Framing A Low Pitch Roof

This sizing guide for roof rafters will help determine what you need for your small project.

Framing a low pitch roof.

Or if you want to raise the roof a bit more install fascia around the roof perimeter attached to the new soffit and nail the new roof deck to crown molding above the fascia. This is denoted two ways a 1 3 or 1 4 pitch in fractions and a 6 12 pitch in inches which means the roof rises 6 inches for each 12 inches of run. Erect one truss in. Self adhesive flashing membrane under the shingles prevents leakage on low slope roofs.

Use a framing square to help lay out the notch based on the slope of the roof. Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes. Pitch is the amount of angle or slope the roof has. To provide a framework for the new trusses nail 2 by 6 inch strips of wood around the perimeter of the roof.

Input the pitch of the roof that you calculated above we ll use 7 12 for reference throughout on the framing square. Then apply standard asphalt shingles over the membrane. Sunday august 5 2018 the traditional metal roof types such as 5v crimp shown above and corrugated are rated by the manufacturers for use down to a 3 12 pitch three inches of vertical rise for every foot of horizontal run. Can metal roofing be used on a low slope pitch roof.

There are several variables to consider when determining the proper rafter size. Mark truss locations on the front and back wall caps of the structure. At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing. For our 4 x8 lean to example using a 2 4 rafter the depth of the birdsmouth is limited by the 1 3 depth of the rafter rule.

Use prefabricated mono trusses for the easiest and best framing on a single slope roof. 1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many equivalent products. The membrane will outlast the shingles and seal around all nail penetrations. Get on a ladder with a tape measure.

To transition the eaves the horizontal fascia extends to the last rafter tail and a vertical return finishes the transition. How to frame a single slope roof step 1. This system can also be used for the steep roofs. For lower pitches a built up or continuous roll roofing must be applied to keep the roof waterproof.

On the body of the square the longer side input the 12 and input the 7 on the tongue the shorter side of the square by lining up the stair gauges at the corresponding point on the square. A 2 4 wall with a 2 6 rafter can be notched for a 4 seat. For a low slope residential roof there are two main options.