movement

[marcros]

All things being equal, what is the rough working guide for how much wood may expand between its minimum and maximum sizes, say over a 500mm board? the timber will be acclimatised to the indoor conditions prior to being used.

I have an elm project, and an oak one coming up. Both have a cross grain situation, where I will fix it firmly in the middle of the board, but I don't know whether putting the ends in a slightly oversized hole will be enough. Even if I use table buttons, I don't know how much gap is enough.

 

[Droogs]

It's hard to give definitive figures as a narrow piece will move more than a wide board

 

[dzj]

If it will be in a climate controlled environment, then very little.
If it's going to be exposed to the full seasonal change of humidity, depending where you live and whether it's QS or FS,
your 500mm Oak board could expand anywhere from 2-10mm.

 

[Glynne]

I’m currently in a similar position in making a keepsake chest where the sides have the grain running vertically rather than horizontally.
I had a search for “Wood movement calculator “ and came up with several sites including Calculator
As dzj said, in a controlled environment very little - I think for me it was ~1mm so probably acclimatise your wood as much as possible before assembling.