Roofing

Flat Roof Replacement in Johnstown, PA

We replace flat roofs on porches and additions across Johnstown and the Greater Johnstown area using EPDM and modified bitumen systems suited to Laurel Highlands winters.

Call (814) 992-6091 Request a callback

✓Mon-Fri 9am-9pm
✓Roof Replacement & Repair
✓Johnstown, Cambria & Northern Somerset Counties

Request a Callback

Tell us about your roof problem and a local technician will call you back.

Flat roofs on porches and additions in Johnstown often fail from standing water after heavy snowmelt, ice dams that form at eaves during freeze-thaw cycles, and wind-driven rain that penetrates seams on ridge-top homes. Older steel-mill-era homes in neighborhoods like Moxham, Kernville, and Westmont frequently have plank decking that sags under repeated snow loads, while additions in Richland Township and Geistown see granule loss and seam separation from summer hail and thunderstorms. Our crews inspect by lifting existing layers to check for wet insulation, rotted plank decking, and inadequate slope that traps water against brick chimneys and walls.

We begin every flat roof project by documenting drainage patterns around the Conemaugh River valley and noting how tight hillside access in places like Cambria City or along PA-271 affects material staging. Preparation includes removing all existing membrane and underlayment down to the deck, replacing damaged sections with new OSB where plank boards have shifted, and installing new drip edge plus ice and water shield at valleys and perimeters. Installation follows with fully adhered EPDM or torch-down modified bitumen, sealed step flashing at adjoining walls, and new pipe boots to restore a watertight surface that withstands strong ridge winds.

Local conditions in the Laurel Highlands demand balanced ventilation and proper counter-flashing around chimneys common on early-1900s homes in Hornerstown and Roxbury. Our crews pay special attention to transitions where flat sections meet steep-pitch slate or shingle roofs, ensuring no gaps that allow ice dam leaks into living spaces below. Work on these compact lots requires careful protection of narrow streets and neighboring properties while maintaining attic ventilation balance to reduce future condensation issues.

Technician insight

In Johnstown, the thing that catches most people out with flat roof replacement is hidden rot on plank decking under multiple old layers on steep hillside additions; the tight access in neighborhoods like Cambria City or along Menoher Boulevard means we often have to hand-carry materials and stage carefully around narrow streets and neighboring homes.

Westmont Porch Addition Leak

Water entered a kitchen ceiling after repeated ice dam formation on a flat porch roof in Westmont. We found saturated insulation and shifted plank decking beneath two older membrane layers. Our crews removed everything to the joists, re-sheathed the low-slope section, and installed a new fully adhered EPDM system with improved edge flashing.

Flat Roof Replacement Services We Offer

✓EPDM Flat Roof Replacement

Full removal and replacement of EPDM membrane on porch and addition roofs to restore drainage and resist ice dam formation common in Johnstown winters.

✓Modified Bitumen Re-Roofing

Torch-down modified bitumen installation over existing or new decking to handle heavy snow loads and wind exposure on Cambria County homes.

✓Porch Addition Flat Roof Repair

Targeted seam repairs and flashing upgrades on flat porch roofs to stop leaks caused by freeze-thaw cycles in neighborhoods like Westmont and Geistown.

✓Deck Assessment and Re-Sheathing

Inspection and replacement of plank or deteriorated decking beneath flat roofs to prevent sagging under snow weight in older Johnstown frame houses.

✓Flashing and Transition Detailing

New step flashing, counter-flashing, and valley work where flat roofs meet steep-pitch sections on homes in Kernville and along US-219.

How it works

1
Site Assessment
We examine the flat roof, deck condition, drainage, and transitions to walls or chimneys while noting access limits on steep Johnstown lots.
2
Layer Removal and Deck Prep
Our crews tear off existing membrane and underlayment, replace damaged plank sections, and install ice and water shield at critical points.
3
Membrane Installation
We adhere new EPDM or modified bitumen with sealed seams, updated flashing at chimneys and walls, and proper edge detailing.
4
Final Drainage and Ventilation Check
We verify slope, clear gutters and downspouts, and confirm attic ventilation balance before completing the project.

What's Included in the Visit

Full Tear-Off to Deck

We remove the old membrane, insulation, and fasteners down to the wood deck. No layovers, no trapped moisture. On most Johnstown homes, that means one dumpster and a full day of tear-off before anything new goes down.

Tapered Insulation for Drainage

We install polyiso insulation in a tapered layout so water flows to the drains or scuppers. On dead-level roofs, we add crickets behind chimneys and at wall intersections.

New Membrane and Seams

Heat-welded TPO, adhered EPDM, or torch-applied modified bitumen, depending on your roof and budget. Every seam is probed and every penetration gets a proper boot or pitch pocket. We do not rely on caulk to seal anything structural.

Flashing and Edge Metal

New drip edge, counterflashing at walls and chimneys, and new pipe boots at every vent. Old rusted flashing is the second most common leak source on flat roofs after ponding, so we replace it rather than reusing it.

Cleanup and Magnetic Sweep

We tarp landscaping, haul every scrap of old membrane, and run a magnetic sweeper across the yard and driveway twice. Your gutters get checked for debris too. You should not be able to tell we were there except for the new roof.

Tools and Methods We Use

Moisture Meter

This tells us how much sheathing needs replacement before we open the roof, so there are no surprises mid-job.

Heat Welder and Seam Probe

For TPO membranes, we heat-weld every seam and then test it with a seam probe. If the probe catches, the seam gets redone. This is the single most important quality check on a TPO roof.

Torch Rig and Roller

For modified bitumen systems, we use a controlled torch rig and a weighted roller to set the membrane into the adhesive. This is how we get a fully bonded sheet with no trapped air pockets.

Pitch Hoist

Lifting membrane rolls, insulation bundles, and polyiso boards onto a flat roof safely. It keeps our crew off ladders with heavy loads and keeps your landscaping intact.

Magnetic Sweeper

After every job, we sweep the yard, driveway, and walkways twice for roofing nails. It is the last thing we do before we leave, and it is why our customers do not find nails in their tires.

Tapered Insulation Layout

We design the insulation layout so water flows to the drains or scuppers instead of sitting. On dead-level roofs, we add crickets behind chimneys and at wall intersections.

Conemaugh Roofing Co. — roofing in Johnstown

Good to know

Flat Roof Replacement — FAQs

Still have questions? We're happy to talk it through.

(814) 992-6091

+ How do you handle drainage on flat roofs in Johnstown?

We assess existing slope and add tapered insulation or crickets where needed to move water toward scuppers or gutters before installing the new membrane.

+ Can you replace just the membrane or do you always do a full tear-off?

We evaluate the number of existing layers and deck condition; most jobs require full removal to reach sound decking and prevent future ice dam issues.

+ What membrane types work best for local snow and wind?

EPDM and modified bitumen both perform well here when installed with proper flashing and ventilation to manage freeze-thaw cycles.

+ Do flat roof projects affect the main steep-pitch roof?

We detail all transitions carefully so the new flat section integrates with existing slate or shingle roofs without creating leak points at valleys or walls.