How to stop timber gate swelling after rain?

s321

Hi

I have recently had a post and rail fence and a pedestrian access gate built out of pine. The whole thing was stained although I'm not what the product was as it wasn't done by me.

There's a decent amount of clearance between the gate and fence - probably at least 10mm or so. But after rain the gate swells so much that it sticks and can't be opened at all. It then takes at least a week of dry weather before it shrinks back to normal size again.

I bought this product and applied another coat to the gate:

https://www.bunnings.com.au/feast-watson-250ml-swan-river-jarrah-decking-stain-250ml_p1540460

It doesn't seem to have made any difference at all. The swelling is still just as bad.

Have I used the wrong product or is there something else going on here?

What can I do to stop so much water getting into the timber when it rains?

MitchellMc

HI @s321,

What you’re dealing with is ultimately a movement issue rather than just a coating problem. Pine will always absorb moisture and expand, and if the gate is already swelling enough to jam shut, that means there simply isn’t enough clearance to accommodate that movement. While products like the Feast Watson Decking Stain help slow moisture uptake, they don’t stop it, which is why you haven’t seen any real improvement.

You could try switching to a penetrating timber oil, which tends to soak deeper into the wood fibres and better fill the pores, offering slightly improved resistance to water ingress compared to a stain. That said, even a good oil system won’t prevent expansion to the degree needed here, especially with repeated wetting from rain. Realistically, if the gate is binding, it needs to be adjusted (planed down, rehung, or repositioned) to allow for wet-weather swelling, and any coating should be seen as a secondary measure to help minimise, not eliminate, the movement.

Since this is a recent installation, you might like to contact the installer to see if they could easily adjust the gate to accommodate the swelling.

Please let me know if you have any questions.

Mitchell