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.
Although the impact of beetles in historic buildings is widely discussed, there is less information available about the impact of moths.
Moths can be associated with wool insulation. This type of thermal insulation is used because of its ecological benefits. However, there are some reported cases of it also being a perfect habitat for moths. Some moths are shown in the photos here.
There is a difference of opinion of whether the wool should be pre-treated or not. If you intend to use this type of insulation on your project then do keep it mind and make your own enquiries.
In cases where there is a severe infestation it seems, based on the experience of others who have had to deal with it, that the only option is to remove the affected material and thoroughly vacuum the area. The costs can be very high and the disruption to family life can be intrusive.
Moths can also affect wool carpets, furniture, clothes, curtains and other fabrics. It may be necessary to remove and dispose of these finishes. The cost of replacing wool carpets is likely to be high. The larvae will be within the carpet weave and can be hard to remove.
The moths like dark, cooler habitats and can be hard to locate initially until it reaches the stage of being an infestation. For example, they might be found under beds, in cupboards and wardrobes, behind (or within) curtains that are used infrequently. Where wool insulation is used, this will almost always in dark undisturbed places such as a roof void or concealed under floors.
Update: February 2025
The following news story hit the headlines and is worth a read. The legal judgement can be found on the High Court website and has been widely publicised.
Couple can hand back moth-infested house
While the headline for story is about moths, the sums of money involved is extreme. The consequences of this case go much wider than might initially be recognised.
The case sets a clear legal precedent about sellers being honest and transparent and must not be misleading in replies or holdback known information. It also emphasises the importance for buyers to be cautious when viewing properties that have been altered and refurbished. It further emphasises the need for surveyors to be cautious and to consider risk and not simply condition.
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.
