Flat Roof Leak Repair in Minneapolis
A leaking flat roof rarely fixes itself, and in Minneapolis a small leak can get worse fast once water freezes in seams and under flashing. When we handle flat roof leak repair in Minneapolis, we find where the water is actually getting in and fix it properly, so you’re not patching the same spot every spring.
We repair EPDM rubber, TPO, PVC and modified bitumen roofs on commercial buildings, apartment buildings, garages, porches and home additions. If your roof has a leak, a split seam, a puncture or water sitting in low spots, we can help.
Call (888) 657-0348 or request a free estimate. We respond within 24–48 hours.
Finding the Leak
Why Flat Roof Leaks Are Hard to Track Down
On a sloped roof, water usually shows up close to where it got in. On a flat roof it’s different. Water can enter at a seam or flashing, run along the deck or through the insulation, and drip through the ceiling many feet away.
That’s why patching the spot directly above the ceiling stain often doesn’t work. We start at the most likely entry points, which are usually the details rather than the open field of the roof:
- Seams and laps between membrane sheets
- Flashing at walls, parapets and roof edges
- Curbs around HVAC units, skylights and hatches
- Pipe boots and other penetrations
- Roof drains, scuppers and gutters
- Punctures from foot traffic, dropped tools or storm debris
On larger roofs, infrared or capacitance moisture surveys can show where insulation under the membrane has gotten wet. Small test cuts then confirm what’s going on before any repair plan is finalized.
Common Problems
Flat Roof Repair in Minneapolis: Problems We Fix
Open or Failing Seams
Seams are the most common leak point on single-ply roofs. EPDM seams are glued or taped, and older seams can dry out and peel. TPO and PVC seams are heat-welded, and a poor original weld or physical damage can open them up. We clean, prep and re-seal or re-weld seams based on the membrane type.
Punctures and Tears
Foot traffic from HVAC service, dropped tools, hail and wind-blown debris can puncture a membrane. Punctures are usually simple to fix with a properly sized patch, as long as the insulation underneath is still dry.
Flashing Failures
Flashing is where the roof meets anything vertical: walls, parapets, curbs and pipes. Membrane flashing can shrink, pull away or crack with age, and edge metal can loosen. We repair or replace flashings and terminations so water can’t get behind them.
Ponding Water
NRCA defines ponding as water that stays on a roof more than 48 hours after it rains. Ponding speeds up membrane wear, adds weight and freezes in winter. Small low spots can sometimes be corrected with added insulation or crickets during a repair; widespread ponding is often a sign the roof’s drainage needs to be redesigned.
Clogged or Damaged Drains
Leaves, debris and ice block drains and scuppers, and older drain bodies and clamping rings can fail. We clear drains, replace strainers and repair the membrane connection at the drain bowl.
Blisters and Ridges
Blisters show up most often on modified bitumen and built-up roofs, usually from trapped moisture or air. Not every blister needs immediate repair, but broken or growing blisters do. We cut out and patch damaged areas and check whether moisture is the underlying cause.
By Membrane
Rubber, TPO, PVC and Modified Bitumen Repair
Each membrane is repaired differently, and using the wrong materials can make a leak worse. Here’s how repairs work on the systems we see most often in Minneapolis.
EPDM Roof Repair (Rubber Roofs)
EPDM is a thermoset rubber membrane, usually black, and it’s common on older Minneapolis commercial buildings, garages and porches. Rubber flat roof repair uses EPDM-compatible primers, seam tape and cured or uncured EPDM patches. Proper cleaning and priming matter more than anything else, since EPDM does not weld. EPDM also has limited resistance to oils, grease and asphalt products, so it shouldn’t be patched with roofing tar.
TPO Repair
TPO is a thermoplastic membrane, usually white, with heat-welded seams. Repairs are typically done by welding a TPO patch over the damaged area with a hot-air welder. Older, weathered TPO needs careful cleaning before it will accept a weld.
PVC Repair
PVC is also thermoplastic and heat-welded, and it holds up well against grease and oils, which is why it’s used over restaurants. PVC should not come in contact with asphalt-based materials, so the repair materials have to match the system.
Modified Bitumen Repair
Modified bitumen roofs are asphalt-based sheets that can be torch-applied, set in hot asphalt, cold-applied or self-adhered, depending on the product. Repairs often involve cutting out damaged sections, sealing the edges and installing new plies of compatible material. On occupied buildings, cold-applied or self-adhered materials avoid open flame near sensitive areas.
Water Coming Through the Ceiling?
Don’t wait for the next thaw or rainstorm to make it worse. Call (888) 657-0348.
