Yes—modified bitumen roofing can sometimes be installed over an existing roof, but only if the conditions are right. At L&L Roofing & Construction, we carefully evaluate your current system to decide whether an overlay is possible or if a full tear-off is the safer, longer-lasting choice.
When Overlays Are Possible
- One Existing Layer: Building codes typically allow only one additional roofing layer.
- Good Deck Condition: The roof deck must be solid and free from rot, sagging, or structural damage.
- Dry Insulation: The existing roof must not have trapped moisture or widespread water damage.
- Code Compliance: Local building codes and manufacturer requirements must allow an overlay.
When a Tear-Off Is Required
- If the roof already has two layers.
- If there are leaks, rot, or saturated insulation.
- If warranty requirements call for full removal.
- If the roof structure cannot handle the additional weight.
FAQ: Can Modified Bitumen Be Installed Over an Existing Roof?
Q: Is it cheaper to do an overlay?
A: Yes. Overlays save on tear-off and disposal costs, but they’re only recommended when the roof structure is in good shape.
Q: Will an overlay shorten the roof’s lifespan?
A: Not necessarily, but addressing underlying issues is critical. Covering over damage will only hide problems, not fix them.
Q: Does warranty coverage change with overlays?
A: It depends. Some manufacturers fully warrant overlays if done to spec, while others require full tear-offs.
Q: How do I know if my roof qualifies?
A: A professional inspection is the only way to know for sure. We’ll evaluate your roof honestly and recommend the best solution.
At L&L Roofing & Construction, we believe in doing the right thing—because it’s the right thing. That means we’ll never recommend an overlay unless it truly benefits your property long-term.
Call us today at (770) 874-0372 to schedule a roof inspection and see if modified bitumen can be installed over your existing roof in Gainesville or surrounding areas.