Roof Beam Size

Determining the ridge beam height.

Roof beam size.

If there is are any questions about anything else then you should contact your supplier or an engineer. Calculate the initial value for d then round it up to the nearest inch. It has been my experience to never use a beam smaller than a two ply 2 x 8. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry.

Maximum rafter spans for a patio roof. Most interior beams need to include the roof load. 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. Window door garage door headers supporting roof loads only.

In the example d calculates to 7 75. Window door garage door headers supporting roof wall floor loads. This means the example porch would need a 6 inch by 8 inch beam. The finished ridge beam height z above the top of the wall will be m plus the y height.

This tells you the size of the beam needed to support the porch s roof. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications. For heavy roofs or in.