Allowing for movement in T & G Boards

John15 · 10 Jun 2015

My next project is to be two 1.8m high x 900mm wide side gates for my bungalow. I plan to make the frames from Oak and use vertical 100 x 15mm T and G Scandinavian Redwood boards for the infill. The end boards will be housed in a rebate in the stiles and free at the top and bottom. I imagine they will be very moist from the tantalizing treatment but I can leave them for a period to dry out a bit.

My question is what gap should I leave between the boards and how should I fix them to the frame to allow for movement?

John

DTR · 10 Jun 2015

When I built my gates (very similar construction, 100mm T&G) I used a penny as a spacer between the boards. Each board was nailed to the top, middle and bottom rails, and where they crossed the braces, using two nails at each location. Each nail was spaced about an inch from the edge of the board. Not sure if that makes sense?

blackrodd · 10 Jun 2015

I do mine, much as DTR, Above, but I nail the centre board 2 in the top, 2 in the middle to stiffen the brace, and 2 in the bottom.
Then space the boarding out allowing about 2mm each side on 4" or the penny(3mm) on 5", or 6"T&G, including the rebate, and nail these down through the centre only to allow the sides to expand and contract at will.
Try and ensure the oak and the T&G are fairly equal in seasoning, to stop a possible inbalance.in fighting each other.
Don't forget to bevel off all the horizontal rails, to shed any rain water
Regards Rodders

John15 · 10 Jun 2015

Thanks Dave and Rodders for the advise.
The Oak I will be getting is stored undercover so I will have to leave it out for a while to equalize with the T&G.
You both mention nails for fixing the boards. Will these be OK for going into Oak?

John

blackrodd · 10 Jun 2015

I would use Galvanised lost heads, they would be better, 40mm should be long enough, and a thicker gauge.
With ovals, the grain of the boarding you are nailing will tend to either split the board ends, to suit the oak grain, or have a difficulty in not bending the nail as it goes in the oak "sideways" to the grain.
Regards Rodders