Framing A Low Pitch Roof

The membrane will outlast the shingles and seal around all nail penetrations.

Framing a low pitch roof.

Can metal roofing be used on a low slope 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. Then apply standard asphalt shingles over the membrane. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.

Metal panel roof systems for low pitch application this system uses a structural metal panel for low pitched metal roofs due to their ability to form a formidable barrier for water. A 2 4 wall with a 2 6 rafter can be notched for a 4 seat. 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. At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing.

Input the pitch of the roof that you calculated above we ll use 7 12 for reference throughout on the framing square. Pitch is the amount of angle or slope the roof has. For a low slope residential roof there are two main options. 1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many equivalent products.

Mark truss locations on the front and back wall caps of the structure. 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. This sizing guide for roof rafters will help determine what you need for your small project.

There are several variables to consider when determining the proper rafter size. 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. 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. 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. Measure the outline of. Get on a ladder with a tape measure. Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes.

Erect one truss in. Use a framing square to help lay out the notch based on the slope of the roof. To provide a framework for the new trusses nail 2 by 6 inch strips of wood around the perimeter of the roof.