How to weatherproof OSB for log store top

RebTech

I have a wood burner and loads of logs that need splitting and drying.

I've designed a log store and I'm not looking for comments on the design, it would take too long to explain why it is how it is. But access is via a flat top that is lifted on and off (only once or twice a month on average).

I made the mistake of choosing OSB 3 for the top, I thought that as the binder is water resistant, and after giving it a couple of coats of B&Q shed and fence paint, it would be up to the job, but after a couple of weeks I can see it's not. The paint has already flaked off in places and I suspect the board might be swelling slightly in one or two locations. Also the edge is very vulnerable to handling damage.

There's actually three of them, 2.4 x 1.2 m, costing nearly £50 in total (plus paint and time), and if possible I'd rather save the boards than replace them, but I'm thinking the existing paint might not be a good base for any better sort -- might be wrong there, not too experienced in this area. I could attach roofing felt but they're heavy enough as is. Is heavy polythene, wrapped around the long edges and attached using some sort of glue, a sensible idea? Anything else?

SailorSam

You can get that heavy blue polythene in big sheets that they use as a DPC when they lay concrete, when building houses. Would that do ?

RebTech

SailorSam wrote: »

You can get that heavy blue polythene in big sheets that they use as a DPC when they lay concrete, when building houses. Would that do ?

It might well, but the question is how to fix it? That's why I mentioned glue. I've been using tarps and the OSB was an attempt to neaten things up, anything that needs tying down takes me back where I started.

Gloomendoom

Lightweight corrugated plastic sheet?

RebTech

Gloomendoom wrote: »

Lightweight corrugated plastic sheet?

Do you mean attached to the OSB or replacing it?

Either way, the question is the same as above: how to fix it, bearing in mind it's to be regularly lifted off and on?

In fact I previously considered corrugated plastic but decided that to be robust enough it would have to be on a relatively heavy frame, also for 2.4x1.2m more than one sheet would be needed, therefore overlapping, etc, etc. Also, it has to be fixed at the peaks, not the troughs, so can't be directly attached to sheet materials such as the OSB, and any subframe would make the whole far too heavy.

I'm still inclined to think that proofing the OSB is probably the best idea, using some kind of coating or thin flexible sheet material such as polythene, but what coating, or how to attach the sheet?

Gloomendoom

RebTech wrote: »

Do you mean attached to the OSB or replacing it?

Either way, the question is the same as above: how to fix it, bearing in mind it's to be regularly lifted off and on?

I replaced the felt on my shed roof with it. It's nailed into the OSB roof board underneath through the peaks using miniature roofing nails. I did paint the board with exterior gloss before I covered it.

You would probably need to take care with the lifting though. It would be easy to catch an edge and crack it.

Otherwise I would suggest bitumen paint... and gloves for when you lift the boards off.

blackshirtuk

How about fibre glassing it? , may be a little expensive but looks good and will last forever

RebTech

Gloomendoom wrote: »

I replaced the felt on my shed roof with it. It's nailed into the OSB roof board underneath through the peaks using miniature roofing nails. I did paint the board with exterior gloss before I covered it.

You would probably need to take care with the lifting though. It would be easy to catch an edge and crack it.

Otherwise I would suggest bitumen paint... and gloves for when you lift the boards off.

Don't know about roofing nails, is it just that these are long enough to reach from the peaks to the board?

I suspect bitumen paint might be the most practical option, but will it adhere to the existing shed&fence paint or would that have to be removed? I know, really should have researched this properly before starting.

RebTech

blackshirtuk wrote: »

How about fibre glassing it? , may be a little expensive but looks good and will last forever

Nice idea in principle. As the glass is for structural strength would I get away with ditching it and just painting the resin onto the OSB?

RebTech

Think I might be snookered for bitumen paint or the like by the fact that the current paint is water repellent.

Stooby2

I've done my garage roof with a rubber sheet that is glued to the wood. I got it all from Rubbaseal but other companies might do it.