Winter Leaks
Flat Roof Leaks in Minnesota Winters
A lot of flat roof leaks in Minnesota show up during thaws. Snow melts on a sunny day, drains are still frozen, and water backs up against seams and flashings that would normally stay dry. Then it refreezes overnight and pushes those openings a little wider.
Winter leak calls are often caused by:
- Frozen or blocked drains and scuppers
- Snow drifts packed against walls, parapets and rooftop units
- Damage from shovels or snow removal equipment
- Seams and flashings already weakened over the summer
Some permanent repairs depend on temperature, because certain adhesives and primers have cold-weather limits. When conditions don’t allow a full repair, we can make a temporary repair to stop the water and come back for the permanent fix. If you need help clearing a roof, see our roof snow removal service, and for active leaks after a storm, see emergency roof repair.
Repair or Replace
When Repair Makes Sense, and When It Doesn't
We’d rather fix a roof that can be fixed. Repair is usually the right call when:
- The leaks are limited to a few spots or details
- The membrane is still flexible and well attached
- The insulation underneath is mostly dry
- The roof is not at the end of its expected life
Replacement starts to make more sense when wet insulation is widespread, leaks keep showing up in new places, or the membrane is brittle, shrinking or pulling away at the edges. Wet insulation loses its insulating value and should be removed, so a roof with large wet areas usually can’t be fixed with patches alone.
Building codes also limit re-covering. A new roof generally can’t go over an existing one that is water-soaked or deteriorated, or over a roof that already has two layers. If your roof is at that point, our page on flat roof replacement options explains membranes, insulation and drainage in detail.
Prevention
Keeping a Repaired Flat Roof Leak-Free
A good repair lasts longer when the rest of the roof is kept in shape. A few simple habits make a big difference on a flat roof in Minneapolis:
- Inspect twice a year. NRCA recommends checking roofs at least twice a year, ideally in spring and fall, and after severe weather such as hailstorms. Learn more about a professional roof inspection.
- Keep drains clear. Clean drains and scuppers in fall before leaves and ice block them.
- Limit foot traffic. Walkway pads around HVAC units protect the membrane where service crews walk most.
- Watch for ponding. Water that’s still there two days after rain is a sign of a drainage problem.
- Act on small issues. A loose seam or lifted flashing is cheap to fix now and expensive once water gets into the insulation.
How We Work
Flat Roof Leak Repair in Minneapolis: What to Expect
When you need to fix a flat commercial roof in Minneapolis, or a flat roof over a home addition or garage, the process is simple.
- Call or request a free estimate. Let us know where you see water and how long it’s been happening.
- Inspection. We check the roof surface, seams, flashings, drains and penetrations, plus the inside leak locations.
- Clear findings. You get photos and a plain-language explanation of what’s causing the leak and what it will take to fix it.
- Repair. We use materials compatible with your existing membrane and clean up when we’re done.
If we find that the roof has problems beyond the leak you called about, such as wet insulation in other areas or seams that are close to failing, we’ll show you and explain your options. You decide what gets done and when.
Our Minneapolis roofing company handles flat roof repair across Minneapolis, for both homes and commercial buildings. Whether it’s a rubber roof over a garage or a TPO roof over a warehouse, the goal is the same: find the real cause and fix it once.
Common Questions
Frequently Asked Questions
Answers to common questions about flat roof repair in Minneapolis.
Can a leaking flat roof be repaired, or does it need to be replaced?
Most flat roof leaks can be repaired if the problem is limited to a few areas and the insulation underneath is still dry. Widespread wet insulation or a brittle, shrinking membrane usually means replacement is the better option.
Why does my flat roof only leak when snow melts?
Melting snow often can’t reach frozen drains, so water backs up against seams and flashings and finds small openings. Clearing drains and repairing weak seams before winter usually solves it.
Can you repair a flat roof in winter?
Many repairs can be made in cold weather, and temporary repairs can stop active leaks. Some adhesives and primers have temperature limits, so certain permanent repairs may need to wait for suitable conditions.
Can I use roofing tar on a rubber roof?
No. EPDM rubber has limited resistance to asphalt-based products, and tar can damage the membrane and make proper repairs harder. EPDM should be repaired with compatible primers, tapes and patches.
Is water standing on my flat roof a problem?
NRCA considers water that remains more than 48 hours after rain to be ponding. Ponding speeds up wear, adds weight and turns to ice in winter, so it’s worth having checked.
How do I know what type of flat roof I have?
Black rubbery membranes are usually EPDM, smooth white sheets with welded seams are usually TPO or PVC, and granular-surfaced rolled sheets are often modified bitumen. We confirm the system during the inspection.
Get Your Flat Roof Leak Fixed
From EPDM rubber roofs to TPO, PVC and modified bitumen, we repair flat roofs on Minneapolis homes and commercial buildings. Call (888) 657-0348 or request a free estimate.
