Patio Roof Joist Spacing

If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts.

Patio roof joist spacing.

Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. A 4 by 10 can usually span up to 12 feet between posts. If attaching a patio roof to a ledger beneath the eaves does not allow for enough headroom you can set the new patio roof s rafters on the wall s top plate.

In general terms joists spaced 16 inches on center can span 1 5 times in feet their depth in inches. On a two story house you can usually tie the ledger into a band joist also called a rim joist located between the floors as shown below. Install a roof joist at each corner of the roof and then from these you measure the distance for the next roof joist and so on until they all are in place. So the space between rafters can be greater without reducing the maximum span.

Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size. In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts. 2x10 to 15 feet and 2x12 to 18 feet. There are several variables to consider when determining the proper rafter size.

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. The smallest beams for patio covers are typically 4 by 6. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope.

A 2x8 up to 12 feet. The same concept holds true for roof trusses. If the size of the roof is not even you will end up installing 2 or more joists closer together than 16 inches.