If Your Roof
Water Clears Within Two Days of Rain
Drains run clear and the deck pitch already moves water off the roof.
Start WithNew Membrane Over the Existing Slope
DrainageTapered Insulation
Flat Roofing ยท Paducah, KY
Paducah Flat Roofing Contractor
See Whether Your Flat Roof Needs Tapered Insulation, New Membrane or Both
Bring in a Paducah flat roofing contractor to fix ponding with tapered insulation and new drains, then cover the roof with welded or taped membrane.
MembraneTPO or EPDM
- Ponding fixed with tapered boards
- New drain bowls and retrofit inserts
- Wet boards replaced down to the deck
- Welded or taped membrane on top
Does This Flat Roof Need More Than a Membrane?
As a Paducah flat roofing contractor, we check how water leaves the roof before deciding what goes on top of it.
If Your Roof
Rings of Water Around Each Drain
Insulation near the drain bowl has crushed, or the bowl sits higher than the roof around it.
Start WithTapered Sumps and New Drain Bowls
If Your Roof
Water Trapped Behind Rooftop Units
Wide curbs block the flow and leave ponds on their uphill side after storms.
Start WithCrickets Behind the Curbs
If Your Roof
Pitch Enough to Shed Water Off the Eaves
Panels on a framed slope would carry water to gutters instead of interior drains.
Start WithMetal Over a Flat Roof
Ponding and Drainage Problems on Flat Roofs
A flat roof ponding fix in Paducah starts with knowing why the water sits. The first condition below shows up on most roofs that hold water.
Most Common
Ponding Over Crushed Insulation
Foot traffic around rooftop units and long stretches of standing water crush the insulation boards, and each low spot grows as it collects more water. The added weight loads the deck, and the membrane under the pond wears faster than the rest of the field.
Usually Means: Replace crushed boards with tapered insulation under new membrane.
Clogged or Rusted Drain Bowls
Leaves, grit and rust choke the strainer, so water stacks up across the roof after every storm.
Ponds Behind Wide Curbs
Rooftop units set across the slope dam water on their uphill side when no cricket splits the flow.
Scuppers Set Too High
Water has to rise above a scupper opening in the parapet before it drains, leaving a shallow pond along the wall.
Leaks Near Low Spots
Ceiling stains under the middle of a bay point to a pond sitting on a weakened lap above.
Drainage Fixes From Your Paducah Flat Roofing Contractor
Most flat roof work pairs a drainage fix with new membrane. These are the drainage options we install on low-slope commercial roofs.
| Fix | What It Does | Where It Fits | Watch For |
|---|---|---|---|
| Tapered insulation | Slopes the surface toward each drain | Roofs with ponds between drains | Raises edge and curb heights |
| Crickets | Splits water around obstacles | Behind wide curbs and between drains | Must tie into the tapered layout |
| New drain bowls | Replaces rusted or broken drains | Cracked bowls or clamping rings | Plumbing review for interior piping |
| Retrofit drain inserts | Lines an old drain from the roof side | Drains with intact piping below | Slightly smaller opening than before |
| Overflow scuppers | Gives water a second way off | Parapet roofs with interior drains | Set above the primary drain level |
Tapered insulation is cut to a layout drawn from the roof measurements, so every board slopes toward a drain.
Benefits of a Flat Roof That Drains
Getting water off the roof changes how the membrane wears, what happens below it and how often you pay for repairs.
On The Roof
Dry Surface Between Storms
Tapered boards and crickets move rain to drains and scuppers, so the membrane dries out between storms instead of sitting under a pond.
Less Load on the Deck
Every inch of standing water adds weight over the bays, and draining it keeps that load off the joists and steel deck.
Inside The Building
Fewer Drips at Mid-Bay
Ponds sit over the middle of each bay, so moving water to the drains ends the leaks that show up over warehouse aisles.
