Thread: Wood shrinking

The timber needs to be glued together so the whole top will move as one. Commercial furniture moves as well - most mass produced stuff is MDF/Plywood/Particleboard/honeycomb paper construction so movement is much less of an issue. But the solid timber stuff will move. The effects are minimized by how the furniture is built (eg frame and panel) or just ignored.

Edit: As for how you can stop it moving in future, you can't. Laminating the boards together will allow the whole table top to move as one but if the joinery isn't correct, you could end up with boards splitting as they're unable to move. Come summer you'll find the gaps between your boards disappear as they expand due to the humidity.

Thanks for your help. I will keep an eye on the table, see how the wood changes.

Ive done some research and can see how I assembled it wrong. I glued the table boards onto the box frame the legs are part of. So the wood cant really move much except away from each board.

David

Welcome to the Forum, David.

Twenty five years ago I built a small deck from treated pine and the local council insisted that I space the boards 6.35mm apart - yep, they quoted two decimal places, and they sent around an inspector to verify that I had complied! The timber shrank and the gaps are now up to 20mm wide.

Deck.JPG

Timber will expand and shrink with changes in moisture or humidity. You just have to learn how to live with it; you cannot fight it. Good design allows for this movement; poor design falls apart.

Different timbers move at different rates. These are quantified in standard references such as:

• Keith Bootles, Wood in Australia, McGraw-Hill, and
• the online Wood Database - The Wood Database

Just keep reading about how to deal with wood movement. And look closely at furniture to see what techniques have been used. For example, with table tops there are several attachment methods that allow the wood to slide a little to cope with movement.

As other have said, you can't prevent wood movement. But you can adopt strategies to minimise the effects.

Apart from proper design to accommodate movement (lots of info on these forums & elsewhere on this topic), you should allow the timber to acclimate before you begin construction.

Ideally, let the wood sit in an environment that is the same (or as close to same as possible) as the final destination that the piece will be living in PRIOR to construction.

Minimum time to acclimate for already well seasoned timber would be 3 - 4 weeks, but the longer the better.

So, for example - don't build something in a shed that is hot and humid, then move it into an air conditioned home and expect it to remain stable. The wood will move.

Alternatively (if you have not got a controlled environment in the shed - many don't) acclimate the wood in the final destination, e.g. in the house, then mill & construct it very quickly in the shed, and move it back into the final destination as soon as possible, and also between processes.
For example, you could:
1. mill the timber in shed on the weekend, then move timber into the house during the week.
2. Next weekend cut joinery & dry assemble, then move it back into house.
3. The following weekend glue up in shed, then move into house to dry.
4. Final weekend, move it to shed to apply finish, then move it back into house ASAP.