TPO roofing is a single-ply thermoplastic membrane, 60 mils thick on a deck, rolled across the rooftop and heat-welded at each lap until the sheets fuse into one continuous skin. No exposed fasteners through the field means fewer places for water to seep in.
Summer is why it pays off here. A dark tar and gravel assembly baked into a rooftop can read 160°F on a humid July afternoon in Trenton, and that heat drives through the insulation into the space below. White TPO reflects most of it.
Winter runs the other direction. Snow sits on a low-slope roof, melts at the warm eave, then refreezes into an ice dam that backs meltwater up under the flashing. Welded seams hold that ponding better than a glued lap does.
TPO is not the right answer on every building. A pitched roof over Victorian rowhomes from the 1800s, a mid-century bungalow, or a post-war twin home sheds water with shingles for less money, and any roofer who tells you otherwise has the wrong product.
When the existing cover is one layer and the deck reads dry on a moisture meter, a recover over the old sheet saves a dumpster and a day of labor. Saturated insulation changes that call.
We tear off to the decking when the substrate is wet, because a new sheet laid over damp insulation blisters within a season.
We split the work the way most buildings are built: residential roofing on the pitched shingle and slate planes, commercial roofing on the flat and low-slope ones.
Roofing services overlap at the gutters, the flashing, and the wall ties, which is where a contractor who only works one half of the trade gets into trouble.
Roofing materials get picked by pitch, drainage, and how the building is used, not by what is on sale. Here is what we put on the low-slope side.
- TPO sheet from Carlisle SynTec or GAF EverGuard is heat-welded at the lap and probed by hand before we call a seam closed.
- EPDM rubber installs with adhesive or seam tape, which suits small canopies and awning covers.
- PVC membrane resists grease and chemical exhaust, so it pays off over a restaurant kitchen vent.
- Modified bitumen goes down in torched or self-adhered layers and takes foot traffic better than thin single-ply.
- A built-up roof of tar, bitumen, and felt plies still covers plenty of buildings here and can be recoated while the plies are dry.
- Firestone, Johns Manville, and Versico supply the TPO and EPDM sheet we install, with 15- to 30-year no-dollar-limit warranties available on commercial systems.
- A coating over sound modified bitumen adds reflectivity and buys years before replacement, at a fraction of the cost.
On any membrane job, these are the pieces we open up and check.
- Parapet walls take counter-flashing at the roof edge, and that joint is where wind-driven rain gets in first.
- Scuppers and drains move water off a flat roof; a clogged one leaves ponding water sitting on the membrane.
- Coping caps the parapet and needs a fresh sealant bead whenever the old caulk dries and pulls away.
- Drip edge at the eave pushes runoff clear of the fascia so water cannot wick back under the sheet.
- A soffit vent and a ridge vent work as a pair, and a powered attic fan helps a low-pitch roof that cannot vent on its own.
- Step flashing gets reset wherever a roof plane meets a sidewall, which is where most leaks we open up began.
- Chimney flashing, apron flashing, and boot flashing around a pipe boot or vent boot need new metal once the old pieces corrode.
- A skylight or dormer interrupts the field course, so the flashing around it gets checked at every roof inspection.
- Ridge caps, the hip and ridge lines, and the rake along a gable or verge take the most wind uplift on the roofline.
- Valleys and the sheathing under a mansard or gambrel overhang collect debris, and standing water rots the decking.
- Gutter and downspout runs get re-hung after a tear-off, since a downspout that dumps at the foundation undoes your waterproofing.
- Mastic and roof cement patch small failures in a pinch, but a proper repair uses new flashing and a sealed lap.
- Snow guards and roof anchors go on roofs where ice slides, and an anchor gives a crew something legal to tie off.
Below the membrane, structure and fastening decide whether the new roof lasts.
- A truss, rafter, joist, or ridge beam that has sagged changes the estimate, because a new membrane follows the deck it sits on.
- Plywood or OSB sheathing that has gone soft gets replaced before anything rolls out, and we check with a pry bar, not a glance.
- Roof deck panels and the substrate under the membrane get checked for moisture content, since damp decking makes a new roof fail early.
- On a metal building, purlins carry the panel, and battens or counterbattens hold a standing-seam panel off the deck.
- Fasteners matter more than buyers think: an overdriven screw or a short nail gives the wind a place to start.
- We use ring-shank nails and correct-length fasteners so the sheet is held at the right depth along every lap and edge.
- A self-adhered underlayment or ice-and-water shield goes along the eave and valley before the finish layer lands.
The pitched halves of these buildings take different materials.
- Steep pitches still get asphalt shingle, and on an older rowhome that usually means architectural shingle rather than three-tab shingle.
- Historic buildings with wood shake or cedar shake get re-roofed in kind when the owner wants to keep the look.
- Slate, clay tile, and concrete tile are heavy and long-lived; they need a deck rated to carry the load.
- A metal panel, standing-seam panel, or corrugated panel works on canopies and porches where a low pitch holds water.
- Synthetic underlayment has largely replaced roofing felt and tar paper, though felt still shows up under old slate.
- Ice-and-water shield at the eave is what stops an ice dam from pushing meltwater into the house.
- Insulation and ventilation belong in the same conversation; a warm deck with no vapor barrier grows mold on the sheathing.
Jobsite setup and tools say a lot about how a crew works.
- Scaffold and ladder setup happens before the first roll comes off the truck, and every crew member ties off with a safety harness.
- Pry bars and roofing shovels strip the old cover; a nail gun and air compressor only speed up work we could do by hand.
- A roofing square and chalk line set the stagger so the field course and starter course line up.
- A torch is for modified bitumen only, and it never comes near a TPO sheet.
- Debris goes into a dumpster on site, and we run a magnet over the parking area for nails before we pull away.
Maintenance, claims, and the questions buyers ask after the quote.
- Roof maintenance tips that matter: keep drains and scuppers clear, trim overhanging branches, and walk the roof after a storm.
- Dam removal in winter is a February routine here, and we steam ice off the eave rather than chop it, because a hammer takes the flashing with it.
- Insurance claims go easier when a dated roof inspection is already on file before the storm hits.
- Energy efficiency on a commercial building starts at the membrane, and added insulation board cuts the cooling load further.
- Sustainability in roofing is mostly about not sending usable material to a landfill, which is why a recover or a coating often wins.
- Green roofing assemblies are engineered, not improvised; planted trays add load, and the structure has to be rated for it.
- Roofing technology has changed the promises we can make, since heat-welded seams and moisture scans replaced guesswork.
Our service area runs across Trenton and the rest of Mercer County, which keeps us close enough to reach a storm damage call the same day. Local expertise matters less than local response time.
A licensed and insured roofing contractor should show you the findings before the quote. We photograph the deck, mark wet insulation on a roof plan, and separate weatherproofing from a real roof replacement item.
Customer satisfaction here comes down to one thing: the roof stops leaking and nobody has to call us twice. Read the customer testimonials on this site before you read a pricing page.
Any roofing company can hand you a number. Call 877-909-0534 and we will hand you a roof estimate you can actually read, with roof repair priced line by line.
