presdo
November 14, 2013, 2:32am
3
iab:
What joinery are you using for the 2 boards that are perpendicular to the other 10 boards? Sliding tenon?
For those unaware, wood expands and contracts perpendicular to the grain. As a rule of thumb, 1/16" of movement for every 12". If this is 48" wide, that means 1/4" of movement.
No screw in the world can stop that movement from happening. If a sliding tenon was not used on those two perpendicular boards, something has got to give. If it was made in the summer when the wood swells, the 10 boards will contract in the winter, the 2 on the end will became detached from the other 8 when they start hitting up against the 2 perpendicular boards. If it was made in the winter, when it swells in the summer, you will get a 1/8" gap between the 2 end boards and the 2 perpendicular boards.
A sliding tenon was used, and it was pegged together. The rest of the pieces are put together not only with glue, but also dowels. Wood swell was taken into account. The wood was also sealed to prevent the wood from swelling too much.