So how do you know your damp is caused by cavity fill and simply not down to a lack of ventilation? Here are a few tips to help you diagnose your damp problem.

Damp on walls is much more noticeable as it presents itself on the internal wall causing the plaster/wallpaper to bubble and the plaster will crumble as the moisture in the wall rises. There can be a number of causes for Mould on wall caused by recent storms:

The cavity wall insulation may have been damaged during flooding. And the winter of 2013/2014 has caused major problems for the insulation installed in cavity walls.

The property being located in a high exposure area, to wind driven rain. Cavity wall insulation should not have been installed in the first place where the property is in a high exposure zone.


Condensation often presents itself on cavity walls; around windows and more often in the top and bottom corners of rooms as black mould and is caused by warm air inside the house condensing on cold wall areas. If cavity walls are filled properly at point of install, to the correct density you should not be experiencing this problem, however there is a growing amount of cases which are coming to light, due to poor workmanship.

Some early forms of cavity wall insulation was installed in the early 80’s, this would have generally been Urea Formaldehyde foam. This particular insulation deteriorates over a period of time causing voids in the cavities; thus causing condensation on the internal walls.

Unfortunately now we come across many more cases of poorly installed cavity wall insulation due to poor workmanship, for example the wrong drill pattern has been used or density which the insulation has been blown into the cavities has left voids which may also lead to condensation. Installers should be performing a box density check (for fibre installs or flow check for bead insulation) a daily record should be kept of this. Two examples of this are Whitewool should be .9 Rockwool should be 1.3.

In cases of condensation and/or damp the best course of action is likely to be removing the cavity wall insulation, but firstly contact us to arrange a survey, or visit our web page for more information on what we can do: cavity wall insulation extraction.

Do you want to know more about the CostsProblems or the process on how we do it?

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