Expainsion gaps in external door?

[sprotty]

Hi

I'm building some doors for my garage using oak that we woodmizered up a few years back.
I've got all the timber prepared now, and am looking at the fine detail a bit more....

The picture below is pretty much what I'm trying to create.

My question is, should the vertical T&G boards be spaced slightly to include an expansion gap?
Also how should the T&G boards be glued or just fit loose within the frame (the frame is also tongue and grooved so they should sit within it OK I guess)?

Thanks
Simon

 

[RobinBHM]

Its difficult to advise without knowing what the moisture content of the wood is at present.

If it was kiln dried oak, then I would suggest a gap of 2mm-3mm on a 100mm board

If it is quite wet still, say 15-18% then it may shrink rather than swell.

If you have time you could make some practice t and g and leave it outside under cover and monitor with digital gauge and check to see whether it shrinks or swells.

It is safer generally to make the t and g with decent tongue and leave enough gap. If the t&g swells too much it may well cause the door to buckle-more of an issue than a gap being too big

I personally would make larger top and bottom rails so the hinges are not so near the top and bottom

 

[sprotty]

Thanks,

The woods been stacked and air drying for about 2 years, and I'd guess its moister content at the moment has probably equalized with the environment, but given its going to be getting some rainwater on it when its a door, so I would guess its probably going to swell a bit especially when the weathers a lot damper than it is now.

So leaving a gap seems like a good plan, I guess T&G boards are just left loose in the frame in that case, as gluing would seem to negate the gap? Would you suggest any fixings on the top and bottom of the T&G boards (other than the T&G itself.)?

In terms of the design, the rails etc will be a bit chunkier than pictured, but I've been limited by the timber we cut and the size of my saw bench and planer....Need more toys and a bigger shed...

 

[Beau]

Robin covers it. Impossible to say without knowing the woods moisture content. T&G gets a hard life from soaked for days to baked buy the sun. Defiantly do not glue it in place.

You say " I guess T&G boards are just left loose in the frame in that case, as gluing would seem to negate the gap? Would you suggest any fixings on the top and bottom of the T&G boards (other than the T&G itself.)"
Not quite clear what you have in mind but don't set it into a groove as the water would sit in here and rot out the bottom rail. Best just rebated into the front face and fixed with oval nails then any water that tracks through will get guided out. Got lots of T&G doors here so will take a pick

 

[Beau]

It's not perfect as cracks have formed around the nails on the end but they need fixing back somehow. Less nails would allow more cupping but this will not be so bad on a garage but on a home you can have 99% humidity and rain on the outside while the inner face is subject to 20C and 50% humidity. If you are making your doors nice and thick I would be inclined to run the T&G right through to the bottom of the door to enable water to run clear of the bottom rail which you would make the thickness of the T&G thinner.

 

[sprotty]

OK rebating it and nailing seems simpler, I'd already prepared the top and bottom rails with a tongue on the bottom rail and a groove on the top rail (the thinking being this will prevent water sitting in the groove).
It would be easy enough to just rebate that out as I've not cut the boards yet.

I guess the way I'd envisaged it means the boards have to much movement meaning they could shuffle to one end and open up a gap at the other.

Cheers