Short answer
Mineral roll roofing is the budget, single layer roof for sloped outbuildings: nailed and cemented, at least 1 in 12 by code and often 2 in 12 by the wrapper. Modified bitumen (SBS or APP) is a thicker, reinforced, polymer modified membrane laid as a base and cap system for low slope roofs, installed by torch, hot asphalt, cold adhesive or, for DIY, self-adhered sheets. It costs more and is estimated to last much longer.
Side by side
Roll roofing vs modified bitumen
| Mineral roll roofing | Modified bitumen | |
|---|---|---|
| Made of | Asphalt on a felt or glass mat, granule face | Polymer modified asphalt (SBS or APP) with polyester or glass reinforcement |
| Layers | One (two with 19 in selvage) | Base plus cap, sometimes more |
| Slope | At least 1 in 12 by code; often 2 in 12 by wrapper | Low slope systems |
| Install | Nails and lap cement | Self-adhered, cold adhesive, hot asphalt or torch |
| Installed cost (estimates) | $2.00 to $5.50 per sq ft | $4.25 to $6 per sq ft |
| Life (estimates) | About 5 to 15 years | Up to about 30 years |
Costs: roll roofing from HomeGuide, modified bitumen and life spans from Hunker. Code slope from the IRC R905.5 handout. CertainTeed describes its Flintlastic SA Cap as a polyester reinforced SBS sheet (CertainTeed).
When each makes sense
- Mineral roll roofing: sheds, coops, barns and detached garages with real slope, where cost matters most. See the mineral roll guide.
- Self-adhered modified bitumen: porches, additions and garages with low slopes, or anywhere you want fewer nail holes and a longer life. See peel-and-stick roll roofing.
- Torch or hot applied modified bitumen: larger low slope roofs, by a roofer.
Questions people ask
Is modified bitumen the same as roll roofing?
It comes in rolls, so people call it roll roofing, but it is a different material. Modified bitumen adds polymers such as SBS to the asphalt and has a reinforcing mat, which makes it thicker, more flexible and suited to low slopes.
Which lasts longer?
Modified bitumen, by most estimates. Hunker gives asphalt roll roofing five to 15 years and modified bitumen as long as 30 years. Both depend on slope, climate and workmanship.
Can I install modified bitumen myself?
Torch applied modified bitumen is a job for trained roofers: it involves an open flame on a roof. Self-adhered SBS systems are made to go down without torches or hot asphalt and are a reasonable DIY job on a small porch or garage roof.
What is the difference between SBS and APP?
They are two polymer types. SBS makes the asphalt rubbery and is used in self-adhered and cold applied sheets. APP makes it more plastic and is usually torch applied. For DIY, look for SBS self-adhered products.
Sources
Last reviewed October 12, 2026. Products and listings change; check the data sheet and wrapper before you buy, follow the maker’s instructions, and check your local building code.