Patio Roof Joist Spacing

So the space between rafters can be greater without reducing the maximum span.

Patio roof joist spacing.

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. The larger the deck the larger the joists. 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.

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. The smallest beams for patio covers are typically 4 by 6. A 4 by 10 can usually span up to 12 feet between posts. There are several variables to consider when determining the proper rafter size.

2x10 to 15 feet and 2x12 to 18 feet. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. A 2x8 up to 12 feet.

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. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. 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. The same concept holds true for roof trusses.

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. 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. In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts.