Moisture levels in structural timber

I have a Victorian terrace house with a nice cellar. When I bought the house the surveyor said the timbers in the cellar were a bit damp and I should ventilate the cellar to let them dry out. Over the years I have fixed a drainage issue which occasionally let water into a corner of the cellar and a bit at the front of the house which did the same.

The cellar window has been open for years as advised but it makes the cellar and the kitchen above very cold in winter and the dryer hose was poking out of the window which was a bit shoddy. The window was also rotten from being half underground in the cellar well and being of poor quality.

I recently put a new window in the cellar which I made myself out of pressure treated timber. All sealed up ok with a proper vent in it to let some air in/out, but obviously not as much as an open window which the new window doesn’t have.

I am a bit paranoid that the wood beams in the cellar will now get damp (despite me knowing I’ve stopped the water ingress) so I’ve bought a moisture meter to keep an eye on things. Only a cheap one but it’s better than nothing and it’ll help me track changes at the very least.

So what %age moisture is ok? Any ideas or any other thoughts? I don’t want my cellar ceiling collapsing really. Will the wood just get damp anyway even if there is no visible water ingress? The cellar does have heating to keep off the chill – plumbed into central heating.

20% when you buy Structural timber eg C16 etc

http://www.mbmfp.co.uk/graded_carcassing.php

If you’re not sleeping in there a dehumidifier is a relatively cheap insurance/peace of mind solution?

If you are sure there is no more damp coming in, I would use a dehumidifier. Expect to run it for a year, at least, to suck out the residual moisture.

I had exactly the same from a surveyor who said moisture levels were approaching that needed to support dry rot. On his recommendation I simply re-opened the coal hole and fitted a grille brick. Within a very short space of time the cellar smelled and felt considerably less damp.

The window has been opem for 10+ years and nothing smells damp at all, and no visible signs now as the fixes I did were a while ago. Cellar now has an air brick and the vent I put in which is about 25x25cm.