Water that is still standing in a shallow pool two days after the last rain or melt is the clearest warning a flat roof gives. In West Jordan, UT, where winter snow gives way to freezing nights and a slow spring thaw, that pool usually has one of a few causes: a drain bowl blocked with debris, a scupper set too high in the wall, a sump that has settled below the surrounding membrane, or a stretch of roof that was never sloped quite enough to reach its outlet. Each has a different fix, and telling them apart takes a walk with a level, a camera and a hose.
Drainage work means everything that moves water off the roof: drains, scuppers, gutters on low-slope buildings, crickets that steer water around obstructions and the ponding corrections that make them work. Done right, the roof sheds melt within a day or two. Done wrong, or not done, every other repair on the roof is working against standing water.
Follow the water: the diagnostic walk
We begin the walk after a rain or melt when possible, since standing water draws the map for us. Stains, silt lines and a dull film on the membrane show where water sat. We measure the depth at the low points, note how far from the drain they are and follow the slope toward the outlet with a level. If the slope runs away from the drain, the pool is a design or deflection problem and no amount of clearing will cure it.
We then check every outlet: the strainer, the drain bowl, the clamping ring, the connection to the membrane and the line below, which we flush with a hose to see whether water leaves cleanly. Scuppers are checked for height against the membrane surface, for blocked throats and for the splash zone on the wall below. Everything is photographed and logged by roof section in the inspection file.
Snowmelt path: why drains fail in cold weather
Winter snowfall and freezing periods recur in the Salt Lake City airport normals. They match a familiar failure pattern in drainage. Snow melts on the sunny part of the roof during the day, runs toward a drain, and refreezes in the strainer or the pipe at night. The next day's melt has nowhere to go and backs up behind a parapet, under flashing or into a seam.
Drain bodies can also lift when water freezes in the line, breaking the seal at the membrane. The fix begins before winter: clear every strainer, flush lines, check that drain clamps are tight and replace cracked bowls. After a heavy snow, we look first at the drains and scuppers because they decide whether the melt leaves quietly or finds its own way in. A snow and ice damage repair starts with drainage for that reason.
Scuppers, gutters and downspouts
On roofs that drain through the wall, the scupper is the outlet, and its height decides how much water can stand behind the parapet. A scupper set an inch or two above the membrane leaves a permanent pool along the wall. A throat narrowed by sealant or debris reduces flow, and a downspout choked with ice sends water back through the scupper. The correction is sometimes as simple as clearing and lowering the opening, and sometimes a rebuilt scupper with new flashing and a larger collector box.
Where the building uses gutters, we check hangers, joints and slope, and make sure downspouts discharge away from the foundation and the walk. The edge metal, coping and gutters that frame these outlets get checked in the same visit, so a repaired scupper is not left joined to a failing wall cap.
Ponding correction: when clearing is not enough
When a drain is clear and water still stands, the roof surface itself has to change. Options start with adding a drain at the low point, which works when the plumbing can be reached. Tapered insulation can re-slope a section so water runs to an existing outlet, and a cricket, which is a small ridge built behind a curb or unit, steers water around the obstruction. In some cases a section of deck has sagged and needs structural attention before any roof work.
Each option has trade-offs. A new drain requires interior access and a building permit may apply; tapered insulation raises the roof surface and affects wall flashing heights; crickets add material and seams. The right choice depends on the measured depth, the roof's age and whether a new insulation layer is already planned. Chronic standing water that has already stressed the membrane calls for ponding water roof repair alongside the drainage fix.
What standing water does to a membrane
Water that stays on a roof for days speeds aging. Dirt collects in the pool, algae and mildew grow, seams under the pool stay wet and some membranes soften or lose adhesion. Freezing water in a pool lifts and cracks at seams. Wet insulation below a long-standing pool holds the moisture and loses insulating value, which a moisture scan shows as a dark patch under the pond.
We map the pool areas on the roof plan and, if the insulation may be wet, run an infrared moisture survey before choosing a fix. Draining a pool without addressing wet insulation below it leaves a problem that will show up again as a stain on the ceiling.
Permits, code and sizing
Drain work that changes the plumbing or the roof's structure can involve the building department. Drainage provisions, including secondary or overflow outlets where parapets could trap water, are checked against the 2024 International Building Code that Utah put into effect on July 1, 2026, with its state and local amendments. We check the requirements before proposing a change and state in the scope whether a permit is expected.
Sizing also matters. A replacement drain or scupper has to carry the water from the roof area it serves, and the existing outlet may be sized for a different roof than the one now in place. The scope records the area served and the outlet size so the plan can be reviewed.
Where the work happens
Drainage work matters on a low-slope roof anywhere in the city's commercial, service and office areas, including the Redwood Road and 7800 South core. On a roof with several sections, each section has its own outlet, which makes the walk longer and the log more useful. In West Jordan, the same crew handles scheduled drain maintenance and emergency calls when water is entering the building.
Commercial Roofing Questions
How long can water stand on a flat roof before it counts as ponding?
A common working rule is that water still standing a day or two after rain has stopped is ponding and needs a cause. We measure depth and time as well, so the finding is not a guess.
Can a blocked drain be cleared without a roofer?
A strainer can be cleared by maintenance staff on a safe roof. Flushing the line and checking the bowl seal are better done during a roof walk, where a failing connection can be seen.
What is a cricket and when is it used?
A cricket is a small sloped ridge built behind a curb or unit so water flows around it instead of pooling. It is used where the existing slope leaves water trapped behind equipment.
Does a new drain mean cutting into the ceiling?
Often it needs interior access to run or connect the pipe. We confirm routing and tenant impact before proposing a new drain.
Will a scupper that is too high cause leaks?
It leaves a permanent pool along the wall, which stresses the flashing there. Lowering or rebuilding it is a common fix.
Show us where the water stands
Tell us where water appears, when it appears and how the roof is reached. We will walk the roof, measure the low spots and flush the lines, then explain what must be confirmed before a repair line or schedule is set.