Professional service for residential flat and low-slope roofs
While most residential roofs are sloped, many homes have flat or low-slope sections that require different roofing materials and installation methods. These flat roof areas are commonly found on porches, additions, garages, dormers, and various small structures attached to or near your home.
Flat roofs use membrane systems—typically rubber (EPDM), modified bitumen, or TPO—that create a watertight seal across the entire surface. Unlike sloped shingle roofs that rely on gravity to shed water quickly, flat roofs depend on proper drainage, quality membranes, and careful flashing details to prevent leaks.
We specialize in repairing and replacing flat roofs on residential properties and small structures throughout Jefferson County and South St. Louis County. Whether you have a leaking porch roof, a detached garage that needs attention, or a flat section on your home that's showing signs of wear, we can help.
Where you'll typically find flat or low-slope roofing on residential properties
Covered porches, front entryways, and back patios often have flat or low-slope roofs that extend from the main house. These areas are prone to leaks where they connect to the main structure.
Room additions, sunrooms, and enclosed spaces added to homes frequently use flat roofs, especially when the addition sits below the main roof line or extends from a single-story section.
Detached garages, sheds, workshops, and small storage buildings commonly have flat roofs. These structures need proper drainage and membrane maintenance to prevent leaks that damage stored items.
Dormer windows that project from sloped roofs sometimes have small flat roof sections between the dormer and the main roof. These areas require careful flashing to prevent water intrusion.
Bay windows, breakfast nooks, and small bump-outs from the main house often have flat or low-slope roofs covering them. These structures need proper waterproofing where they meet the siding.
Some single-story homes and modular homes are built with flat or low-slope roofs across the entire structure. These roofs require regular maintenance and proper drainage systems.
Issues that lead to leaks and damage on flat roofing systems
Flat roofs should have slight drainage slopes, but over time settling, sagging, or improper installation can create low spots where water pools after rain. Ponding water accelerates membrane deterioration, creates breeding grounds for algae and moss, and significantly increases leak risk. Water that remains on a flat roof for more than 48 hours after rain indicates a drainage problem that needs correction.
Flat roof membranes expand and contract with temperature changes, and over time this thermal cycling causes cracks, splits, and tears—especially in older or UV-damaged membranes. These openings allow water to penetrate the roofing system and reach the deck underneath. Small cracks can often be repaired with patches and sealants if caught early, but widespread cracking usually indicates the membrane needs replacement.
Flashing connects the flat roof membrane to vertical surfaces like walls, parapet edges, vents, and chimneys. When flashing pulls away, cracks, or deteriorates, water can get behind the membrane and into the structure. Flashing problems are one of the most common sources of flat roof leaks. Properly installed and maintained flashing is critical to keeping flat roofs watertight.
The edges of flat roofs where they meet walls, gutters, or other structures are vulnerable leak points. Roof penetrations—such as vents, pipes, or skylights—also create openings that must be properly sealed. Over time, sealants dry out, flashing degrades, and these transition points begin to leak. Regular inspection and maintenance of edges and penetrations prevents small issues from becoming major leaks.
The Key to Flat Roof Longevity: Regular inspections and prompt repairs. Flat roofs don't fail suddenly—they develop small problems that gradually worsen. Catching issues early saves money and extends the life of your flat roof significantly.
Not every flat roof problem requires complete replacement
Many flat roof issues can be effectively repaired if caught early and if the overall membrane is still in good condition. Repairs are typically appropriate when:
Complete replacement becomes necessary when the membrane or roof deck is too deteriorated for repairs to be effective. Replacement is typically recommended when:
We believe in honest assessments. If your flat roof can be effectively repaired, we'll tell you—even though replacement would be more profitable for us. Repairs that address the root problem and extend your roof's life by several years make sense financially.
However, if your flat roof is severely deteriorated or has systemic problems, patchwork repairs become a temporary band-aid that delays the inevitable while allowing more damage to occur. In those cases, replacement is the more cost-effective long-term solution. We'll explain what we find and help you understand which option makes the most sense for your situation.
Thorough evaluation to identify problems and recommend solutions
We start by visually inspecting the entire flat roof surface, looking for cracks, blisters, tears, and areas where the membrane has pulled away or deteriorated. We examine seams, flashing, edges, and all penetrations like vents and pipes. We also check for debris accumulation, vegetation growth, and signs of ponding. We take photos to document what we find so you can see the issues we're describing.
We check for moisture trapped under the membrane or in the roof deck. Moisture that's penetrated the roofing system indicates active leaks or past water intrusion that may have caused hidden damage. We probe soft spots and check for signs of rot or deterioration in the decking material underneath. Identifying moisture problems is critical because wet insulation and decking must be addressed during repairs or replacement.
We evaluate how water drains off your flat roof. We look for low spots where water pools, check that drains or scuppers aren't clogged, and assess whether the roof has adequate slope for proper drainage. Poor drainage is a primary cause of flat roof problems, so understanding your roof's drainage patterns helps us recommend solutions—whether that's improving slope, adding drains, or addressing structural issues causing sagging.
If we can access the space beneath the flat roof, we inspect from below to look for water stains, active leaks, damaged insulation, or structural concerns. Interior inspection helps us understand the full extent of any water damage and whether structural repairs are needed in addition to roof work.
After the inspection, we'll explain what we found, show you the photos, and provide a written estimate for repairs or replacement. Inspections are always free, and there's no pressure to hire us.
Missouri's severe weather—particularly hail and high winds—can damage flat roof membranes in ways that may not be immediately obvious. Understanding how storms affect flat roofs helps you know when to have your roof inspected.
