Thread: New Weatherboards oozing sap?

Well Dombat as everyone else is too scared, I'll give it a go.

shrinkage, 2-3 months, where you are if you can see the sun, this is normal. Sun hitting a vertical surface, will dry your boards out. Also doubt they would have been kiln dried or anything similar before buying them?

Sap, timber is a natural product, sap is part of the timber, you'll be able to stop it by using fibre cement weather boards

It's just timber mate, sorry

Dombat,

A couple of things come to mind:

1. I'd hazard a guess the timber was not well seasoned or kiln dried before it went up hence the oozing sap. In the old days - and I am an old bloke - we used to use Silverfrost [an aluminium finish paint] to spot prime any suspicious ares to help prevent this bleeding
2. You mentioned bubbles, could be an extenison of 1 or the timber was painted over when it was damp. If the paint was acrylic you are getting water vapour being trapped between the timber and the paint - hence the bubbles

To me the fix is not easy. All the bubbles and bleeds will have to be sanded back to bare timber and I'd be inclined to let them sit for 2 weeks or so. Spot prime the bleeds with aluminium paint. Paint the rest as normal.Where there is shrinkage use an exterior gap filler

That's about my spin.........good luck

Dombat - the 'sap' that is oozing from your weatherboards is pitch or resin, which pines & their relatives make in response to various forms of injury - some species moreso than others. From my experience, there is nothing that reliably 'seals' it in, it keeps on oozing out in warm weather until the volatile solvents disappear & it eventually hardens. Probably only take a few good hot summers, in your neck of the woods. Pitch can be 'set' by heating to 70 degrees C for a couple of days, but I don't think it's all that commonly done, judging by the number of oozing resin pockets one encounters in construction grade softwoods. You could try holding a heat gun against each bleeding point for a few hours.

Even if your wood had been kilned, I believe softwoods are only dried to about 20% MC. There is probably little point in going much drier for most applications - the way wood is treated on the average building-site means a good deal of it is rained on & returned to pretty high moisture levels before it gets any protection from the elements (I well remember watching my kilned hardwood framing being rained on day after day in an extension we were having built through the wettest 3 months in 15 years! ). So experiencing some significant shrinkage after fixing is hardly surprising, on many jobs. With luck, your weatherboards have been properly attached, and the shrinkage won't stress the fixings, so the worst you face on that score is a bit of repainting of the exposed bits.

My 2c,
Cheers,

hello dombat, there a few isues going on here, some have already been coverd. you dont mention what colour its been painted? if its a dark colour this will make the sap bleeding worse. to treat the area you can expose the area's and let nature run its course!! or you can expose the areas and clean them with meths then heat them up with an electric heat gun until all the sap has run out. you can drill out any small areas and repair them with epoxy resin or similar.
to re-paint -- expose wood-clean of with meths- spot prime with alliminum wood primer- paint as normal.
hope this helps