Drains That Keep Up With Storms
New bowls and strainers carry heavy storm runoff into the piping, so water stops backing up around the drain and under the sheet.
For Planning And Budget
Membrane That Wears Evenly
A roof that drains wears at the same rate across the field, instead of failing early in the low spots and forcing patches there.
Slope Built In Once
Building slope into the insulation during a replacement avoids tearing up a newer membrane later just to add tapered boards.
Water Still Standing Days After the Rain?
Call us and tell us where the water collects. Checking the drains and the insulation under the pond shows whether a drain fix or tapered insulation is needed.
Paducah Flat Roofing Work, Step by Step
A flat roof job starts with where the water goes, then builds the slope and the membrane on top of it.
Inspect Your Roof
LEVELSWe map the ponds after rain, check every drain bowl and strainer, cut cores in low spots, and note which curbs block the flow of water.
Lay Out the Taper
LAYOUTRoof measurements become a tapered insulation plan that slopes each area toward a drain, with crickets drawn behind wide curbs and between drains.
Open and Dry In
TEAR-OFFCrushed and wet boards come off down to the deck one section at a time, and each section is closed watertight before the end of the day.
Build the Slope
TAPERTapered polyiso goes down in staggered layers with cover board on top, and new drain bowls or retrofit inserts are set at the low points.
Membrane and Flashing
SHEETTPO or EPDM covers the new slope, curbs are flashed to the raised height, and overflow scuppers go in above the primary drains.
Membranes That Go Over a Rebuilt Flat Roof
Once the slope is in, one of these goes on top, or a single leak gets a repair if the field is still dry.
TPO Roofing
Welded white TPO over the tapered boards suits air-conditioned buildings and roofs crowded with curbs.
TPO roofing in PaducahEPDM Roofing
Taped black or white EPDM covers large unheated buildings with wide sheets and few seams.
EPDM roofing in PaducahCommercial Roof Repair
A single leaking lap near a drain on an otherwise dry roof gets a matched repair instead of a new membrane.
Commercial roof repairBest Flat Roofing Answers for Paducah Buildings
Questions about ponding, drains and membranes on flat commercial roofs, with the short answer on each row.
How long can water sit on a flat roof before it is a problem?
About two days
Water that is still there about two days after rain counts as ponding. It loads the deck, wears the membrane faster under the pond, and finds any weak lap inside its footprint. A few small puddles that dry quickly are normal on a low-slope roof, while wide rings that stay put call for a drainage fix.
What is tapered insulation on a flat roof?
Sloped boards to drains
Tapered insulation is polyiso cut into boards that change thickness across their width, laid out so the roof surface slopes toward each drain. It adds slope without rebuilding the structure and goes in during a replacement, under the new cover board and membrane. Crickets made from the same tapered pieces split water around wide curbs.
Which membrane works on a flat commercial roof?
TPO or EPDM, mostly
TPO and EPDM cover most flat commercial roofs around Paducah. White TPO with welded seams fits air-conditioned offices and stores, and black EPDM with taped seams fits unheated storage. Roofs near grease fans or process vents need a sheet checked against the maker's chemical chart first, and PVC often comes up there.
When should a flat roof drain be replaced?
Cracked bowl or ring
Replace the drain when the bowl is cracked or rusted through, the clamping ring no longer holds the membrane, or the strainer is missing and debris keeps clogging the pipe. A retrofit insert lined in from the roof side works when the piping below is intact. Drain piping changes inside the building also go through plumbing review.
Can a flat roof be converted to a sloped metal roof?
Yes, with framing
Yes. Light-gauge steel framing fastened to the building structure builds a new slope above the old membrane, and metal panels then shed water off the eaves. An engineer checks the added load, rooftop units get new curbs, and gutters go on the new eaves. The framing plan goes through the local building office first.
Schedule a Paducah Flat Roofing Contractor
Send us photos of where the water sits after rain. We will check the drains and slope and give you a free estimate for the flat roof.