Paint separation between weatherboards

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AklBen

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#280840 14-Jan-2021 10:08

About this time last year we stripped and repainted our weatherboards. 2 coats of primer, 2 coats of top coat. Now, as the house has settled, dried, gone through the seasons some of the weatherboards have naturally separated and has split the paint with it in the gap/join. It's resulted in a bit of a ridge of paint where the join used to be and part of the bare weatherboard being exposed (very small 1-3mm section).

Is the best remedy for this just to scrape, sand the ridge and repaint with the top coat? Ideally I don't want to be doing this every year...is the a way to do this in a better way? E.g. only paint the weatherboard and try not to paint the gap?

timmmay

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#2635244 14-Jan-2021 10:24

I've had this happen too. I just scrape off any excess paint if it's enough to bother me in high traffic locations (might not bother if it's underneath the ridge or round the back), fill gaps with no more gaps exterior weatherboard as it's flexible (giving it a full day to dry even if it says 20 minutes), prime, then paint two coats. If you use oil based primer than at least 24 hours for no more gaps to dry, 48 hours is better.

You usually only do one coat of primer, just FYI. Not really relevant to this.

AklBen

102 posts

Master Geek

#2635250 14-Jan-2021 10:31

^ thanks.

Yes I did wonder about only doing this in noticeable spots and just leaving the rest.

timmmay

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#2635308 14-Jan-2021 11:00

Not all weatherboards will separate, so I'd only do it where required. I guess it happens where there's more expansion, like hot areas, and maybe areas where it's not nailed on as well? Just guessing really.

frankv

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#2635460 14-Jan-2021 14:12

^ Yeah, north-facing walls get more sun and heat up more. (Also more sun means paint on north-facing walls deteriorates faster). But the whole house structure can bend and twist. In extreme cases doors may not fit into doorframes or window glass can break. Darker colours cause more heating in the daytime, and more cooling at night, so larger and faster temperature changes.

Personally, I wouldn't worry about that strip of wood showing. It's under the "eave" of the next weatherboard, and only exposed in the summer, so (unless you're in the tropics) won't get much (if any) water. If you do paint it, it'll probably get scraped off and added to the ridge when the house shifts back into it's winter position. More layers of paint make that more likely. Maybe put a single layer of topcoat on, just for aesthetics. Of course, if you do paint it, the house will shift more in the next month as it gets hotter, and you'll have another 1-3mm strip to paint. So, to fix this, you really need to be out there painting in the maximum heat of summer, say late February. Enjoy!