Hail impacts can puncture, crack, or fracture flat roof membranes depending on hail size and membrane type. Rubber (EPDM) membranes may show puncture holes or splits. Modified bitumen roofs can develop cracks or lose surface granules. Even if hail doesn't create immediate leaks, the impacts compromise the membrane's integrity and shorten its lifespan.
After hailstorms, look for visible punctures, cracks, or areas where the membrane surface appears damaged. Check for dents in metal flashing, vents, or gutters—these indicate hail was large enough to potentially damage the roofing membrane.
High winds can lift edges of flat roof membranes, especially at seams, flashing, and perimeter areas. Once edges lift, wind-driven rain can get underneath the membrane. Storm debris blown onto flat roofs—branches, shingles from other buildings, or other objects—can puncture or tear membranes.
After windstorms, inspect for lifted seams, torn membrane edges, debris that may have caused damage, and flashing that's pulled away from walls or parapet edges. Even minor wind damage should be addressed promptly to prevent water intrusion.
If you suspect storm damage to your flat roof, having it professionally inspected helps document the damage for insurance purposes. We provide detailed photos and written assessments that can be shared with your insurance company. We can also meet with your adjuster during their inspection to ensure damage is properly identified.
Insurance companies typically have one-year deadlines for filing storm damage claims. Waiting too long to document damage can mean missing the claim window and paying for repairs out of pocket. We provide honest evaluations—if your roof doesn't have qualifying storm damage, we'll tell you.
Storm damage inspections are free, and there's no obligation to hire us even if we help document damage for insurance claims.
Flat roof leaks often cause interior damage faster than sloped roof leaks because water tends to spread horizontally under the membrane before finding a path inside. By the time you notice a ceiling stain or drip, water may have been infiltrating your structure for weeks or months.
When water gets through a flat roof membrane, it doesn't drip straight down like it does on a sloped roof. Instead, it spreads across the top of the deck or insulation layer, traveling away from the leak source. This means the visible water damage inside—a ceiling stain in your porch or addition—might be several feet away from the actual roof leak. This horizontal travel also means more area is exposed to moisture before the leak is discovered.
Flat roofs don't shed water as quickly as sloped roofs, so leaks can introduce significant moisture with each rain. This constant wetting causes insulation to become saturated and lose its R-value, wood decking to rot, and ceiling materials to stain, sag, or collapse. Mold and mildew grow in damp conditions, creating health concerns and musty odors. What starts as a small membrane crack can quickly lead to hundreds or thousands of dollars in interior repairs if not addressed.
The best way to prevent interior damage is to catch flat roof problems before they become leaks. Regular inspections—especially after severe weather or if you notice ponding water—allow you to address membrane issues, flashing problems, and drainage concerns before water gets inside.
If you notice interior water stains, drips, or musty smells in spaces beneath flat roofs, don't wait to have it inspected. The longer water infiltrates your structure, the more extensive—and expensive—the repairs become. Addressing the roof leak promptly minimizes interior damage and prevents mold growth.
Bottom Line: Flat roof leaks are not "wait and see" situations. Even small leaks cause progressive damage that worsens with each rain. If you suspect a flat roof leak, having it inspected and repaired quickly saves you money and protects your property.
Flat roofs in Crystal City and Jefferson County face challenging weather conditions that accelerate wear and increase maintenance needs. Understanding these local factors helps you appreciate why regular inspection and maintenance matter.
Missouri experiences intense rainfall during spring and summer thunderstorms, which can overwhelm flat roofs with poor drainage. Heavy rain reveals drainage problems and stresses seams and flashing. Standing water that remains on a flat roof for extended periods accelerates membrane deterioration and increases leak risk. Ensuring your flat roof has adequate slope and functional drains is critical in our climate.
Flat roof surfaces absorb intense heat during Missouri summers, with surface temperatures often exceeding 150°F. This heat accelerates UV damage to roofing membranes, causing them to become brittle, crack, and deteriorate faster than they would in cooler climates. Dark-colored membranes and those without UV-resistant coatings are especially vulnerable to heat-related aging.
Winter brings repeated freeze-thaw cycles as temperatures fluctuate above and below freezing. Water that's trapped in cracks, seams, or under lifted membrane edges freezes, expands, and widens those openings. This cycle turns small problems into larger leaks by spring. Ponding water that freezes also stresses membranes and can cause ice-related damage. Addressing drainage issues before winter prevents freeze-thaw damage.
Missouri's temperature range—from below zero in winter to over 100°F in summer—causes roofing membranes to expand and contract repeatedly. This thermal cycling stresses seams, fasteners, and material bonds, leading to separation and cracking over time. Flat roofs with proper installation that accounts for thermal movement perform better in our climate, but even well-installed membranes eventually show wear from these temperature extremes.
Local Experience Matters: We've been working on flat roofs in Jefferson County and South St. Louis County for over 9 years. We understand how Missouri weather affects flat roofing systems and know what it takes to keep them functioning properly through our climate's extremes.
If you've noticed water stains on ceilings beneath your porch or addition, see ponding water on your flat roof after rain, or are concerned about storm damage, we can help.
We'll inspect your flat roof, evaluate its condition, check for leaks and moisture damage, and explain what we find in plain language. You'll receive photos and a clear assessment of whether repairs or replacement are needed.
Call us to schedule a free inspection. We'll give you honest information about your flat roof's condition and help you understand your options—no pressure, no obligation.
Thorough Inspections
Complete evaluation with photos
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Repair or replace based on need
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Serving Jefferson County and South St. Louis County
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