Good Shepherd Roofing installs, repairs and replaces flat and low-slope roofs across Gwinnett County and North Georgia. We are a licensed general contractor, licence number GCCO009698, based at 2505 2nd Ave in Dacula and trading since 2016.

A flat roof is a different trade from a shingle roof, and a contractor who is good at one is not automatically equipped for the other. This page explains the difference, the systems available, and how to choose between them.

Call (833) 477-7663 or book a free inspection.

A flat roof is not flat. Low-slope roofs are built with a slight fall so water moves toward drains, and a genuinely level roof would hold water across its whole area.

The real distinction is how they keep water out. A pitched roof sheds water by gravity and overlap: each course laps the one below, and water runs off before it can find a joint. That only works while water is moving quickly. On a shallow pitch, water moves slowly, wind drives it sideways and even uphill, and any joint at the level of the surface becomes a way in.

So a low-slope roof is waterproofed differently. Instead of overlapping pieces, it uses a continuous membrane with sealed seams, so the surface resists water even when that water is slow to leave. This is why building codes set a minimum slope below which lapped materials such as shingles may not be used at all.

TPO

A thermoplastic single-ply membrane, usually white, with seams that are heat welded so the sheets fuse into one continuous surface. The most common choice on commercial low-slope roofs, and available with rated solar reflectance. See TPO roofing for the detail.

PVC

Also thermoplastic and also heat welded, with better resistance to grease, oils and chemical exposure. This is the system specified over restaurant kitchens and some process buildings, where a TPO roof would degrade around the exhaust.

EPDM

A synthetic rubber, and a thermoset rather than a thermoplastic, which means it cannot be heat welded. Seams are made with adhesive tape or bonding adhesive. Long field record, good in cold weather, and traditionally black although reflective versions exist.

Modified bitumen

Asphalt sheets modified with polymers for flexibility, installed in one or more plies by torch, hot asphalt, cold adhesive or self-adhesion. More robust underfoot than single-ply, which suits roofs with regular maintenance access.

Built-up roofing

The oldest established system: alternating layers of bitumen and reinforcing felts built up on site, finished with gravel or a mineral cap sheet. Heavy, durable, and still widely found on older commercial buildings.

Coatings and restoration

Not a replacement but a renewal. A fluid-applied coating cures into a seamless membrane over a roof whose substrate is still sound. See commercial roof coatings.

There is no single best system. The right one depends on the building, and these are the questions that actually decide it.

Does the roof hold water? If drainage is poor and ponding is likely, that rules out some materials and points toward those that tolerate standing water.

How much foot traffic will it take? A roof with rooftop plant that gets serviced monthly needs more puncture resistance than one nobody walks on.

Is there chemical or grease exposure? Kitchen exhaust is the common case, and it is the clearest argument for PVC over TPO.

Does reflectivity matter? On a large conditioned building in the Georgia summer, a reflective membrane affects cooling load. Reflectance and thermal emittance are rated separately, and rated initial values decline as the surface weathers.

What is already there? The existing substrate constrains what can go over it, and whether a re-cover is permitted at all depends on how many coverings the roof already carries.

We will tell you which of these apply to your building rather than recommending the same system to everyone.

More low-slope roofs fail because of water that did not leave than because of any defect in the membrane itself.

Ponding water increases the structural load on the deck. It accelerates degradation of several membrane types. It collects dirt and encourages growth, which destroys reflectance on a cool roof. And it turns any small breach into a continuous leak rather than an occasional one, because there is always water sitting on it.

Positive drainage is designed in. Slope comes either from the structure or from tapered insulation cut to fall toward the drains. Crickets and saddles are formed behind curbs and between drain points so water is not left standing against an obstruction. Drains and scuppers are sized for the roof area and the local rainfall intensity rather than by habit.

If your roof ponds after every storm, that is the thing to fix. Replacing the membrane without correcting the drainage reproduces the same failure on a newer surface.

Most low-slope leaks are repairable, and they nearly always originate at the terminations rather than in the field: perimeter edges, parapets, drains, and every penetration for pipework and equipment.

Repair method is dictated by the membrane. TPO and PVC are hot-air welded, EPDM uses tape and primer because it cannot be welded, and bituminous systems are repaired as originally installed. See commercial roof repair.

Flat roofing is not only a commercial problem. Plenty of houses in this area have a low-slope section: a porch or portico roof, a rear addition, a dormer, a garage, or a modern flat-roofed design.

These are frequently the leakiest part of an otherwise sound house, because they were built as an afterthought and sometimes covered with shingles on a pitch far too shallow to carry them. The fix is a proper low-slope membrane, correctly detailed where it meets the pitched roof and the wall above it.

We do this work. If you have a flat section over an addition that keeps leaking, that is a recognised problem with a known answer.

Warehouse and distribution, retail and strip centres, office and medical office, churches and schools, apartment and multifamily, restaurants and light industrial, and residential low-slope sections.

Good Shepherd Roofing holds Georgia general contractor licence GCCO009698, issued as a General Contractor Company licence. We have operated since 2016 and we are based at 2505 2nd Ave, Dacula, GA 30019.

We work on flat and low-slope roofs throughout Gwinnett County, including Snellville, Duluth, Lawrenceville, Dacula, Buford and Braselton, and across North Georgia including Johns Creek, Chamblee, Roswell, Winder, Auburn and Athens.

What is the difference between a flat roof and a low-slope roof?

In practice, none. Low-slope is the technical term and it is more accurate, because a roof in this category is never truly level. It is built with a slight fall so water moves toward the drains.

Which flat roofing system lasts longest?

It depends on the building rather than the material. Service life is governed by drainage, foot traffic, chemical exposure, installation quality and maintenance. A well-drained and maintained roof of almost any system outlasts a ponding, neglected one of a supposedly better system.

How long does a flat roof last?

Manufacturers publish expected lives and warranty terms that vary by system and by membrane thickness. What actually determines it on your building is drainage and maintenance. We will give you a realistic view of the roof you have during the inspection.

Why does water sit on my flat roof after it rains?

Either the slope was never adequate, the structure has deflected, or the drains and scuppers are blocked or undersized. Ponding is worth correcting rather than living with, because it loads the structure and magnifies any small breach.

Can a flat roof be repaired, or does it have to be replaced?

Most low-slope leaks are repairable, because they originate at edges, drains and penetrations rather than in the middle of the membrane. Replacement is indicated where insulation is saturated across large areas, seams have failed widely, or the deck has deteriorated.

Do you install flat roofs on houses as well as commercial buildings?

Yes. Porch and portico roofs, rear additions, dormers and garages often have a low-slope section, and these are frequently the leakiest part of an otherwise sound house.

Call (833) 477-7663 or book a free inspection. We will survey the roof and tell you what it needs, including whether it needs anything at all.