Hello,
I am building 2 Bath Vanities out of White Oak, I suppose design wise it would lean more towards "furniture" style than a traditional cabinet for a visual.

There are 4 legs 1.75 x 1.75 with a top rail and bottom rail about 18" from the top. The sides will have a solid White Oak panel 1/2"+ thick ~18" x 18". Between these two rails, the panel will will be flush with the legs and the rails with a reveal 1/8" to 1/4" around the edges to create a shadow line. I would like it to be as minimal as possible but am worried about expansion. Looks like White Oak has the possibility of expanding quite a bit, I don't know the change in MC from Winter to summer in my area so I just took a guess at 4MC which when plugged into the calculator gives me something like .26xx - Am I looking at this the right way?

The other question is how to best keep the panel centered, I was thinking of using space balls but now think it may be better to just pin it in the center top bottom inside rail and maybe just space balls on the bottom top to help with any rattle. thinking this may be the best way to have any chance of the panel expanding equally right/left so the reveals stay somewhat even.

Hopefully I explained it clear enough, any feedback/recommendation would be greatly appreciated.

Here is a screen shot for a better idea. It is showing a 1/4” reveal, I would like to do 1/8” - 3/16” but idk…

View higher quality, full size image (2388 X 1668)

I haven't done the calculations to double check the the answer but it sounds about right. You could halve the movement by selecting quartered or rift cut oak.
With respect to keeping the panel centered, you can pin the panel tongue top and bottom in the centre from inside the cabinet.
The down side of a frame and panel here is that any water drip down the side could collect in the groove at the bottom of the panel and discolour the wood.

You are overthinking this too much about wood shrinkage. You can't predict wood with a calculator; if the bathroom has a shower, all bets are off the steam will keep the wood stable.

What I know is I've worked on 70 years white oak doors exterior doors 3 inches thick in Montreal, which means coldest arctic winter steaming hot summers there was no line.

I've installed a lot of doors. I'm in probably the worst designed houses in North America, meaning no thought of house humidity, just dry electric heat till June. Made doors, bought doors never any callbacks for lines. Also lots of doors on BOATS.

Seen customers blame me when there 2 by 4 shrinks in new construction and I went to the ceiling and there was a gap because of the shrinkage.

I hope you don't show the customer the calculation it won't show your smart just something for the customer to worry about and ammunition if they don't like something down the road
The drawing looks great

Thanks, unfortunately i have the side panels resawn out of flat sawn already, do you think that if i allow 1/8” deeper slot that would be enough for the movement or should i go 1/4”?

Good point on the lower rail, I didn’t think of that

I disagree that you can’t predict wood expansion, you most certainly can “predict” shrinkage/expansion of wood. How good your prediction is depends on the amount of information one has but that’s a different discussion.

You are probably correct that I am over thinking this but I am not really loosing sleep over it, just looking for feedback from others who have more experience with this than I do, typically I do panels like these in laid up in veneer so I have never really thought about it.

I also realized last night as you pointed out that because in the bath it may be more stable and won’t see that much expansion/shrinkage anyways.

I am mostly concerned with the reveal staying consistent I am absolutely not concerned about the construction method.

So maybe I listed too much info and the question should have been something like:

- I have a frame and panel, the panel has a 3/16” reveal on all 4 sides of the panel. I want the reveals to stay consistent through seasonal movement if any occurs. If i pin the panel in the center will the panel expand/contract evenly so that the reveal remain the same?

Why in the world would anyone share that info with the customer? I would simply say, sorry it can’t be done, plus my customers already know I am smart :)

There's no harm in working a deeper dado. Apply one or two coats of finish to the panels and frame grooves before assembly to seal them. This will help with any water that might get caught in the groove.
Hey Kevin, I'm just down the road in Ottawa. In my experience, most of the wood movement problems I see are in the first year. I have been seen plenty of panelled doors that are showing off unfinished edges due to shrinkage. I'm sure a walk around your neighbourhood would show you an old door or two with a split in the lower rail.

I disagree that you can’t predict wood expansion, you most certainly can “predict” shrinkage/expansion of wood. How good your prediction is depends on the amount of information one has but that’s a different discussion.

You are probably correct that I am over thinking this but I am not really loosing sleep over it, just looking for feedback from others who have more experience with this than I do, typically I do panels like these in laid up in veneer so I have never really thought about it.

I also realized last night as you pointed out that because in the bath it may be more stable and won’t see that much expansion/shrinkage anyways.

I am mostly concerned with the reveal staying consistent I am absolutely not concerned about the construction method.

