Roofing / Restoration / Built-up
Built-up roof restoration
Convert a smooth or gravel built-up roof to a sealed, insulated spray foam system, eliminating the seams and flood coats that fail with age.
- Failure point
- Flood coat, ply separation
- Method
- SPF
- Adds
- ~R-6.5 / in
- ROI
- Moderate
- Warranty
- 10 / 15 / 20 yr
What goes wrong, and where
Built-up roofing (BUR) is the layered asphalt-and-felt system, smooth or gravel-surfaced, found on older commercial buildings. As it ages the flood coat cracks, the plies separate, and water tracks between layers. Because the surface is irregular and the failures are between plies, the right restoration is usually spray foam: SPF fills the contours, bonds the assembly into one continuous membrane, and adds insulation the original roof never had.
Flood coat that has cracked
The asphalt flood coat that waterproofs a BUR roof grows brittle and crazes with age, opening paths for water into the plies below.
Plies that have separated
Built-up roofs fail between layers, where felts delaminate and trap water. SPF bonds the assembly into a single continuous surface.
Why spray foam here
SPF fills the irregular BUR surface, self-flashes the details, and adds about R-6.5 per inch of insulation the original roof never had.
Gravel handled first
On a gravel-surfaced BUR, loose ballast is removed and the surface is prepared so the foam bonds to a sound substrate.
The method that fits
Spray foam (SPF)
SPF fills the irregular built-up surface, bonds the plies into one continuous membrane, and adds about R-6.5 per inch of insulation the original roof lacked.
Moderate
Restoration keeps the deck and insulation in place, so the spend goes to the membrane that fails, not to a tear-off and a full rebuild.
Restoration on this roof
- 01
Survey
We map trapped moisture between plies and confirm the deck is sound enough to recover.
- 02
Prepare
Loose gravel is removed, wet areas are cut out, and the surface is prepared for adhesion.
- 03
Spray foam
Closed-cell SPF is sprayed over the prepared BUR, self-flashing every detail in a continuous pass.
- 04
Topcoat
A silicone topcoat protects the foam and sets the 10, 15, or 20-year warranty term.
Single-ply vs. metal vs. built-up
The three commercial substrates fail differently, and the right renewal path differs too: coating for single-ply and metal, spray foam conversion for built-up. All three renew in place without a tear-off. Here is how they compare.
| Attribute | Single-ply (TPO / EPDM / PVC) | Metal panel | Built-up (BUR) |
|---|---|---|---|
| First failure point | Seams and laps | Seams, fasteners, rust | Flood coat, ply separation |
| How water gets in | Open seams, shrinkage stress at flashings | Lap joints and aging fastener gaskets | Cracked flood coat, water tracking between plies |
| Renewal method | Fluid-applied coating | Coating (SPF alternative) | Spray foam conversion |
| Adds insulation | No | Only with the SPF option | Yes, ~R-6.5 / in |
| Tear-off required | No | No | Rarely |
| Restored warranty | 10 / 15 / 20 yr | 10 / 15 / 20 yr | 10 / 15 / 20 yr |
| Ruled out when | Wet insulation or failed adhesion | Structural rust-through in panels | Widespread trapped moisture |
Typical industry figures for comparison. Actual condition and restorability are confirmed by moisture survey during the assessment.
Different roof, same approach
- TPO, EPDM, PVCSingle-ply restoration
- Ribbed & standing seamMetal roof coating
- All substratesRestoration overview
All restoration work is self-performed by A-1 with 10, 15, and 20-year warranties.
Built-up restoration questions
Why spray foam instead of a coating on built-up?
Built-up roofs have an irregular surface and fail between plies. Spray foam fills the contours and bonds the assembly into one continuous membrane, which a thin coating over a moving, layered roof cannot do as well. SPF also adds insulation.
Can you restore both smooth and gravel BUR?
Yes. Smooth BUR is cleaned and prepared directly. On gravel-surfaced BUR, loose ballast is removed and the surface is prepared so the foam bonds to a sound substrate.
Do you have to tear off the built-up roof?
Rarely. When the deck is sound and trapped moisture is limited, SPF is sprayed over the prepared BUR, which avoids a full tear-off. Wet areas are removed first.
Does the foam add insulation?
Yes. Closed-cell SPF adds about R-6.5 per inch of continuous, seamless insulation, which most older built-up roofs lack.
How is the roof finished?
A silicone topcoat is sprayed over the cured foam to protect it from UV and set the warranty term, the same as on an SPF roof.
How long does a restored built-up roof last?
The converted SPF system carries a 10, 15, or 20-year warranty by topcoat thickness and is renewable on a recoat cycle.
Convert your built-up roof to a sealed SPF system
If the deck is sound, SPF recovers the roof in place and adds the insulation it never had. We confirm with a moisture survey first.
41-year commercial roofing and insulation record