The process involves one simple equation and some knowledge of the loads that the beam will carry.
Roof beam design.
Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
The design of concrete beam includes the estimation of cross section dimension and reinforcement area to resist applied loads.
This calculator matches up with 90 of the applications in the 2012 international residential code book.
Here we have a wood framed gable roof.
Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3.
For a porch roof the beam needs to be sized according to the maximum snow loads in your area and you must know enough about the porch design to determine how the load will be distributed and over what distance the beam will carry the load.
Continuing on from part 3.
Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
Design of rectangular reinforced concrete beam procedure.
The structural design for gravity loads involves evaluating each member for performance under the anticipated live loads dead loads and a combined force of live load plus dead load often called the total load or tl.
A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
If there is are any questions about anything else then you should contact your supplier or an engineer.
Most interior beams need to include the roof load.
Poorly constructed roofs endanger the people living in a building so you need to make the roof compatible to the rest of the building in a well engineered style.
The colour and material of the roof complement the structural integrity of a building.
There are two approaches for the design of beams.
Firstly begin the design by selecting depth and width of the beam then compute reinforcement area.
The loads on the ridge beam are carried by vertical posts at the beam ends down through the building structural walls to the building foundation.
The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.
The design process starts at the roof and continues down to the foundation.
Open source wood find tools designing with roof rafter span tables long span 35 lvl beam design roofdek manual structural roof deckingtimber steel framing manual single span ridge beamglulam ridge beam span.
It has been my experience to never use a beam smaller than a two ply 2 x 8.
