I've just laid 18mm loft flooring boards in the garage loft. They're made from that compressed woodchip stuff (I'm sure it has a name). From past experience with this material, any moisture/wetness makes it swell up and crumble to pieces.

So what is the best thing to paint them with to prevent them from doing so? Obviously painting them with water based paint might just make it swell rather than do any good, so any ideas?

PVA? But then do I have the problem of having to water it down which in turn would screw up the board?


Forgot to mention, it has to be proper locost, otherwise I'll just leave it and replace them if/when any swell up (£5 for 3 boards).


Cheers,
Pavs

You want things like thompson water seal. Even varnish would seal them.

linseed oil.

If they are inside why would you want to seal them?

Because they're the flooring of my lofted space in the garage, which inevitably is slightly humid, but more importantly bits that I store up there might have drops of water on them when I put them up there. And I know from past experience that it doesn't take a lot of water to make these things swell up.

So I just wanted a protective layer to make them a bit more durable.

Cheers all

Varnish gets my vote, even thin it so it soaks in well.
I reckon any oil paint you have kicking about would be alright too, again thin it (quite a lot) so it soaks in a bit, otherwise it just forms a layer and won't bond well. Make sure you get the edges, thats where problems often start.

You can get water-based varnish now, for indoor use. It goes a long way, is easy to apply and dries quickly (~30 minutes between coats). You can wash the brushes out in water too!

I used it on some shelves, and it's proved to be very durable.

true locost = any old paint, they'll be out of sight and so all the colours you have, your mates have and any found elsewhere wont matter,....

hth

Would a trade 10l tub of white wall paint work fine? Got some leftover kicking about the garage!

If not I'll get some waterbased varnish.

Thanks all,

pavs

PVA glue

its cheap

I personaly would'nt bother as i can't see the moisture building up that much in a garage loft unless your heating it through the winter which might cause condensation problem's then you would be looking to get it properly ventilated.

You could paint it with watered down PVA which would'nt effect the board but you would have to do both sides but i see you have already layed them.PVA is used to join the boards together while screwing them down.If it is Caberfloor board's then i definatley would'nt bother as they are probably one of the better manufaturer's.

I'm in the building industry and seen some boards taking a bit of soaking with no effect's.

i too would say dont paint it. It should be moisture resistant chipboard. If you create a waterproof layer on top, then any condensation that forms underneath will be unable to evapourate out. Your loft will not see much water. Focus more on stopping air getting into it from the house, as this is a major source of condensation. Keep it ventilated, and keep an eye out for missing tiles etc.