Mould growth on timber

[cowboy25]

Hi I have some ply wood boards stored in my workshop I am going to use for the floor on my shepherds hut however the boards seem to developed mould on any surfaces exposed to the air. I had six of them standing upright and the ones in the middle seems to be ok. This has thrown a spanner in the works. I have removed the mould using either a belt sander or wire brush, but is the wood ok to use now? Should I apply some sort of mould killer? And should I then protect the wood with tung oil or varnish or something prior to using it for construction? I don't want everything moulding once the hut is made and standing out in the field.

 

Nb I'm quite surprised about this mould growth as no other timber in my workshop has mould on it, it's only the ply wood boards 

[JohnMo]

Give them a wash over with diluted bleach, to kill the mould spours.

[MikeGrahamT21]

Bleach doesn’t kill mould in any way it just hides it by bleaching the visible bits. Use proprietary mould killer to get rid of it permanently.

 

Hope you had a mask on when you were sanding/scrubbing as it can end up in your lungs and cause aspergillosis, not pleasant at all. Ensure the boards are as dry as possible once treated, then sealing them will help reduce uptake of moisture, but be careful what you choose to use, as it could interact with the glue in the ply causing it to delaminate, I’m sure there will be a purpose made product for plywood sealing.

[cowboy25]

I bleached washed them after sanding/ wire brushing and then I used a proper mould killer as pictured. I used a mask when applying teh mould killer but not whikle sanding however I was standing next my open workshop door whilst sanding so I had access to fresh air but duly noted for the future re masks and sanding.

 

[cowboy25]

 

The mould is back on 2 out of the 5 plywood boards to be used as the sub floor of the shepherds hut. Ffs. How much of problem could this be does anyone know?? Can I just scrub it off and start building or do I need to buy more mould remover? Too many setbacks here, can anyone recommend a good mould remover apparently the I used wasn't up to the job.

Edited Monday at 20:05 by cowboy25

[Mr Punter]

I have found plywood to be a great home for mould, especially outside or in damp conditions.

Edited Monday at 20:52 by Mr Punter

[cowboy25]

42 minutes ago, Mr Punter said:

I have found plywood to be a great home for mould, especially outside or in damp conditions.

Is OSB board more resistant I wonder? Whats the answer here, I wasn't expecting this problem, no other wood in my workshop (oak flooring, tongue and groove softwood cladding, oak doors, 2x4 baton etc) is experiencing this problem.

[Mr Punter]

Yes I think OSB with a coat of solvent based varnish would work well.  Apply to the edges as well.

[Alan Ambrose]

I have this problem too, curiously on better grade ply rather than the cheap stuff which seems fine.