Soprema Roofing in Brockton, MA
Blisters get the blame. They are a symptom. On a Soprema modified bitumen roof in Brockton, MA, a blister means moisture or air got trapped under the sheet. The real failure is a lap, a flashing, or a deck joint that let it in. We find that first, then decide how much of the roof is involved.
Soprema makes commercial roofing in several families: modified bitumen sheets, liquid-applied membranes such as Alsan, insulation, and related accessories. Bituminous sheets are layered and lapped. Liquid-applied products are poured or rolled on and cure in place. The two behave differently, and the repair follows the system.
Check the laps and the cap sheet
A modified bitumen roof is a stack of plies. The top sheet takes sun, wind, and foot traffic, and its laps are the weak line. Laps open when the roof moves, when the original bond was poor, or when the surface has aged. Water then runs under the cap and into the plies below.
We walk the laps and press them. We look for lifted edges, open end laps, exposed reinforcement, and granule loss. We cut small tests where we suspect trapped water. Granule loss near a drain tells us water has worked that spot for years.
The repair is plain. Cut out the failed section back to sound material, dry the plies, and lay new plies and a cap patch lapped over sound sheet on all sides. Set the edges with the right heat or adhesive. A patch over a wet lap bonds for a week and fails.
End laps and side laps fail differently. An end lap opens when the sheet shrinks lengthwise in cold, and a side lap opens when the deck moves under it. We note which direction a lap is opening, because the direction points to the cause. A lap that opens along a deck joint will open again unless the repair bridges the joint.
Choose torch, hot asphalt, or cold-applied with care
Bituminous sheets go down three ways: heat applied with a torch, set in hot asphalt, or bonded with cold adhesive. Torch work needs a fire watch and a clear deck. Hot asphalt needs a kettle and a trained crew. Cold-applied systems avoid open flame but need dry, warm surfaces.
Fire risk shapes the choice. An older brick building can have a wood deck and combustible details at its parapets, and we survey those before any heat goes near them. Where the fire risk stays too high, cold-applied methods or a fastened termination take the place of heat.
Weather decides the rest. Cold-applied adhesives need workable air, and Brockton has recorded minus 19 degrees. When the air is too cold we set a temporary patch, log it, and come back, and the report shows both dates.
Rebuild parapets and wall turns
Parapets are where flat roofs leak first. The sheet turns up a wall and ends at a cap. Movement, ice, and sun work that turn until the top edge pulls loose and water slips behind the flashing and down inside the wall.
We check the cap, the termination, and the wall face. Gaps in a masonry cap and hairline mortar cracks both feed water into the wall. We mend the cap first, then rebuild the flashing so it ends in a fastened termination with a sealed joint.
Liquid-applied flashing resin is a common choice at complex details such as pipe clusters and curb corners. It flows around odd shapes and cures into one continuous layer, but it needs a clean, dry, primed surface and it does not fix a wall that is letting water in behind it. We test the wall and the cap, then apply the resin.
Plan around freeze-thaw and wet snow
About 50 inches of precipitation arrive in Brockton each year, and February is the snowiest month at nearly 13 inches. Midday thaw followed by an overnight freeze opens every weak lap.
Drains settle the season. A blocked one floods the sheet with snowmelt, and bituminous sheets tolerate standing water only so long. Before the first hard freeze we clear the drains and scuppers and check each strainer.
Edges matter in wind. The city averages 14.3 mph, and loose edge metal lets wind under the sheet. Hurricane-force gusts can ride a nor'easter along with rain or wet snow, so we check fasteners and terminations ahead of a forecast storm.
Surfacing counts too. Granules shield the asphalt from sun, and bare patches age fast. Where granule loss is widespread but the plies are dry and bonded, a coating may extend the roof. Where plies are wet or splitting, a coating only hides the damage.
Handle older flat-roof industrial buildings
Brockton led the country in shoe production through the Civil War, and the shoe and leather trade ran large into the late twentieth century. In Stoughton, the legacy is older brick and flat-roof industrial buildings from its manufacturing and shoemaking years. A roof on such a building may have been recovered more than once, and layers stack, weight grows, and moisture hides.
A core shows the stack. We count the layers and read the insulation. If a roof has two or three layers, the deck may be carrying more than it should. If the insulation is wet, it comes out, because a new sheet over a soaked stack locks the damp in.
For a replacement, the governing document is 780 CMR, the state's 10th edition code, with the 2021 energy code as its base. A job in Stoughton or Brockton starts with that core, and a roof from GAF or Johns Manville gets the same treatment.
Record every cut and every wet ply
A bituminous roof is a stack, and the stack is the evidence. Each core and each cut shows the plies, the insulation, and the deck. We photograph every opening with a ruler in the frame and log it on the roof plan, and a year later the next visit starts from that log.
The record also protects the warranty. A manufacturer warranty may set conditions for repairs, notice, and approved materials, and the warranty file keeps those terms beside the cut log. On a wide roof in the Avon Industrial Park, where one Parker Drive building runs to 109,000 square feet, a log pays back. A large roof has many zones, and without a log the same wet spot gets patched twice.
Delay is priced the same way. A small lap opening lets in a little water each storm. By spring a lap repair has become a section rebuild. Each finding carries a price now and a likely price twelve months out. Dry plies and a sound cap point to repair, and wet plies across sections point to replacement.
Commercial Roofing Questions
What causes a blister?
Trapped moisture or air under the sheet, usually from an open lap or a joint. We cut it, dry it, and patch.
Do you use a torch on old brick buildings?
Only after surveying the deck and parapet for fire risk. Otherwise we use cold-applied methods.
Can I coat a modified bitumen roof?
If it is dry and sound. A core and a moisture map decide. Coating over wet plies traps the water.
How many layers is too many?
It depends on the deck. Two or three can overload a weak one. We check and report.
Why does the parapet leak first?
Movement and freezing water pull the flashing loose. Water then runs behind it and into the wall.