Roof Damage Repair
Ponding Water Roof Repair in Federal Way, WA
A ponding roof starts with rain, or a hose run into the low spots, and a patient look at where the water stands. Photographs two days after a storm tell more than a walk on a dry afternoon. Water that stays on a flat roof longer than two days is not a cosmetic problem. It loads the deck, ages the membrane and finds every weak seam. In Federal Way, WA, where most of the year's rain falls from October through March, a roof that ponds has little chance to dry out.
The repair starts with the cause, not the puddle. We find the cause first and price the cure second.
How do we find out why the roof ponds?
We walk the deck with a level, a straightedge and a hose. The level shows where the roof drops, the straightedge shows where the deck sags between supports and the hose shows where water stops. Drains are checked for height against the roof plane, since a drain set above the surface leaves a pond around it. Scuppers are measured against the membrane.
Cores confirm whether the insulation under a pond is wet. A wet core means the water has been there long enough to get in, and the repair scope grows. A dry core means the membrane is holding and the cure can be limited to drainage. Each reading is photographed against a numbered plan, with the depth of standing water marked on the drawing.
Ponding rings tell the history. A faint line of dirt or algae shows where water stood in past months, even when the roof is dry. Seams inside those rings are probed with extra care, since standing water ages welds and adhesives faster than dry surface. A seam failure repair inside a pond is added to the scope, so the fix does not leave a weak lap under the new drainage.
When does ponding call for tear-off?
Tear-off is needed when wet insulation lies under the ponds or when the deck has deflected enough to need correction. The limits are marked in paint around the wet areas, and the crew leader extends them until cores come up dry. A pond that has sat for years often leaves a wet core and a stretched membrane.
If the membrane is sound and the insulation dry, the cure is lighter. A tapered insulation cricket, a new sump or an added drain can move the water without opening the roof. A roof drain and scupper correction is often the first step, and the next rain tests it. When the whole roof is flat and the budget allows, a tapered insulation and cover board scope re-slopes the roof properly.
The deck is checked before any new board goes down. A steel deck that has rusted under a long-standing pond is repaired or replaced in sections, and a deck that deflects is flagged for the engineer. Pricing these items as units in advance keeps the quantity under control. The crew leader reports a finding the same day, with a photograph.
What does a drainage fix need on site?
The crew needs access to the low areas, a spot for the crane pick if tapered board is going up, and a place for materials. At a retail center on Pacific Highway South or at The Commons, the lot stays live and staging is tight. A Woodbridge industrial building on the former Weyerhaeuser campus offers a larger yard, though truck lanes still govern.
The staging sketch marks the lay-down yard, the container and the truck route. Tenants receive a notice naming the closed entrance and the loud hours. Interior plumbing is the other access question: a new drain needs a leader, and the plumber has to reach it. The plan names who does what and when.
How do we sequence a drainage repair in the wet season?
A roof that ponds meets rain often: Tacoma sees wet weather on roughly 155 days a year, and heavy rain reaches Auburn in November and December. A drainage repair is best done in the dry months, because the membrane must be dry to bond. Winter work is limited to clearing drains and temporary measures.
When a pond threatens a ceiling in January, the crew clears the drain, siphons the pond and installs a temporary seal at any leak. Permanent re-sloping waits for a dry window. Each section is sealed by evening, and the first task the next morning is a check of the seals. The crew leader photographs the pond before and after, so the improvement is on record.
Weather forecasting matters more for a drainage job than for a patch. Rolled membrane and adhesives need dry surfaces, and a damp morning can cost the day. The forecast gets a look from the crew leader at shift start and again at midday, and the opening shrinks if a front moves up.
How do crickets, sumps and drains tie into the membrane?
A cricket is a tapered saddle that diverts water around a curb or toward a drain. A sump is a lowered area around a drain that lets water reach it. Both are covered with membrane that is welded or adhered to the existing roof at tie-ins, with termination bars where the new work meets old walls.
Probing covers each tie-in, and a water test is added where the system allows. The drain flashing is rebuilt with new membrane, a new clamp ring and sealed laps. A flashing failure repair at the drain is common, since the old flashing often split under constant water. Drainage design follows the 2021 International Building Code as Washington amended it, latest change effective March 15, 2024.
Overflow is the last detail. If the main drain clogs, a secondary outlet protects the structure from water load. Where a roof has none, we add one at the height the code and the drawing call for, and we flag it on the closeout plan so maintenance staff know it is there.
How do we prove the roof drains?
The closeout walk happens after a rain, or after a controlled flood test. We stand on the roof with the facilities contact and watch water leave. The photographs show the roof two days after rain, with no standing water beyond what the drainage design allows. The package includes the before and after depth readings, the product data and the punch list.
Owners with several buildings, such as those in Kent and Auburn, can request the same test for each. A commercial roof inspection a year later checks that the fix has held and records any new low spots.
Commercial Roofing Questions
How long can water stand before it matters?
Water standing more than two days after rain is a problem. It ages the membrane, loads the deck and finds seams, so we measure and trace the cause.
Can ponding be fixed without a new roof?
Often. A sump, a cricket or an added drain can move the water if the membrane is sound and the insulation dry.
Does a coating fix a pond?
No. A coating covers the surface and leaves the low spot. The drainage must be corrected first, then a coating can be considered.
What if the deck has sagged?
A structural engineer reviews it. We flag the sag on the walk, and the roofing scope follows the engineer's findings.
When is the best season for a drainage repair?
The dry months, since the membrane must be dry to bond. In winter we clear drains and install temporary measures until a dry window.
Send the roof plan and a photo of the pond
Send the roof plan and a photo of the standing water two days after rain. We will walk the sequence, staging and tie-ins with your team before a number goes on paper.
