Framing A Low Pitch Roof

Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.

Framing a low pitch roof.

At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing. 1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many equivalent products. Then apply standard asphalt shingles over the membrane. Get on a ladder with a tape measure.

Use a framing square to help lay out the notch based on the slope of the roof. This sizing guide for roof rafters will help determine what you need for your small project. This system can also be used for the steep roofs. To transition the eaves the horizontal fascia extends to the last rafter tail and a vertical return finishes the transition.

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. To provide a framework for the new trusses nail 2 by 6 inch strips of wood around the perimeter of the roof. 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. 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.

How to frame a single slope roof step 1. The membrane will outlast the shingles and seal around all nail penetrations. Input the pitch of the roof that you calculated above we ll use 7 12 for reference throughout on the framing square. Measure the outline of.

For a low slope residential roof there are two main options. A 2 4 wall with a 2 6 rafter can be notched for a 4 seat. Use prefabricated mono trusses for the easiest and best framing on a single slope roof. Erect one truss in.

Mark truss locations on the front and back wall caps of the structure. 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. For lower pitches a built up or continuous roll roofing must be applied to keep the roof waterproof.

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. 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.