Common mod bit problems
- Blisters from trapped moisture or poor adhesion
- Open laps and seams
- Cracked or alligatored surfaces where granules have worn off
- Flashing failures at walls, parapets and rooftop units
- Ponding water at low spots and clogged drains
Repair or replace
Localized blisters, seams and flashings are repairable. When the cap sheet is worn across the roof but the system is dry, a coating can restore it. When the insulation is wet or the roof has been patched over and over, we'll show you why replacement is the better spend, and compare mod bit, TPO and PVC so you can choose.
Frequently asked questions
How long does a modified bitumen roof last?
Commonly 15–25 years depending on the system and maintenance.
Is mod bit good for a residential porch roof?
Yes, it's a solid choice for low-slope porches and additions, as is TPO.
Can a modified bitumen roof be coated?
Yes, if the roof is dry. The surface is cleaned and primed, problem areas are repaired, and a coating system is applied. If the insulation is wet, replacement is the better answer.