So maybe I listed too much info and the question should have been something like:

- I have a frame and panel, the panel has a 3/16” reveal on all 4 sides of the panel. I want the reveals to stay consistent through seasonal movement if any occurs. If i pin the panel in the center will the panel expand/contract evenly so that the reveal remain the same?

Why in the world would anyone share that info with the customer? I would simply say, sorry it can’t be done, plus my customers already know I am smart :)

We have built many doors like this from many different materials with reveals ranging from 1/8" to 1/2". This is a popular style when a customer wants something a little different. We brand this as "transitional". I've never had a call back or a door failure. It's a frame and panel door like any other, built with space balls like any other, designed for the center panel to expand and contract like any other. If the reveal were to measure 3/32 in the winter and 5/32 in the summer, who cares?

The attached image happens to be the back side of a door in my office, but reverse it and you have exactly what you're describing.

View higher quality, full size image (756 X 1008)

DJS, thanks for the info.
No one would care about 1/16”, i am more concerned if for example (extreme case) if the reveals are 1/4” and the wood moves 3/16” in one direction now you have a 1/16” gap on one side and 1/4” on the other.

I was planning on pinning it in the center but I don’t know if the wood expands evenly right and left.

I have never used space balls, I mostly build furniture now but 25 yrs ago I did a lot of cabinets. So with space balls yow just add the diameter of the ball to the depth of the slot?

Exactly. Space Balls are about 1/4" in diameter so we allow about 3/16" extra beyond the size of the panel. This effectively centers the panel and keeps it centered even if there is expansion and contraction, so long as you do not pin the panel.

I disagree that you can’t predict wood expansion, you most certainly can “predict” shrinkage/expansion of wood. How good your prediction is depends on the amount of information one has but that’s a different discussion.

You are probably correct that I am over thinking this but I am not really loosing sleep over it, just looking for feedback from others who have more experience with this than I do, typically I do panels like these in laid up in veneer so I have never really thought about it.

I also realized last night as you pointed out that because in the bath it may be more stable and won’t see that much expansion/shrinkage anyways.

I am mostly concerned with the reveal staying consistent I am absolutely not concerned about the construction method.

So maybe I listed too much info and the question should have been something like:

- I have a frame and panel, the panel has a 3/16” reveal on all 4 sides of the panel. I want the reveals to stay consistent through seasonal movement if any occurs. If i pin the panel in the center will the panel expand/contract evenly so that the reveal remain the same?

Why in the world would anyone share that info with the customer? I would simply say, sorry it can’t be done, plus my customers already know I am smart :)

Kevin, thanks for the detailed response.

Humidity in shop is not controlled and the vanities will be open in a bath. I think you have provided the answer.

I really want to keep the reveals at a minimum or it looses a clean look that I am going for, I think I will resaw the half inch panels (there are three per panel and makeup a veneered panel.
That way i can stick with 3/32” max gap which is what I was looking for.

I can successfully plane to 3/32” and if brave 1/8” and will glue to 3/8” or 1/2” bb. I am well. Versed in commercial veneer but limited in shop sawn, i have used t2 with success in the past but wonder if I should use a harder glue line in this case

Edit… 1/16” if brave…

Maybe smart wasn't the best choice of words.

I think you got some feed back nobody wants a callback. I'm sure the vanity will be in the house long after your gone.

Thomas, I'm move to Newfoundland 14 years ago right beside St.John's .I work for 20 years in Montreal had my start in Antiques which was a great introduction to cabinetmaking ended up in commercial aircraft private jets for a few years . Then went on my own . I think your ideas are good

The fact that you are worrying about a panel moving more to the left than the right after it is pinned in the middle is madness.

They will expand at more or less the same rate depending on the grain. The differences between those is negligible. If the grain is quatersawn on one side and face sawn on the other then it would possibly show, but who would do that?

Go with the calculator. The vast majority of raised panel doors are based on 1/8" per foot regardless of species. I can't remember ever having a problem in 25 years. 18" panels are wide for solid. I would be concerned about it warping before assembly. Going with a thicker 5/8" or 3/4" panel will warp less than your proposed 1/2".

Everyone else has beaten the size change to death. If you're absolutely concerned about it, put in a mid-stile and 2 panels.

Adam S:
Is it madness? Or is the reveal just a detail that I am interested in getting right and something you don't consider important...

Gary B:
Thanks for the response, that's something I actually didn't think of unfortunately the look doesn't work for the design.

As suspected the reveals I want to maintain are not possible with solid, I am going to re-saw and press to BB which will resolve my concerns.