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.
How to stop leaks in roof valley.
Trowel the roofing tar into the leak on the underside of the roof deck using a putty knife.
Push the shingle or plywood into the tar and trowel more roofing tar around the edges of the patch.
The best way to find and stop the roof leak is to start over and roof the valley the right way.
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.
During long dry spells leaves and perhaps other debris gather in the valleys.
The roof tiles along the sides of the valley also help in trapping the debris.
A properly flashed roof valley should have an ice and water shield installed with roofing felt being properly secured over the ice and water.
Begin by removing the shingles down to the wood sheathing and slip a strip of adhesive ice and water barrier available where roofing repair products are sold under the soffit main roof joint.
We removed all old roofing material down to the original wood deck.
Remove debris remove all debris from roof valleys so nothing is touching your roof.
Then installed a layer of gaf storm guard underlayment and 20 valley flashing.
And that s what we ve done here montgomery s old cloverdale neighborhood.
Move to the highest end of the valley and work your way down cleaning shingles from both sides of the valley whether they re damaged or not.
Eventually water pools behind the dam and works its way back up under the shingles and under the soffit until it finds an opening through the roof.
Missing ice water shield.
Leaves and valleys don t work well together.
In order to lay the flashing the shingles on the roof will have to be removed.
Re shingle roof valleys install ice and water shield under shingles or install metal roof flashing and re shingle the valley.
If you have sarking then it is quite possible that the leak is contained and you don t know that your roof is leaking.
The solution begins with good flashing since this should stop leaks from rainfall and might stop the leaks from ice dams as well.