Splice Roof Rafters

How to splice a roof rafter plate.

Splice roof rafters.

Some roofs are much longer than average milled board lengths which creates the need to splice one ridge board to the end of another ridge board. Rafter splice forgive the crude drawing will post pic but it is hard to see. A splice should end between rafters not where a rafter lands directly on the splice. When you prepare to make the splice note the rafters location.

The roof rafters are 2x8 on 16 centers with 2x10 ridges. Rafter splicing is typically used as a last resort for erecting rafters and is not generally the preferred method of constructing roofs. Several have a plywood scab brace on the side but several do not. A ridge board is a much better way to secure rafters to your roof and will almost always be a better way to go.

In this case the framer just needed a longer rafter. Rafter plates are almost always spliced due to the length of most structures. In this case the rafter as a whole is actually stronger than it would have been because the splice is more than adequate and the plywood adds to the strength. Calculate where a ridge beam splice will be needed.

A 30 foot roof for instance will need at least two boards. A 16 foot board will end at a rafter with 24 inch spacing. Pictured at left is a 2x6 rafter spliced together using 3 4 plywood.