Fixed Ventilation - timbers stained

[Dippy1]

Hi, I’ve been in my new build house for three years, had the loft boarded last year and noticed the timbers on one side were very wet. Turned out to be a ventilation issue because the builders had covered the soffit vents.

This has been fixed now, and the condensation has gone, but there is staining on all of the timbers on one side of house.

Is there anything I can do to remove those stains? I’m trying to sell the house but would like to not pass on the problem if it can be fixed.

 

[JohnD]

You can try Oxalic Acid wood bleach. Sold by specialist flooring and cabinetmaking suppliers. Also on ebay.

Try a test sample piece first.

It is poisonous.

Do not breathe the dust. Wipe it away with a damp rag and rinse off.

 

[Dippy1]

Thanks JohnD!

When you say rinse off, is that possible with roof timbers?

 

[JohnD]

As the wood dries, the acid crystals will leave a powder on the surface. Wipe it off and rinse the rag.

You can neutralise the acid, when finished, with bicarb. I'd wash it down with a plastic bowl and large paintbrush, catching the runoff in a bowl or old towel. There may be a better way.

When the bicarb stops fizzing, the acid is neutralised. There may be better instructions in a woodworking group. The water will raise the grain. Dry it off and, if you care, you can sand it smooth.