Repair work is most of it. Replacement when a roof genuinely needs it, not before.
Leak repair
Tracing the entry point rather than patching the stain, then fixing it properly.
Roof repair
Shingles, flashing and underlay. Small problems dealt with before they become a new roof.
Skylights
Repair, resealing, replacement and new installation.
Gutters
Repair and clearing, including the joints and downpipes that cause most of the trouble.
Roof cleaning
Moss and debris removal, which buys years on a roof that is otherwise sound.
Flat and commercial roofs
Torch on and membrane work on flat roofs and commercial buildings.