The flat roof over your back porch held a puddle for three days after the last storm. Or there’s a crack in the ceiling of the room addition, and you’re pretty sure it lines up with a seam up top. Flat roofing in Kansas City has a tough job: it can’t shed water the way a pitched roof does, and it has to get through hail, freezing nights and hot summers with nothing but a membrane and good drainage between your house and the weather.
You probably have two questions. Can this be fixed, or does it need a new roof? And will the next contractor actually solve it, or just smear on another patch?
APC Roofing installs and repairs residential and light commercial flat roofs. We’re GAF Certified, licensed and insured, and your inspection is free.
Where flat roofs show up on Kansas City homes
Most homes here have pitched shingle roofs, but a lot of them have a flat or low-slope section somewhere: a back porch, a sunroom or room addition, an attached garage, a dormer or a breezeway. Some mid-century homes and many small commercial buildings have flat roofs over the whole structure.
Those sections often get forgotten until they leak. They’re also the spots where shingles meet a membrane, and that transition is a frequent source of trouble if it wasn’t detailed right.
Shingles need a minimum slope to shed water. On a porch or addition with too little pitch for shingles, a membrane is the right material, not a workaround.
Common problems with flat roofing in Kansas City
Ponding water. Water should drain within a day or two of rain. If it sits longer, the roof may have sagged or the drainage is blocked or undersized. Standing water ages the membrane underneath it and adds weight.
Freeze-thaw damage. Water that gets into a seam or crack freezes overnight and widens the opening. After a winter of that, small flaws become leaks by spring.
Hail. Hail can bruise or puncture a membrane and dent the metal edges. It’s hard to see from the ground and often missed until water shows up inside.
Seams and edges. Most flat roof leaks start at seams, at the metal edge or where the roof meets a wall, a chimney or the shingled roof above.
Summer heat. UV and heat break down older membranes and sealants. A dark roof surface can get very hot by afternoon, which is hard on the material and on the room below.
Flat roof systems we install
The right system depends on your roof’s size, slope, foot traffic and budget.
- TPO is a white or light-colored single-ply membrane with heat-welded seams. It reflects much of the sun’s heat. More on our TPO roofing page.
- EPDM is a black rubber membrane that stays flexible in the cold. Its seams are taped. See EPDM roofing in Kansas City.
- Modified bitumen is a rubberized asphalt membrane in rolls, common on porches and smaller roofs.
On a small residential roof, the choice often comes down to how the roof is used, what’s under it and how it ties into the rest of the house.
Repair or replacement?
A flat roof repair usually makes sense when the leak comes from one spot, like a split seam, a lifted edge or a bad flashing at a wall, and the insulation and decking under the membrane are still dry.
Flat roof replacement makes more sense when the membrane is brittle or cracked in many places, water has soaked into the insulation or decking, or the roof has been patched again and again. If the roof holds water because of poor slope, replacement is also the chance to fix the drainage with tapered insulation, so you’re not dealing with the same puddle on the new roof.
Leaks on flat roofs can travel before they show up inside. The stain in your ceiling isn’t always under the hole, so a good inspection checks the whole roof, not just the obvious spot.
How it works with APC Roofing
- Book your free inspection. We’ll look at the membrane, seams, edges, drainage and where the flat roof meets the rest of the house.
- Get a clear, honest assessment and estimate. You’ll get photos and a written estimate with your repair or replacement options. Financing is available through Aqua Finance, Fortifi, Hearth and Home Run Finance.
- Your roof gets done and the site gets cleaned up. Many smaller flat roofs can be finished quickly, and the crew cleans up before leaving.
A slow flat-roof leak tends to soak the decking and insulation for a while before it stains a ceiling. The earlier it’s found, the more likely a repair will do.
Flat roofing questions from Kansas City homeowners
How long should water sit on a flat roof?
Ideally, not more than a day or two after rain. Water that sits longer points to a low spot, a clogged drain or poor slope, and it’s worth having checked.
Can you put shingles on a low-slope porch roof?
Only if the slope meets the shingle manufacturer’s minimum. Below that, shingles tend to leak, and a membrane like TPO, EPDM or modified bitumen is the better fit.
Do you work on small commercial flat roofs?
Yes, light commercial buildings as well as homes. For larger buildings, see our commercial roofing in Kansas City page.
Is a white flat roof worth it here?
A reflective membrane keeps the roof surface cooler in summer, which can help the room underneath. In a climate with hot summers and cold winters, it’s a trade-off worth talking through for your house.
Talk to a flat roofing contractor in Kansas City
Call 913-398-5020 or request your free estimate online, and we’ll come look at your flat roof.
What you’re after is a porch roof that drains and an addition that stays dry, so you can stop checking the ceiling every time it rains.
