Wood expanding when wet

Kweegly

Hi Everyone,

I built some gates for the side off my house and with the rain today the wood expanded and started to squeeze the glue from the joints. The gates had been drying indoors for a week to ensure the glue had set solid.

Is this normal or when the wood dries out will there be gaps where the glue has been pushed out?

I'm hoping the glue will flex with the wood, is this the case?

 

Thanks in advance

Kweegly

pictures for reference

 

 

Steve 309

Hmmmm

I think you need to dry it all out again, use waterproof glue and then seal it with several coats of varnish or paint to keep the water out.  It's partly for this reason that exterior woodwork is not normally glued - better to use nails, which will allow some movement as the moisture content changes.

Kweegly

Damn! I thought I was being all clever using mortise and tenden joints

I didn't get around to treating it yet as I wasn't sure what to use for a good look and also good protection.

Kweegly

Thanks, I was thinking a varnish to bring out the grain. I'm hoping when they dry out I can treat them without having to rebuild it all!

Katherine W

Cascamite is a great glue for outdor woodwork (better than nails... when the wood is very dry in summer nails can easily pull out).

me london

I wouldn't use varnish, it will probably peel off in a few years and will be a headache to maintain as they do not really penetrate the wood, more create a film.  Also, it's hard to get varnish that isn't water-based now, and water based isn't really that good for outdoor use in my experience.  I'd use something that is designed for fences, proper outdoor wood treatment - any wood preserver will do the job well, oils are good too.

Kweegly

Thanks for the advise

Jolly Gary the Gardener

I agree with all the above, I have used Cuprinol wood stain on fences and my summer house its great and the water beads off when its raining. Apart from water causing the swelling  the ambient temperature can cause problems as in hot weather  the wood can shrink back but in cooler weather it will expand even if you use wood stain but if the wood is stained it will usually expand with the wood so maintaining the protection.

In the past I have used B&Q fence preserver and it is not bad but wont last as long as some of the more expensive preservers

Regards

Jolly Gary

JBDRINA

I agree with 'blighty man'. Varnish isn't very good for protection and will be a pain to sort out in the future when a re-coat is required. How about Sadolin wood stain. If you start with the thin (green tin) stuff and apply a couple of coats of that it'll soak into the wood quite well. You can then finish off with the thicker (yellow tin) as a top coat. If the gates are in full sun then thin the top coat 30% with the thinner coat. It'll help to stop it cracking when the wood moves. This worked very well on the front of my house for a number of years and applying further coats is quite easy. Preparation is basically washing down rather than removing the old coats. 

Potteringabout

Before you apply any preserver you will have to dry out the gates thoroughly. If you wanted to apply a varnish then a yacht varnish would be the best bet. Ronseal do a good one. If you apply a varnish, or any other sealer type treatment, without completely drying the wood you will be sealing the water in which will lead to them rotting. You will find that the wood will contract when it dries and may cause the joints to become loose or the gates may warp. 

I'm sorry to sound all doom and gloom and I hope you are lucky and they are fine. If not then we all make mistakes, the secret is to learn from them. Good luck.