Post And Beam Roof Framing

Pacific post beam was founded in 1983 in sandpoint idaho as a custom builder of timber frame homes we relocated to san luis obispo in 1986.

Post and beam roof framing.

Post and beam typically uses half lap joinery with hidden fasteners and sometimes decorative metal braces. A timber frame truss roof with ridge beam purlins and common rafters is a stunning combination that creates visual interest and structural complexity. If your span table shows the roof beam cannot support the roof rafters for the whole length of your house you will want to choose a built up roof beam whose maximum spans are the same as or slightly longer than your chosen floor beam spans. In the same way you may need posts to support your roof beam.

Roof framing system choose any combination of wall floor and roof systems to suit your style and fit your budget. Post and beam construction has a very similar aesthetic and the joints can look similar but the stark difference is the connections are simple sometimes made with plates and bolts. Some post and beam projects are done without the plates. The beams of both techniques are fully exposed to the inside of the structure.

In the 37 years we have been crafting timberframes we have designed and built hundreds of timberframes and timber trusses for homes restaurants and wineries. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. If you know the slope x in 12 you want to use for your roof framing design you can use it along with the run r to determine the height of the ridge beam for example if the slope is 4 in 12 and the run is 12 feet the ridge beam height m will be 4 feet. For those projects the connection is made by lag bolting the timber components together.

Timber frame homes are typically much more expensive than post and beam. However a modified post and beam can be built almost entirely out of cheap lightweight 2 x boards and the joinery is simply cleats and fasteners. Above these components is a rack of common rafters. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

There is a hierarchy of timber framing at work here with trusses supporting the ridge and purlin beams. Whereas timber frame uses mortise and tenon joinery secured with wooden pegs. Traditional timber framing requires very complex joinery and both timber framing and post and beam use heavy members that one can t hoist alone.