I have a pallet load of redwood (dressed) various board sizes but
approximately 150mm x 25mm x 3M each. I had them stored outside under two
tarpaulins (cheap B&Q ones). Obviously not really up to scratch for this
purpose and I have only uncovered them to find that the damp/wet has got in
and a number of them are covered in the black/grey mould (or whatever?).
It's not thick at all in fact it seems more like it has stained the wood
rather than coated it. This lot cost quite a bit to buy so I want to salvage
as much as possible.
Does anybody know of a cleaner that will get rid of this or suggest what is
the best course of action to remedy the problem.
Ideally it should be stacked with spacers to allow air circulation and
sheltered from rain but with the sides open.
Household bleach will kill the mildew, but it will go anyway once you
have the right conditions.
It will dry outside as long as rain doesn't fall on it. Re-stack it with
2 *sticks crossways between each layer. Cover with tarpaulin but leave
the ends open. That way the air can blow along the length.
Any concentration of hypochlorite bleach will do (10% in water?) but I
wouldn't bother if the air circulation is improved. It would be a lot of
work and introduce a lot of extra water.
*for stick read anything you have two of that are the same thickness.
Put them a third of the way along, not at the ends.
Blimey, isn't it difficult explaining simple things?
It is important to determine what is the target organism.
It is likely to be one of two - a soft rot STAINER wood-destroying
precursor fungus which produces soft rot cavities and goes in at 90
degrees to the grain of the wood (the trachaeids)
Aspergillus niger a MOULD which leaves black growths over the surface
On balance under those conditions I suspect the former but you would
have to get a microtome and take sections to find out!
What to do
The staining per se is not a problem unless you intend to varnish it
as once it is dry it will die and you can paint it
If it is a mould you can dry it and simply brush it off.
Any "pesticide" or "biocide" should be used only for the purpose
intended and targetted to the organism - there are lots of laws CPRegs
COSHH etc which stipulate how to and not to do this. Bleach per se I
do not think would be appropriate but might work once you have dried
it out. I have this vauge memory that oxalic acid (VERY poisonous) is
quite good but you need to check this out.
I also suspect a good dose of UV light would have a desirable effect.
Others have advised (correctly) how to store
Personally I would get some corrugated plastic over the top and leave
at least one side free and open if it had to be outside or try my
best to find a place inside.
If it is to be floorboards and not painted then do leave them inside
for a long while to shrink down before you lay them or you will get gi-
normous gaps after a few months of CH