Sizing Roof Supports

There are a lot of variables to consider when sizing a supporting beam for a porch roof or any area in your home where a load must be carried.

Sizing roof supports.

For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. If there is also a beam in the middle of the roof divide the total load by three. There are a few things to know before erecting a protective roof. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

Roof framing suggestions canadian guidelines. Beams can be solid lumber or be built from lengths of 2 by lumber nailed together with 1 2 inch pressure treated plywood spacers in between this forms a 3 1 2 inch thick beam that is equal to the width of a 4 by post. Ridge boards can only be used in roofs with slopes from 3 in 12 up to 12 in 12. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.

The lengths and sizes of joists vary depending on the species and quality of the lumber used. While i know your idea seems logical and it might work consulting with an architect or engineer is the only way to know for sure. Raised floor homes look great and protect homeowners against risks from flooding and subsiding soils. Maximum rafter spans for a patio roof.

This article excerpts from provides copies of roof framing suggestions from canadian building codes and the cmhc wood frame house construction guide. The sizes of your porch roof framing members their spacing the type of. For heavy roofs or in. Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam.

If one side of the roof is supported by the house and the other side is supported by the beam divide the total load by two as the beam is only supporting half of the roof. The 1 grade. Both diyers and building professionals will like these garden and outdoor living ideas and plans. This sizing guide for roof rafters will help determine what you need for your small project.

A roof on a treasured deck can open up more possibilities for enjoying the space throughout the year. There are several variables to consider when determining the proper rafter size. If our example roof has only one beam it must carry half of the total load or 4 000 pounds. Wood beam calculator american wood council website rafter and joist span faq.

Building a roof over a deck allows you to grill relax play or simply stay quiet and listen to nature whether rain or shine.