Screw slots for ledge and brace door?

[krismusic]

Hello. I've got to make an external door for a brick built outhouse at my friends 400 year old cottage. I intend to use 5" decking to make a ledge and brace door. Do I need to use slotted holes where I screw the planks onto the rails to allow for expansion? If so does anyone know a good way of machining the slots? Any help gratefully received as are any comments about the general plan. 8)

 

[Jacob]

Nails. Longer than the overall thickness so they can be punched in and clenched over on the other side.

 

[Steve Maskery]

Jacob is right, the trad way to do this is with cut nails.

However, if you MUST use screws, you can cut a hidden slot on the rear face of the cad with a biscuit jointer. The screw head is free to move with the board but the shank of the screw can move in the slot (although if each board is only 5" and not glued together I shouldn't think that exceessive wood movement is an issue).

But do what they'd done for years and use nails.
S