Flat Roofing

Flat and low-slope roofs are common on row houses, additions, garages, porches and commercial buildings throughout New York, New Jersey and Pennsylvania. They are not truly flat; a good low-slope roof is built with a slight pitch so water reaches the drains instead of sitting on the surface. Most flat-roof problems come back to drainage, seams and flashing, and that is where we focus.

Flat roofing systems we install

• TPO: a single-ply white membrane with heat-welded seams. It reflects sunlight, which can help keep the top floor cooler in summer.
• EPDM (rubber): a durable, flexible membrane that handles temperature swings well and is straightforward to repair.
• Modified bitumen: a multi-layer, asphalt-based system that stands up well to foot traffic, common on row houses and smaller buildings.
• Roof coatings: on a roof that is still structurally sound, a coating can seal minor cracks and extend its life without a full replacement.

The right system depends on the building, how the roof is used, the existing layers and your budget. We will explain the trade-offs rather than push one product.

Common flat roof problems

• Ponding water that stays on the roof long after rain stops
• Blisters, bubbles or splits in the membrane
• Open seams and lifted edges
• Failed flashing at parapet walls, skylights, hatches and HVAC curbs
• Clogged drains, scuppers or gutters

How we approach a flat roof project

Inspection. We check the membrane, seams, flashing and drainage, and look for wet insulation, which can hide under a roof that looks fine from above.

Plan. If the roof can be repaired, we quote the repair. If it needs replacing, we explain whether a recover over the existing roof is allowed and sensible, or whether a full tear-off is needed.

Drainage first. Where water ponds, we address it with tapered insulation, added drains or crickets, because a new membrane over the same drainage problem will fail the same way.

Installation and detailing. Seams, corners and penetrations are where flat roofs leak, so we spend the time on them. Every curb, pipe and edge is flashed properly.

What affects the cost

• Roof area and the number of penetrations, units and drains
• Whether old layers and wet insulation must be removed
• The membrane system and insulation thickness
• Access to the roof and how materials get up there

Keeping a flat roof healthy

A quick inspection in spring and fall, and after major storms, catches most problems early. Keep drains and scuppers clear of leaves and debris, and avoid unnecessary foot traffic on the membrane. We can set up a regular inspection for commercial properties.