Repairs to flat and very low-slope membrane roofs on Philadelphia rowhouses, twins and converted buildings, starting at the drainage path.
Fastest: call (833) 751-2102. Or send this and we call you back.
Flat roof repair on a Philadelphia rowhouse means finding where water stopped leaving the roof and sealing the joint it found instead. The roof is not truly flat: the city's own homeowner guide puts the fall at a quarter inch per foot toward a drain. Call (833) 751-2102 and a local roofer walks the drainage path first.
A rowhouse roof looks flat from the pavement and behaves like a shallow funnel. The Philadelphia Rowhouse Manual, the city's homeowner guide, gives a minimum of a quarter inch of drop for every twelve inches of run, all of it aimed at one low point. Repair work follows that geometry. The field in the middle of the roof is rarely where the trouble started.
Multi-floor row homes are about 70% of the city's housing by one estimate from a Philadelphia architecture-and-design body, and roughly three quarters of those are more than fifty years old. That is the roof most of this city owns, and it fails in a short list of recognisable ways rather than in a thousand.
Philadelphia Roofing sends a local roofer who treats the leak as a water path rather than a stain. Where the ceiling is wet below is where the water gave up, not where it got in. Our Philadelphia rowhouse flat roof guide sets out the same walk in more detail.
Because the edges are where the membrane stops. Contractor and inspector guidance consistently names parapet flashing, drain and scupper seams and ponding water as the trouble spots on this roof type. The open field is one continuous sheet; every edge is a joint between two materials that move at different rates.
Think about what a parapet is doing. It is a short masonry wall standing in the weather on all sides, with the roof membrane turned up its inside face and a coping or cornice on top. Rain hits it from the street side, sun heats it, and the wall and the sheet expand by different amounts. The seal at the top of that upstand is the hardest working inch of the roof.
Drains are the other half of the story. A roof drain may pass through the cornice or the parapet as a scupper and join a downspout on the outside of the building, or the water may run to a gutter along the facade, which the city's guide notes is more common at the rear. Either way the outlet is a hole in the waterproofing, trimmed with a flange or a sleeve, and it sits at the exact point where the most water collects.
By elimination, in order of likelihood. The roofer clears and tests the outlet, checks every termination and penetration, then looks at the field. On an attached house the water may have entered several metres from the stain, because it runs between the membrane and the deck until it finds a gap in the boards.
This is why a single patch aimed at the wet ceiling so often fails. The sheet above the stain can be perfectly sound while the actual entry point is a lifted lap near the parapet, with the water travelling the length of a joist bay in between.
A wet test settles it. Water is introduced at one suspect detail at a time, lowest first, and someone watches the ceiling below between each stage. It is slower than guessing and it is the difference between a repair that holds and a second visit. If the entry point cannot be isolated this way, roof leak repair covers the longer tracing job, including cases where the water is coming from a wall rather than a roof.
Most roof replacements need a permit, filed by the contractor through Licenses and Inspections. Whether a small repair needs one is a question for L&I about the specific address and scope. The city does operate an EZ permit, a permit without plans, and says most applications are processed in five business days.
Scope is what decides it, so describe the work honestly when you ask: a sealed seam and a cleared drain is not the same filing as stripping a covering back to the deck. Larger and commercial buildings can fall under different city rules, and L&I answers for the address.
There is a sequencing detail worth knowing if a repair turns into something bigger. For minor permits the L&I inspection comes after the old roofing has been removed and the new material is on site, and the new membrane or coating should not be installed until that inspection passes. A roofer who understands that builds it into the schedule instead of discovering it mid-job. Our guide on roof permits in Philadelphia goes through it.
An agreement with the neighbours and a sealed party-wall detail. On a continuous row the membrane terminates against a wall that belongs to two houses, and contractor guidance is clear that the termination must be sealed so water does not migrate next door. Access often crosses someone else's roof too.
Practically, that means telling the adjoining owners before the crew arrives, and it means the roofer looking at both sides of a shared parapet rather than only the half you pay for. Water that gets into the top of a party wall does not respect the property line, and a leak that appears in your neighbour's back bedroom can have started on your roof.
Access is the other shared problem. Narrow streets, no driveway and nowhere obvious for a skip mean materials and tear-off have to be planned around the kerb and the pavement. On stepped blocks such as those above the Schuylkill in Manayunk and Roxborough, adjoining roofs sit at different levels, which changes where a ladder or a hoist can go.
