Flat & low-slope
Flat and low-slope roof repair in Schaumburg
Thousands of Schaumburg split-levels have a nearly flat roof over the garage or the sunken family room, and a lot of them have shingles on it, which is why they leak. We repair and replace low-slope sections with the right membrane and flash the transition to the pitched roof so it stops leaking for good.
Why split-levels leak at the flat part
The tri-level and bi-level houses built across Weathersfield, Hoffman Estates and Streamwood between 1960 and 1980 usually have one section — over the garage, the family room or a rear addition — with a pitch under 2:12. Asphalt shingles need at least 2:12 to shed water, and 4:12 to do it well. Below that, water sits, wicks up under the shingle edges and finds the nails. Add a winter of snow that never slides off and an ice dam that has nowhere to drain, and you have the most reliable leak in the northwest suburbs.
The other failure point is the transition, where the shingled upper roof meets the low-slope section. Water coming off the pitched roof lands on the flat one at volume, and if the membrane does not run up under the shingles at least 18 inches with a proper flashing, it goes under both.
What we put on a low-slope roof
EPDM rubber. A single black sheet, fully adhered, seamed with tape. The standard for residential flat roofs here for 30 years. Handles Illinois freeze-thaw well, easy to repair. $8–$14 per square foot installed on a residential section, so a 400 sq ft garage roof runs about $3,500–$5,500.
TPO. White heat-welded membrane. Reflects summer heat, seams are stronger than glued EPDM, a little more expensive. Good on larger sections and where the flat roof is visible from an upstairs window and you do not want black.
Modified bitumen. Torch-down or self-adhered asphalt sheets with a granule surface. Looks the most like a roof, tolerates foot traffic, and is the easiest match to an adjacent shingle roof in color. The two-layer self-adhered system suits the small sections on split-levels.
We do not put shingles on anything under 2:12, and between 2:12 and 4:12 we use two layers of ice-and-water shield under them. Plenty of roofs in Schaumburg have shingles on a 1:12 slope because the last roofer had a bundle left over. That is the roof we are usually replacing.
Repairs
A low-slope roof that is under 15 years old with a leak at a seam, a drain, a pipe or the transition is a repair: clean, prime, patch with the matching membrane or a cover strip, reflash the penetration. $300–$900 on most sections. Ponding water that stays two days after rain is a slope problem, and the fix is tapered insulation under a new membrane, not another patch. If the section has three patches already and the insulation under it is wet, replacement is the answer, and we quote it alongside the pitched roof so the transition is done once. See roof replacement for how the two halves are handled on the same job.
Small commercial
The same membranes go on the small commercial buildings along Golf Road, Roselle Road and in the industrial parks in Elk Grove Village. Commercial roofing Schaumburg-area businesses ask us about is mostly TPO or EPDM on strip retail and small offices under 10,000 sq ft — repairs, restoration coatings and replacement. Larger commercial is not what we do, and we will say so. The commercial roofing basics post explains what a small business owner needs to know before getting quotes.
Winter on a flat roof
Snow does not slide off a flat roof. Thirty-seven inches over a winter, compacted and refrozen, is a real load on a 1965 garage roof framed with 2x6s at 24 inches, and the melt has nowhere to go but the drain — which is frozen. We clear flat sections when a homeowner calls after a heavy storm, and we install heat cable at drains and scuppers where they freeze every year. The ice dam work on the pitched roof and the drain on the flat roof are usually the same problem: a warm attic under a cold edge.
Other roofing services
Roof Repair
Leaks at chimneys, pipe boots, valleys and skylights, wind-lifted shingles and ice dam damage — found from the attic, fixed in a morning, priced in writing.
Roof Repair →Roof Replacement
Full tear-off, decking repair, ice-and-water shield, architectural shingles or standing-seam metal, proper ventilation, permit pulled — one day on most Schaumburg homes.
Roof Replacement →Storm Damage & Insurance Claims
Hail, straight-line wind and ice damage inspected and documented for your adjuster, tarped if needed, and repaired properly. No door-knocking, no deductible games.
Storm Damage & Insurance Claims →Roof Inspection
A walk on the roof and a look in the attic, with photos and a written report that says repair, replace or leave it alone — for buyers, sellers, storms and old roofs.
Roof Inspection →Questions we get asked
Can you put shingles on a flat roof?
Not below a 2:12 pitch, and we will not. Shingles rely on gravity to shed water; on a low slope water sits under the tabs and finds the nails. The right material is a membrane — EPDM, TPO or modified bitumen — which is what we install on the low-slope sections of Schaumburg split-levels.
How much does a flat roof section cost to replace?
Residential low-slope sections run $8–$14 per square foot installed, so a typical 300–500 sq ft split-level garage or family-room roof is $3,000–$7,000 depending on membrane, insulation and how much of the transition flashing has to be rebuilt. Repairs on a sound membrane are $300–$900.
Why does my flat roof leak where it meets the shingles?
Because the membrane was not run far enough up under the shingles, or the shingles were run down onto the flat section. Water coming off the pitched roof lands hard at that seam. The fix is to extend the membrane at least 18 inches up the slope under new shingles with a proper metal transition flashing.
Need roof work in Schaumburg?
Call for a free estimate. Mon–Sat 7am–7pm.