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.
Repair roof valley flashing.
At the top edge of your roof valley check to make sure the flashing is properly angled to line up with the slope of the roof.
Recommended procedures of basic valley flashing installation.
The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak.
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.
Use roofing nails to secure the flashing in place driving nails at 1 foot intervals along the outer edges of each side from top to bottom.
The valley flashing laid over the joint where the two roofs meet should overlap the step flashing at least 2 in.
Repairing a roof valley involves removing some shingles and installing a.
Toronto s roof repair specialists http www mrroofrepair ca show the cause of a major interior roof leak.
A crack in the valley can cause major damage and i.
While some skylight manufacturers include flashing in their products sometimes roofing professionals have to create it or purchase it separately.
Use a metal cutter to alter the length of the flashing to ensure it lines up with your roof s lower edges.
Then reshingle sliding metal step flashing behind the fascia board the trim behind the gutter.
This should cover the most leak prone areas.
A properly flashed roof valley should have an ice and water shield installed with roofing felt being properly secured over the ice and water.
Lap successive sheets of metal flashing a minimum of 12 inches and seal laps.
Once the roof valley has begun to leak you will need to cover the valley with flashing in order to prevent a repeat of the problem.
In order to lay the flashing the shingles on the roof will have to be removed.
If leaks continue to occur from ice dams consider installing roof edge heating cables.
Install an underlayment centered in the roof valley.
Then install a non corrosive metal valley flashing of 24 minimum width.
Replace all shingles you removed making sure their edges are at least 1 inch from the elevated center of the flashing.