Stay off a wet or ponded low-slope roof. The surface is slick, a soft patch gives no warning before the deck flexes, and a parapet is a knee-high wall rather than a guard rail. Never stand on the parapet or lean over it to clear a scupper, and keep off the roof entirely in wind. Inside the house, move what is under a wet ceiling and leave a bulging plaster ceiling alone, because it can let go all at once. Call (833) 751-2102 and let a roofer with the right footing and fall protection go up.
The roofer starts at the high side and follows the fall to the low point, clearing the drain bowl or scupper and noting whether the water can actually leave. A roof that cannot drain will keep producing leaks wherever it is patched.
The edge of any standing water is marked so its extent is recorded. A shallow pond that covers a seam loads that joint continuously, which is a different problem from a single puncture in dry membrane.
Every place the membrane stops is checked: the parapet and cornice edge, the party-wall upstand shared with the neighbours, vent collars, old hatch curbs and any disused penetration left from earlier work.
Older roofs here are generally built-up tar and gravel; later work is usually a modified bitumen, EPDM or TPO membrane. The repair has to be compatible with what is already down, which is one reason a roof with three generations of work on it is slower to quote.
The patched detail is wetted or the drain run is flooded so the fix is proven while the roofer is still on the roof. The ceiling below is checked again afterwards rather than left to the next storm to judge.
The most common call. A lap, a drain flange or a membrane edge has opened and water is tracking under the sheet. The repair is local and the roof stays in service, provided the surrounding membrane is still sound and the drainage has been corrected.
Water sitting on a roof usually means a blocked or undersized outlet, a sagging deck or a saddle that has flattened. Sealing a seam under a pond buys time; restoring the fall or the outlet capacity is what stops the next one. What is possible is judged on the roof.
A roof with isolated damage over a dry deck is a repair. A roof with wet insulation across several bays, split membrane in open field and no usable fall is a candidate for flat roof replacement, and a roofer should say so rather than sell a run of patches.
Most flat roof repair calls are scheduled the same day when a technician is free, and you approve the price before any work starts.
The housing stock sets the job. Roughly four in ten homes in the city date from before 1940 by an older Census-based analysis, and the continuous brick rows of South Philadelphia, Queen Village and Fishtown are where low-slope membrane work is routine rather than specialist.
Weather here is a wind and rain story rather than a hail one. Tropical-storm remnants and summer straight-line wind lift membrane edges and flashing; the National Weather Service recorded a line of microbursts with gusts of 60 to 70 mph crossing West and South Philadelphia and the Lower Merion area inside about half an hour. Winters bring some snow most years in widely varying amounts, and a drain that freezes is a drain that ponds.
Not every roof in the service area is flat. Twins in West Philadelphia, Germantown and the Delaware and Montgomery County townships often carry pitched slate or shingle, which is a different trade on the same house type. In Camden and the New Jersey townships the permit comes from the municipality rather than Philadelphia.
Clearing, resealing and re-detailing the outlets that take water off a low-slope rowhouse roof.
Sealing the upstands, copings and party-wall terminations where a Philadelphia rowhouse membrane meets masonry.
Stripping and rebuilding a low-slope roof on a rowhouse, twin or loft conversion, with the drainage and parapet details redesigned rather than reused.
Tracing a leak to its actual entry point on flat or pitched roofs, then repairing the detail that failed.
Not sure if you're covered? Check your ZIP code.
No public price list exists for roof work in Philadelphia, so this guide does not print a dollar figure.
Most Philadelphia rowhouse roofs look flat but slope toward a drain, with a minimum fall of a quarter inch for every foot.
Emergency protection can go on in bad weather, but a lasting membrane repair needs a dry, clean surface to bond to. The usual sequence is to get the water controlled now and return for the permanent detail once the roof has dried out.
It is a warning rather than a leak. Standing water loads the seams underneath it continuously and shows that the fall or the outlet is not working. On a roof built to drain at a quarter inch per foot, a pond that is still there days later means something has changed.
That depends on the deck and the membrane around the repair, not on the patch. No lifespan figures for roofing materials are published here because the sources found did not support them. A roofer should tell you what condition the surrounding sheet is in and whether further patching is good money.
Yes. A gravel surface generally indicates an older built-up roof, and the stone has to be swept back to expose the membrane before anything is bonded. It also makes a puncture harder to find, because the damage is under the ballast rather than visible on top.
That is between the owners and any association involved, and it is worth settling before the work rather than after. What a roofer can do is document which side of the wall the water is entering and what detail failed, which is the information both households need.
Yes, across the service area, including the older attached rows in Conshohocken, Chester and Upper Darby and the larger membrane roofs on converted commercial buildings. Permits in those places come from the township or borough rather than Philadelphia L&I.