Framing A Low Pitch Roof

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.

Framing a low pitch roof.

To transition the eaves the horizontal fascia extends to the last rafter tail and a vertical return finishes the transition. Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes. 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. 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.

This sizing guide for roof rafters will help determine what you need for your small project. A 2 4 wall with a 2 6 rafter can be notched for a 4 seat. This system can also be used for the steep roofs. For a low slope residential roof there are two main options.

Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. 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. Use prefabricated mono trusses for the easiest and best framing on a single slope roof. At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing.

Mark truss locations on the front and back wall caps of the structure. Use a framing square to help lay out the notch based on the slope of the roof. Get on a ladder with a tape measure. For lower pitches a built up or continuous roll roofing must be applied to keep the roof waterproof.

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. Pitch is the amount of angle or slope the roof has. The membrane will outlast the shingles and seal around all nail penetrations. 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. Can metal roofing be used on a low slope pitch roof. Erect one truss in. How to frame a single slope roof step 1.

There are several variables to consider when determining the proper rafter size. Self adhesive flashing membrane under the shingles prevents leakage on low slope roofs. 1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many equivalent products.