EPDM Rubber Roofing in Herndon for Porches, Additions and Garage Roofs

One wide rubber sheet can cover a small flat roof with few seams. Here is where that helps a Herndon house, where it does not, and what to ask before anyone climbs a ladder.

Ask About Your Roof

A Rubber Roof for the Houses Herndon Built in the 1970s and 1980s

The Census Bureau's 2020 to 2024 estimates list 2,517 Town of Herndon homes from the 1970s and 2,016 from the 1980s. Together that is 56.1 percent of the town's 8,076 homes. A house from those decades has probably had its main roof replaced at least once. The flat parts are another story. A sunroom roof, a porch cover, a roof over a rear deck or an old garage roof is often its own surface with its own age and its own leak history, and small roofs like these are where EPDM fits.

EPDM is cured synthetic rubber. It is black unless a white version is specified, and it comes in sheets wide enough that a small roof may need no seam across the open area. It is also easy to patch. It is a poor match wherever grease or oil reaches the roof, and sharp edges or voids in the deck have to be fixed before any sheet goes down.

Talk to Reston Roof

Phone Consultation

If Your Herndon Roof Looks Like This, Here Is What Happens

  • A porch or addition roof leaks where it meets the wall. The wall flashing is the first suspect, so we open it up, check the deck beneath and rebuild the termination before judging the sheet itself.
  • A garage roof sits under a canopy of branches. Leaves in the drain are the usual cause of standing water, so we look at the drain path and the low corner before anything else.
  • The old covering has pulled away from the edges. Rubber moves a little as it ages. One maker lists a shrinkage limit of 1 percent, and that pull shows up at edges and flashings first, which is why we inspect the terminations closely.
  • Grease, cooking oil or animal fat reaches the roof. Then EPDM is the wrong choice. See PVC for roofs with kitchen exhaust.
  • The roof plane is steep and visible from the street. Rubber sheet is for low slopes. Look at metal or shingles instead.
  • Two or more layers already sit on the deck, or the roof is soaked. Then a new sheet over the top is off the table and the old layers come off first.
  • You want a welded white membrane. That is TPO territory, and we will say so.

Two Small-Roof Jobs We Would Scope

A screened porch roof on a 1980s colonial

The porch roof is about 12 by 16 feet with almost no slope. Old rolled roofing has split along the siding, and a brick chimney runs up one side. We would strip the old layer, probe the decking for soft boards, replace those and make the surface clean and smooth. One sheet would be adhered across the whole deck, with new flashing at the siding and a fresh counterflashing at the chimney. Inside, the owner sees nothing happen except, eventually, a dry ceiling.

A detached garage roof under mature oaks

This garage roof measures roughly 20 by 24 feet. Water sits at the low corner for days after a storm because a single drain keeps clogging. We would check how far the deck has sagged, correct the low spot if the structure allows, move or add a drain path, and set a rubber sheet over a clean cover. The owner sees the corner stop holding water, and gets a plain note about clearing leaves each autumn.

Aerial view of a white low-slope roof beside a shingle roof

Permit Questions That Come Up With Rubber Roofs

Inside the Town of Herndon, the Town's Building Inspections office handles roof permits. Its Re-Roof Form asks for the proposed covering, how many layers sit on the roof and in what condition, whether the work is an overlay and whether flashing needs replacing. Those are the right questions. Under the residential code a new covering over an old one is allowed only when the existing roof is dry and sound and carries fewer than two applications, so we settle it with moisture readings instead of guesses. The state code lists some roof work as exempt, but the Town publishes a dedicated Re-Roof Form, which suggests re-roofs go through its permit process, so we do not assume an exemption. We confirm with the Town before we start.

Whether a house sits near Elden Street, off Sterling Road or out toward the Fairfax County Parkway, the address decides the office. Homes with a Herndon mailing address in Oak Hill, Floris, Franklin Farm or McNair are in unincorporated Fairfax County, where Land Development Services applies. The County's own list says replacing roof shingles needs no permit, but roof repairs and large decking replacements can. A rubber membrane is not a shingle replacement, so we ask Land Development Services first. Inside the Herndon Historic District, zoning approval comes before the permit. See roof flashing repair for why wall details matter.

After a Storm, Low Roofs Take the Hits

The April 6, 2017 EF0 tornado formed just west of Herndon Parkway and tracked about three miles northeast. The National Weather Service survey found peak winds of 70 mph and mostly tree damage. On June 29, 2012, a derecho gusted to 71 mph at Dulles International Airport, the nearest weather observation point. Neither is a reason to panic about a rubber roof, but both show what low roofs near trees face: limbs, not just rain.

After a big wind, look for lifted edges, cuts and debris from the ground first. If a branch has pierced the sheet, a patch is the first step and a larger repair follows once the deck below is checked. For storm patches, see storm damage roof repair. Nearby, see our Chantilly and Great Falls EPDM pages.

Low-slope membrane roof with pipe boots, a vent and parapet flashing on a mid-rise building

Frequently Asked Questions

Will a black EPDM roof make my Herndon porch hotter in July?

A dark membrane absorbs more sun than a white one, so the surface gets hotter. How much that reaches the room below depends on the insulation and the ceiling, not just the color. White EPDM exists if you want a cooler surface, though it has to be specified. One maker argues that dark roofs help in colder climates, but that is a manufacturer claim, and our region is a mixed climate, so we treat it with caution. We will talk through your room, not a brochure.

Can one sheet of rubber cover my whole garage roof with no seams?

Often, yes, for a small roof. Makers sell EPDM in wide rolls, up to 10 feet wide with factory seam tape at one maker and up to 50 feet wide at another, so a typical garage can be covered by a single sheet with no seam across the open area. You will still have joins and terminations where the sheet meets walls, edges and penetrations, and those are where the careful work goes. Seamless across the field is not the same as seamless everywhere.

How thick should EPDM be for a roof under mature oak trees?

Makers offer 45 and 60 mil, and one adds 90 mil. Thicker sheet weighs more and resists punctures better, which matters when branches, acorns and the occasional fallen limb land on a low roof. A 45 mil sheet is the thinnest option, so under heavy tree cover we usually raise the question of 60 mil. We also look at pruning, because no sheet thickness makes up for a drain that is buried in leaves every October.

How long does an EPDM roof last, and what does the maker guarantee?

One maker states that guarantee terms of 15, 20, 25 and 30 years are available, with its thickest sheet used for the longest term. The EPDM trade association, an interested party, puts expected life for a well designed and maintained roof at 38 years. Life depends on drainage, details at the walls and edges, and whether leaks get fixed early. Any guarantee terms would come in writing.

What should I do if a storm drops branches on my EPDM roof?

Start from the ground. Look for lifted edges, cut marks or branches still resting on the sheet, and do not drag debris across the surface. Inside, check the ceiling below for new stains. If you see damage, call us and we can look at it and tape or patch a puncture as a first step. We document damage with photos for your claim, though what your insurer decides is between you and them.

Related Services

Porch or Garage Roof Giving You Trouble?

We will ask about the size, the slope and what is overhead, then plan a visit and a written scope. Phone (571) 453-6515.

Book a Phone Consultation