How To Replace Roof Valley Flashing

Slip a piece of sheet metal flashing under the top layer of shingles to protect the bottom layer in the valley while you cut the shingles with a hook blade.

How to replace roof valley flashing.

Step 9 cut corners and apply cement. Second step flashing needs to extend 8 to 14 inches above the shingles according to the national roofing contractors association nrca. From drip edge to valley flashing december 25 2018 drip edge metal valley flashing dormer chimney and kick out flashing shed water away from the connections between roofs walls chimneys and other building assemblies. Cut the top layer of shingles along the chalkline.

Install an underlayment centered in the roof valley. Cut each side at the upper end of the valley to conform with the. If this is a repair job the siding must also be removed and replaced with the flashing. With a clean valley you can lay down some peel and stick roofing membrane.

First step flashing must be installed before the siding so that the siding can cover the top of the flashing. Learn the three methods of shingling a roof valley the advantages and disadvantages of each how to choose valley flashing and how to shingle an open valley. Architectural shingle installation is especially critical in roof valleys where iko recommends an open valley installation. Fold the top over the roof ridge and cut the bottom along the drip edge metal.

The top joinery of both valleys when they meet on the same plane of roof is shown here. Position a new vent pipe flashing over the vent push it down into place and nail where shingles will cover it. If the ice and water shield is missing then you will have to remove the shingles on both sides along the valley put ice and water shield in place and re shingle the roof. Cut each side of the flashing at the lower end to conform with the corresponding edges of the roof using sheet metal cutters.

Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic. I have my valley custom made with water trough to help with leaking b. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing. To replace flashing around the vent pipe first remove the shingles covering the flange at the back and sides.

A properly flashed roof valley should have an ice and water shield installed with roofing felt being properly secured over the ice and water.