1 ft 0 3048 m.
Safe spans for no 1 roof rafters.
Live load is weight of furniture wind snow and more.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
The 1 grade material is more expensive than the 2 grade but if you can use fewer or smaller 1 grade joists or rafters in your design you may actually save money.
Dead load weight of structure and fixed loads 15 lbs ft 2.
Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.
Calculations determine the maximum spacing based on the material used rafter size and load the roof needs to hold so that the roof is safe and meets all building codes.
The tables permit a bearing length of up to 3 5 inches but since 1 5 is probably the worst case that you ll encounter for joist or rafter bearing it s a safe value.
This post may contain affiliate links.
1 psf lb f ft 2 47 88 n m 2.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
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.
Span calculator for wood joists and rafters available for the iphone.
View joist rafter tables.
Patio roof maximum beam rafter spans.
Although there is not one standard rafter spacing measurement many builders follow standard increments for simplicity.
2 are indicated below.
Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.
While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator.
This table is simply a sample and may not be valid for your region.
Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.
For more information see our disclosures here.
Span calculator for wood joists and rafters also available for the android os.
