Due to various poor decisions by previous owners, the subfloor of my house has been damp and inadequately ventilated for many years. I've restored the ventilation but will have to repair/replace several rotten joists. Of the joists that are not rotten, some have quite high moisture content when tested with a metre. My understanding is <12% is ideal and >15% is when one should be concerned. I am hoping that they will dry out now that the subfloor is ventilated, but I really don't want to risk further issues later on. Is there, in anyone's experience, a moisture content above which it's better to replace a joist anyway, even if no rot/woodworm is currently evident?
Joist moisture content
- Thread starter presdiy
- Start date
Those readings are very generic, and for internal timber.
You will also be probing the surface, which will give higher readings
Timbers in a ventilated floor void will be subject to the humidity of the air coming in and evaporation of damp substructure, and acceptable percentage will be variable and up to the low 20s
That's reassuring thanks, I'll focus on the rotten ones and leave any precautionary work to the ones with higher readings.
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