Should we treat our oak beams?

Very few old buildings have never had some form of infestation — generally woodworm prefer the softer and sugar-rich sapwood which is the outer layer of the original tree (usually avoided, where possible, by carpenters).

Both woodworm and the various timber rots depend to a great extent on damp and cool conditions — the most vulnerable areas being the timbers built into the walls. Assuming that your barn is warm and dry, there is little risk of attack.

Any treatment applied now will be a toxic brew of chemicals — killing useful spiders and potentially causing health problems to the building’s occupants whilst losing any efficacy before being required to treat an attack of woodworm. Therefore, it is far better to monitor the timbers for any new flight holes, evident by a fine dust within or deposited underneath.

Giving a sheen to your timbers might seem attractive from a modern perspective, but traditionally structural oak timbers were left untreated. Should such a finish be considered essential, avoid modern concoctions and beware of repeated applications of linseed oil which will not only darken your wood, but can leave it sticky. Beeswax polish could be used on smooth timbers, but it’s hard work.