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.
Roof repair valley flashing.
Flashing a humpy old roof valley requires a little give and take and a backup plan.
In order to lay the flashing the shingles on the roof will have to be removed.
Toronto s roof repair specialists http www mrroofrepair ca show the cause of a major interior roof leak.
Metal flashing is used to divert water.
How to repair roof flashing small holes or corroded spots in flashing can be easily repaired.
Roof flashing is a thin material usually galvanized steel that professional roofers use to direct water away from critical areas of the roof wherever the roof plane meets a vertical surface like a wall or a dormer.
Removing the shingles in the valley area and preparing to install a rubber membrane a metal flashing was installed to give the rubber support for when people walk on the roof this will be the place where they step.
A metal lining under the membrane secures that the valley will never puncture again.
You may want to carefully measure the flashing and only lift up as many shingles as you need to get that into the roof or you may want to lift up a number near to the valley in order to ensure that the roof is fully protected in the future.
Then install a non corrosive metal valley flashing of 24 minimum width lap successive sheets of metal flashing a minimum of 12 inches and seal laps.
In other cases shingles are overlapped to make a valley and water from harsh rains can find a way under the shingles.
First roughen the area around the hole with a wire brush or sandpaper and then clean it.
A crack in the valley can cause major damage and i.
Lile points out that valleys lined with roll roofing are not as durable.
Nrca lile recommends that roof valley flashing metal for open roof valleys should be 26 gauge 0 45mm galvanized steel or equivalent noncorrosive nonstaining metal.
A properly flashed roof valley should have an ice and water shield installed with roofing felt being properly secured over the ice and water.
Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic.
Flashing is installed to surround roof features such as vents chimneys and skylights.
Install an underlayment centered in the roof valley.