Many older flat roofs and low pitched roofs develop damage near the lower eaves. The lower end of a flat roof often forms a small gully from the weight of snow and ice accumulating there as this is the last place for runoff. Cracks in a hot tar roof can lead to leaks in this area. The moisture seeping in will rot roof sheathing, rafter ends and eventually the fascia. Many rowhomes with flatroofs
don’t even have gutters which can often lead to damaged fascia.
After tearing off the roof you’ll need to assess for yourself the amount of damage and repairs that you feel comfortable doing. Take into account the load your roof is bearing especially if it is a hot tar roof.
Steps for repairing rafter ends
Rip off any bad fascia and/or faceboard
The two end rafters will be of utmost importance if there is an overhanging eave that needs replaced.
The two end rafters will help achieve a straight faceboard as they will be the set points for the middle rafters.
Often called scabbing a rafter, you will likely use 2X4 or 2X6 to attach along side your existing rafters. You will need to go far enough back to where the original rafter is solid, good wood plus some.
Using 3-4 inch screws and NOT nails. Nails don’t give as much strength and support to the scabbed rafter.
Attach the first scab to one of the end rafters while zig-zagging your screw pattern for more stability. Screw into the softer wood also as any added support further down the scab is beneficial.
Repeat Step 4 with the other end rafter.
Tack a straight 2 by 4 as a temporary fascia or run a string from the rafter ends of the two you just scabbed. This will be the flush end of your roof ensuring a straight
Scab the inner rafters with the ends of your scabs meeting your flush temporary faceboard or string line from Step 6.
Remove the temporary faceboard and cut the final fascia to proper length and nail onto your new rafter ends.
If you are putting plywood back on your roof, it may be best to screw your plywood to the new rafter scabs.