Flat Roof Repair in Hillsborough, NJ
Hillsborough Roofing repairs low slope roofs on Hillsborough homes: the flat sections over additions, sunrooms, dormers, porch roofs, and the occasional whole ranch. These are membrane systems, not shingle roofs, and they leak for their own reasons: open seams, failed wall flashing, a punctured field, or water that sits because it has nowhere to run.
Reading a low slope roof that is letting water in
Flat roofs are not flat. They are built with a small pitch, often a quarter inch per foot, and performance depends on whether that pitch still exists. Decks sag between joists, insulation compresses, and a roof that drained fine for years starts holding water.
On a low slope leak the interior stain tells us little, because water travels between the membrane and the deck before it finds a way through. So we work the roof itself: seams, terminations, penetrations, low corners, and the wall junction.
Membranes we work on and how each one fails
Around Somerset County you find three systems on residential low slope work, plus older layered roofs. The repair method follows the membrane, and the wrong material is how a patch fails inside a year.
EPDM rubber membrane
The black rubber sheet on many additions and porch roofs here. The field takes NJ sun and freeze thaw well, but the seams and adhesive at terminations are what age. Repairs use compatible primer and cover tape, not roof cement, which will not bond to cured rubber and peels off in a season.
TPO and single ply thermoplastics
A lighter single ply, usually white or gray, with seams hot air welded rather than taped. Welded seams are strong, so failures show at corners, curbs, and anywhere a detail was hand sealed instead of welded. Repair means welding in compatible material, and matching membrane type matters more than color.
Modified bitumen and older built up roofs
Rolled asphalt sheets, torch applied or self adhered, often with a granulated cap. Common on older porch roofs and flat sections recovered more than once. Blisters, open laps, and cracked flashing at the base of a wall are the usual findings. Very old felt and gravel roofs are past patching more often than not.
Flashings, curbs, and the wall junction
Whatever the membrane, where the flat meets a vertical wall is the highest risk detail on the roof. Base flashing runs up the wall, terminates, and gets counter flashed so nothing relies on sealant alone. Skylight curbs, vent pipes, and old satellite mounts are the other repeat offenders.
Ponding water and what it means for the deck
A puddle still there two days after rain is ponding, worth taking seriously before it leaks. Standing water pulls dirt into the membrane, holds the roof at a temperature the rest of the field never sees, and adds weight over a deck already sagging enough to hold it.
Sometimes the cause is a blocked drain or scupper. Sometimes it is a genuine low spot, and correcting that means tapered insulation or framing under the membrane rather than another coating on top. We will say which it is instead of chasing the symptom.
Patching, coating, or a new membrane
A sound roof with a single failure gets repaired. A clean seam, a flashing rebuild at the wall, a welded or taped patch over a puncture, and the section goes back to work. No reason to replace a membrane with good years left.
Coatings have a real place and a real limit. Silicone or acrylic over a sound membrane adds years and cuts heat load. Coating over a wet assembly or open seams just seals moisture in. When the field is brittle, several seams have failed, or the insulation is saturated, a new membrane is the honest answer and we say so rather than sell a coating that hides it.
Low slope problems we get called for most
- A rear addition ceiling staining after every heavy rain.
- A seam opened along its edge and lifted at one end.
- Standing water in the same corner days after a storm.
- A blister in the field that grows over a summer.
- Membrane pulling away from the wall above a porch.
- A puncture from a branch, or an old roof cement patch that let go.
Related roofing services
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