Built-Up Roofing in Tuscaloosa, AL
Gravel scattered over layered felts is what a superintendent finds on a built-up roof, and the first move is to sweep a few square feet clear and look at the surface underneath, because a BUR hides alligatored bitumen, blisters and exposed felts under its stone. Our crews repair, recover and replace built-up roofs on commercial buildings in Tuscaloosa, AL, and we finish each walk with the same list: roof sections ranked by condition, with the number of plies, the drainage and the edge metal of each one written so the asset manager can carry it on the books. Where a roof is old enough that nobody has the drawings, the walk and a few cores become the drawings.
Felts, Bitumen and Surfacing
A built-up roof is a laminate of reinforcing felts or fabrics set in hot asphalt or cold adhesive, topped with a surfacing: gravel embedded in a flood coat, a mineral cap sheet or a coating. Three or four plies are common, and each layer adds redundancy. Flashings at walls and curbs are built from the same felts and finished with a surface treatment. Hot asphalt has to be applied at the right temperature, and plies that are laid in a cold or damp moment trap air that becomes blisters later. The quality of the original work is visible in the lap overlap, the flood coat thickness and the neatness of the flashing felts, and we read those details as a record of how the roof was put down.
The system's age is its history. A roof that has been recovered, patched and re-flooded may have more layers than the drawings show, and the weight of those layers matters to the deck below.
Alligatoring, Blisters and Open Felts
On an aging BUR, the common findings are alligatored bitumen where the surface has crazed, blisters between plies, ridges at deck joints, exposed felts where gravel has migrated and flashing that has pulled away from a wall. We sweep gravel at sample points, probe suspect blisters and walk the drains. We also look at the history of repairs: smeared roof cement over a split, patches with no felt behind them, and gravel pushed into a repair without a coat of asphalt. Layers of cement build up over years and hide the original problem, so the roof plan marks each patch with a date if one is known and a note on how long it has held.
A core cut is the quickest way to count plies, see the condition of the felts and find wet insulation. Where wet insulation is confirmed, we map its extent with a moisture survey and decide whether a section is repaired or removed. Many BUR leaks track a long way along the plies before they show inside.
Older Downtown and Institutional Roofs
Built-up roofs turn up on older commercial and institutional buildings, where they have a long record. Downtown Tuscaloosa, the seat of Tuscaloosa County on the Black Warrior River, keeps government and institutional buildings central to its market, and a campus of 297 buildings at the University of Alabama or 25 major buildings at the Tuscaloosa VA Medical Center will hold roofs of many ages and types. Hospitals, schools and city buildings add scheduling constraints that the roof type does not. Noise, odor from hot work and the position of fresh-air intakes decide which method can be used, and on occupied buildings a cold-applied built-up system or a different assembly may be the practical choice.
We do not assume the type: we identify it on the roof. Where a built-up system is found, we record plies, surfacing and condition, and match any repair to what is there.
Gravel, Edges and Storm Winds
Gravel can become a hazard in high wind, and a ballasted surface needs perimeter attention. An EF4 tornado raked 35th Street and 15th Street on April 27, 2011 with winds estimated near 190 mph, and straight-line gusts of 90 to 100 mph were surveyed north of Northport in May 2025. Loose gravel, torn flashing and displaced edge metal are the storm findings we record first.
We check the edge metal, the fastening and the cant strip at the wall, and we note whether loose stone at the perimeter has left the felts exposed. Where gravel has blown off, we replace it at the recommended rate and depth, and where the felts show through we add a flood coat so the exposed plies are protected from sun and traffic.
Ponding, Drains and Heat
Standing water speeds the breakdown of bitumen, and the city's roughly 53.5 inches of rain a year gives it plenty of chances. At the 107 F record high, asphalt softens and flashings shift, so wall bases and curbs show it first. We note ponded areas after a storm, check strainers and sumps and recommend tapered insulation if a replacement is planned.
Gravel can also clog a drain, so a roof with a lot of loose stone near a scupper is a drainage problem waiting to happen. Where a roof has been recovered more than once, the added weight of wet material on a ponded section can stress the deck, so we look underneath where we can reach it and note any sag or rusted flutes before anyone proposes another layer.
Keeping the Plies on Paper
For each section we log plies, surfacing, last inspection date, blister and crack condition, flashing condition, repair count and an estimated service range. A replacement answers to the state's 2021 International Building Code, which took effect July 1, 2022 with exceptions, and to ASHRAE/IES 90.1-2013 on commercial energy.
That file feeds our roof condition reports and our roof asset management schedule. The record also states what each section would cost to leave alone another year, in terms of the repair line and the risk of interior damage, so the asset manager can weigh a patch against a renewal at budget time. Flood coat thickness and gravel coverage are noted by section too, since both change how long the surface will protect the felts.
Repair, Recover or Replace
Minor defects are patched with compatible felts and flood coats. A sound BUR may take a coating or a roof recover overlay, while wet insulation or too many layers call for tear-off. Replacement proceeds by section: remove the old plies, repair the deck, install tapered insulation and cover board, build the new system, flash walls and curbs and set new edge metal.
Owners often compare the option with modified bitumen roofing and TPO roofing, and leaks that follow a wall are tracked through flashing failure repair. We serve downtown Tuscaloosa and the rest of the city. On an operating building, each section is dried in the same day, temporary protection goes on every opening at the end of the shift and the owner's contact receives the sequence in writing. Weather checks come before the roof is opened because hot asphalt cannot be applied to a wet surface.
Commercial Roofing Questions
What does a core cut tell you on a BUR?
The number of plies, the condition of the felts and whether the insulation is wet.
Is gravel necessary on a built-up roof?
It protects the bitumen from sun and traffic, though cap sheets and coatings can replace it. Gravel adds weight and can block drains, so the choice depends on the deck and the wind exposure.
Can a built-up roof be recovered?
Yes, when insulation is dry and the deck can carry the added layer.
Why do BUR blisters matter?
A blister signals trapped moisture or air between plies, and a broken one lets water in. Small intact blisters may be monitored and marked on the roof plan, while a cluster over a deck joint usually points to a larger problem.