Screw the batten in place nailing may dislodge tiles.
How to repair a hole in roof felt.
Alternately get more roofing felt and a tube of roofing caulk and glue felt patches over the rips with the caulk.
We had a problem with our shed workshop flat felt roof leaking and needed a quick repair.
Use a caulking gun to apply caulk to seal any holes that appear in the roof.
From inside cut across the lowest part of the damage from rafter to rafter cut a piece of slaters felt 50 100mm wider than the rafter rafter size and taper this both sides slide the tapered edge into the cut and pin the sides to the rafters using lengths of batten.
To make even minor roof repairs you must have an ordinary ladder and a roof ladder.
A roof ladder has rubber wheels and hooks at one end.
Use the putty knife or your finger to spread the caulk around to cover the hole.
The wheels allow it to be pushed up the roof without dislodging loose tiles.
Start low soaking the area just above where the leak appears in the house.
A common problem is when roofing felt on a roof with an enclosed soffit disintegrates around the eaves of a roof.
Repairing felt around the eaves.
If a leak is difficult to find enlist a helper and go up on the roof with a garden hose.
Isolate areas when you run the hose.
The ladder to the roof should have a stand off bracket so it rests against the wall rather than the guttering.
Wind driven water that would normally flow down the felt and into the gutter instead drips onto the soffit and then back onto the ceiling of the room below through gaps in the felt.