This is not an exhaustive or a complete subject. It is likely to change over time, with edits, additions and deletions, and is simply a collection of my thoughts based on many years of experience. You should follow your instincts, and you must always seek your own professional advice.
A homeowner set out to make their cellar habitable by insulating and lining the walls, but the results were disastrous. The cellar had already been properly tanked, and there was no evidence of water ingress from outside. The problem came from within.
Behind the plasterboard lining, warm indoor air met the colder surface of the tanked wall, causing condensation. Over time, this hidden moisture created the perfect conditions for dry rot to take hold behind the MDF skirting and wall lining.
When the skirting was removed, early signs of decay appeared – swollen MDF, lifting paint, and visible fungal growth. Further investigation revealed extensive dry rot spreading through the timber studwork, brickwork, and even into the floor structure above.
The retrofit had been carried out about five years earlier by a local builder, without any professional input from surveyors or retrofit specialists. The insulation and plasterboard had lowered the wall temperature, trapping moisture in a concealed void where it could not evaporate.
The lesson is clear: condensation risks must be assessed before insulating or lining basements and cellars. Even a well-tanked space can fail if vapour movement and ventilation aren’t properly managed. What began as an attempt to improve comfort ended in a costly and entirely avoidable case of decay.
We need to remember that homeowners will often be using social media for advice and tips, and looking to save costs by perhaps not using professional surveyors, architects or retrofit specialists. Conducting a proper inspection of a retrofit after the work is completed poses a high risk for the surveyor. Do not assume that just because it looks ok, that there aren’t any defects hidden from view.
Disclaimer: Anything posted in this Blog is for general information only and it is not in any way intended to provide any advice, legal or otherwise, on any general or specific matter that you can rely on. You should always seek your own legal and surveying advice.