White mould on stored oak planks

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SteveB71

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Hi all, im a complete newbie when it comes to wood, I found some cheap 3m oak planks which i want to use on the outside of a steam room. They are stored in a dry garage, they have White mould on them! What’s the best way to treat this, I’ve read bleach will not sink in and that a vinegar solution sprayed on would give better results. Will this completely cure the problem? Thanks.
 
If you work with metal, it maybe worth considering that it might be possible that your oak might react with the vinegar and stain it black.
I wonder what would happen if the old school woodworm preventative of borax powder
was applied?
Just asking, and in no way a suggestion.
Would be a two birds solution if it worked?

Thanks
Tom
 
Picture would be interesting to see how serious the problem is. Probably just wiping the mould with a bleach solution would be enough. It's unlikely to be anything damaging to the wood. Sounds like it is just surface mould, so bleach should do the job. You can get mould killers, but I would try bleach solution first.
 
You can also kill mould with methylated spirits. It's not acidic, so no danger of a reaction with the tannins in the wood. Also dries more quickly, which is handy.
 
As others have said if its just a light dusting it will wipe off with light application of soap and water, or a light bleach solution. (although vinegar is great at killing moulds and fungus - its used in most environmentally friendly patio cleaners - it's acidy reacts with metals and can discolour woods so best to avoid for now) If you are quite new to woodworking, I'd suggest you get good projection from breathing the oak dust, depending if you use hand or power tools, mould spores and Oak dust are probably the biggest hazards to watch out for. A good mask eg https://smile.amazon.co.uk/gp/product/B004YVYBX8/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1and if you can some form of vacuum extract on power tools and the usual PPE. Welcome to the forum and good luck.
 
Thank you all for the input, here are a couple of pics. Some boards are worse than others, some have none etc. I originally scraped it off as I had no idea what it was but it has returned with a vengeance! There are 32 3m boards in total and I’m unsure as to the extent of progress, but after seeing the top one get so bad I started to worry what effects or problems it could cause.
 

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looks like a large slice of brie. are you stacking boards without a spacer between?
 
Sorry, I cannot remember the actual species of fungus you have. But it has clearly invaded the top surface of the wood and I think you can see some staining. I do not think it will decrease the structural integrity of the timber once dried out properly but the stain will be difficult if not impossible to remove, although you may get some benefit by removing maybe 1mm. Can you kill it for good? Maybe not. I think drying the timber properly will stop it.
Cheers, Phil
 
If its going to be used for exterier cladding than I think I would give it a good scrub with bleach and hope that being outside in the air would prevent its return,,,I think, and I might be wrong, but nearly all mould thrives on damp still air, the mould you've got looks like the stuff Ive seen under old suspended floors?
Steve.
 
Sorry, I cannot remember the actual species of fungus you have. But it has clearly invaded the top surface of the wood and I think you can see some staining. I do not think it will decrease the structural integrity of the timber once dried out properly but the stain will be difficult if not impossible to remove, although you may get some benefit by removing maybe 1mm. Can you kill it for good? Maybe not. I think drying the timber properly will stop it.
Cheers, Phil
Thanks Phil, I’m not too bothered about the staining, I am bothered about it returning, especially after I have built my project! More so if I can’t see it, would a sealant of some description stop it in its tracks?
 
If its going to be used for exterier cladding than I think I would give it a good scrub with bleach and hope that being outside in the air would prevent its return,,,I think, and I might be wrong, but nearly all mould thrives on damp still air, the mould you've got looks like the stuff Ive seen under old suspended floors?
Steve.
Thanks Steve, would you have any thoughts on a sealant I could use, it will be used for exterior cladding so will definitely come into contact with all types of weather. Hopefully April will be sunny and dry and I can clean, sand, dry completely and possibly coat with something...
 
When air drying timber it is highly recommended to insert stickers under every board in the stack to encourage free flow throughout the stack. Whether its inside or out, heated or not. Stacking planks that haven't dried on top of each other is just asking for problems.
 
Thanks Steve, would you have any thoughts on a sealant I could use, it will be used for exterior cladding so will definitely come into contact with all types of weather. Hopefully April will be sunny and dry and I can clean, sand, dry completely and possibly coat with something...
Im not really the best person to ask, oak just weathers outside and becomes grey, the wood has lots of quite powerful tannins in it and just speaking personally I would of course clean off the mould, using a bit of bleach and then as its going to be outside cladding just use it, again its just my personal opinion but I would think its very unlikely to be a problem. The little bit of oak Ive worked with has always been left untreated so dont know about applying a finish. Im sure there will be someone on here that knows for sure,,
Steve
 
The wood looks quite damp. Definitely wash with dilute bleach and then dry thoroughly. It could be Laetiporus sulphureus, its a bracket fungus that attacks oak trees. It needs upot 30% moisture to thrive, so a good airing should stop it. If the oak is outside on a vertical face is should be fine. If its on a horizontal face then you may have damp problems. You could try a teak oil finish, but that will probably not weather that well. If you dry the wood well its should just go light grey in the sun. Keep it away from water to keep the mould at bay. Good luck Tom
 
Thanks everyone, I shall sticker them all, wait for some warm dry weather and use a bleach solution to clean.
 
Brush off what you can. Mix one part bleach with 4 parts water and wipe on. Leave 48hrs, rinse off and then repeat. You need the second application. I would not apply any surface finish. As others have said the timber is damp with insufficient air circulation and hence the mould. When dry the problem should go. Eventually you will have some lovely grey weathered oak.

Colin
 
Brush off what you can. Mix one part bleach with 4 parts water and wipe on. Leave 48hrs, rinse off and then repeat. You need the second application. I would not apply any surface finish. As others have said the timber is damp with insufficient air circulation and hence the mould. When dry the problem should go. Eventually you will have some lovely grey weathered oak.

Colin
Many thanks Colin. Will do. I initially thought oh dung, wtf is that, that’s why it was £5 a length lol can’t wait to use it, going to be a great project.
 
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