How To Support 20 Foot Roof

Better design with truss 2 feet deep or more depending on snow load.

How to support 20 foot roof.

Multiply the loading per square foot by the area in square feet of the surface which the beams will be supporting. Multiply the load per square foot by the total area of the roof. Large 8 x 8 posts are necessary for the use of supporting a porch roof. Calculate the weight the beam must support.

There are several variables to consider when determining the proper rafter size. For a flat roof with snow loading this is 25 lbs. Feet more in presence of snow. If you think you d prefer an overhang style truss adjust the measurements for your top chords accordingly.

I want to know if i take 2x4 s and routed 2 1 2 in channels the length of the 2x4 and used 1 2 inch x 5 inch plywood sandwiched between will support the 26 foot span of roof read more. For larger porches such as wrap around porches you will want to make sure that the support is more than you need. Per square foot for northern areas of the u s. I have a span of 26 feet.

Almost any wood will do the same geometry of beam or truss is the important thing. For rooms which are heavily frequented it may be 50 lbs. This sizing guide for roof rafters will help determine what you need for your small project. If smaller beam will sag ugly.

Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge. Multiplied by 40 pounds per square foot equals 8 000 pounds. The larger the roof is the more support that you are going to need. The steeper the roof the more expensive the trusses get because the longer the boards get and the more roof area increases.

Just keep in mind that if the length of the board size is more than 20 feet then you need to use a more expensive type of lvl board and not a traditional pine board for this longer length. If an example roof is 10 feet by 20 feet the total area is 200 square feet. For a 20 foot span wood beam needs to be minimum 18 inches deep. This number represents the total load that your roof must carry.

Minimum roof loading is 20 lb sq. The vertical rise of the top chord per 12 horizontal inches is the roof pitch or slope. For example 4 12 pitch means 4 inches of rise in 12 inches of run.