The nail will provide a path for the water.
How to repair leaking roof in winter.
Step 2 place a bucket underneath the nail to catch the water as it runs down the nail.
This will freeze the leaking water in place but you ll still need to deal with the ice dam or it will melt and start leaking again.
The roof shingles should be softened and flattened as the shingles tend to curl up in winter.
Make use of the flame carefully on the curled shingle edges.
The shingles can be warmed up with a propane torch.
In the winter a dab of roofing cement or tar should be added to each shingle to bond them together until the tar strip is activated in warmer weather.
To stop the leak use a long handled roof rake to remove snow from your roof or blow cold air onto the area of the roof that is leaking in your attic using a box fan.
Isolate areas when you run the hose.
Insert a nail in the hole where water is leaking through the roof.
The tar strip needs to be about 60f to activate.
Locate the leaking source and search for the damaged or missing shingles and make a list of the areas to be repaired.
While temperature is below freezing at 7 degrees and ot.
For example soak the downhill side of a chimney first then each side then the top on both sides.
Patch the nail or screw holes by slipping a piece of roof flashing underneath the shingle.
If a leak is difficult to find enlist a helper and go up on the roof with a garden hose.