the stale air being expelled.

We also specified some low and zero cost options that help preserve the integrity of the property over the longer term.

For example clearing vegetation from air bricks at the base of the external walls allows the timbers supporting the ground floor to be properly ventilated, thereby reducing the likelihood of rot, or infestation by woodworm. Likewise adding some air vents to the roof helped achieve our aim of a well ventilated and well insulated roof-space.

We don't assume that there is a single problem that requires a single (expensive) solution. Standing back and taking an overall view of the property and the way it’s lived in, allows us to recommend a number of appropriate changes. In this case the home was made warmer, fresh air was introduced, condensation problems were addressed and fuel bills lowered.