How To Cut In Gable Roof To Existing Roof

The gable roof on the porch addition was framed with a dropped structural ridge supporting the common rafters above.

How to cut in gable roof to existing roof.

Then add siding and trim to the new gable roof end. Before you start cutting you first need to determine how long your roof rafters need to be and the angles at which you ll cut the top and bottom of the rafter. Use a tape measure to measure the entire width of your building. These days cut ups or roofs with a lot of valleys dormers and other features are increasingly popular.

Line up your framing square again to make a triangle with the mark. Measure as precisely as possible down to the 1 4 inch 0 64 cm 1 8 inch 0 32 cm or 1 16 inch 0 16 cm. Continue to measure 2 x 4 s to allow nailing at each truss until you reach the end of your roof and add the additional 6 inches and 1 1 2 inches for that end. Once new trusses are secured sheath the roof with oriented strand board osb lay down roofing paper then nail on shingles.

We cut the rafters to length on the porch. Up from the valley center and cut through the shingles and underlayment. The 6 inches of rigid insulation added to the top of the existing roof deck needed to be done in a manner that was invisible. Now comes the really really big point.

At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing. Creating a small triangular extension of the existing roof. In the case of a lean to roof over an addition the existing rafters will have to be cut away to accommodate the addition and the shed roof will require support where. Roofs are basically five types.

The easiest way to tie in the new shingles with the old is with a cut valley see four ways to shingle a valley. Cut the small triangle out with a hand saw or circular saw. Attaching below the ridge. Shed gable hip gambrel and mansard.

Another common design in the northeast is the saltbox which is a gable roof with one longer side. Finally cut slots in the underside of each rafter flush against the wall with a saws all. Then install new ridge board tying it to the old roof by cutting back part of the original ridge board so there is overlap. Install metal drip edge at the eaves.

Measure about 7 8 inch 22 mm from the end of your rafter using your framing square. Next cut out slots in rafters so a 2 x 4 will sit flush with it on the cap plate. The roofing cement will resist possible leaks overnight.