PVC roofing in Silver Spring, MD: a narrow fit, and a good one when it fits
Census estimates put 39.3 percent of Silver Spring homes in buildings of 50 or more units. Tall and mid-rise buildings often carry a flat roof crowded with equipment, and a few of those roofs meet kitchen exhaust. For those, PVC is worth a serious look. For most others it is not.
Three questions that point to PVC, or away from it
Does anything greasy land on the roof? A restaurant fan, a food-service vent or a cooking exhaust is the classic reason. Without it, PVC is often more membrane than the roof needs.
What is already stuck to the curbs and pipes? Old black rubberized flashing and PVC do not get along, and finding it early is the difference between a clean job and a failed one.
How many details does the roof have? Dozens of pipes, curbs and cables favor a system with factory-welded sections and ready-made boots. A simple open roof favors TPO, and a tiny porch roof favors rubber.
What touches the membrane, and what we do about it
| On the roof | The concern | Our response |
|---|---|---|
| Kitchen exhaust fan | Fats and oils settling on the sheet | Check the maker's chemical chart for that product |
| Old rubberized asphalt flashing | Plasticizer pulled out of the PVC | Remove it, or separate it with metal or a compatible sealant |
| Rooftop air handlers | Scuffs from service visits | Walkway pads along the route |
| Drains and scuppers | Water that lingers past two days | Correct fall and clear debris on a schedule |
Downtown and the buildings around it
Downtown Silver Spring has an Art Deco core, including the Silver Theatre of 1938 at 8633 Colesville Road, now AFI Silver, with 1960s and 1970s apartments and offices around it and a wave of newer buildings from the 2000s on. The Metro station opened in 1978, and the Silver Spring Civic Building at Ellsworth Drive and Fenton Street opened in 2010. Most downtown buildings are mid-rise or high-rise apartments and condominiums, so roofs there are an association or owner matter.
Across the wider place, along Georgia Avenue and East-West Highway as well as downtown, the Census counts 7,511 homes from the 1960s and six in ten homes in buildings of five or more units. Low-slope roofs on condominium and small commercial buildings are the usual fit for PVC, and a tower roof may be a job for a larger firm.
PVC facts worth knowing before you sign
PVC is a plasticized thermoplastic sheet reinforced with polyester or fiberglass, joined by hot-air welds. One maker's sheet has a gray bottom layer so an installer can see that a weld took, and weathered or dirty sheet gets a cleaner before welding. Test reports from two makers describe seams that held until the sheet itself gave way, which says the weld is not the weak link when it is done properly.
White PVC lists an initial reflectance of 0.86 to 0.87 in two makers' sheets, while a gray one lists 0.59, under the 0.65 ENERGY STAR bar for low-slope roofs. After the roof is down, one maker advises inspecting flashings, drains and termination sealants at least twice a year and after each storm. We would add a leaf cleanup to that routine, since a clogged drain leads to standing water. Guarantee terms, where offered, are the maker's and are given in writing.
Two typical PVC jobs in Silver Spring
A four-story 1970s apartment building near Colesville Road with a restaurant on the ground floor
The roof is about 70 by 100 feet, and the area around the kitchen fan has a dull, softened look. Old black flashing wraps three curbs. We would test the insulation under the fan wing, remove the rubberized flashing, and replace that wing with factory-welded PVC sections while checking whether the rest of the roof needs the same. The manager receives a section plan and photos, and the county permitting office should be asked what applies before work is scheduled.
A two-story office building off East-West Highway with a crowded roof
The roof carries four rooftop units, a dozen pipes and a satellite mount, and leaks have turned up at three of the pipe boots. There is no kitchen, so grease is not the issue; the number of details is. We would scope the work as a system with prefabricated boots, compare it with a simpler TPO plan, and tell the owner which one makes sense. If the roof can be simplified, PVC may not be needed.
PVC Questions From Silver Spring Owners
Does the restaurant under my apartment building mean the roof has to be PVC?
Not automatically. One maker calls its PVC inherently resistant to oils and grease, and another lists enhanced chemical resistance, yet resistance depends on the exact product and the exposure. Some TPO sheets also publish a restaurant-exhaust statement. We look at where the fan discharges, how much grease lands on the roof, and the maker's chemical chart before naming a membrane.
Can I keep the old black flashing around my rooftop units and replace only the field?
Not if that flashing is rubberized asphalt. One maker warns that rubberized asphalt can pull plasticizers out of flexible PVC, leaving it brittle or cracked. The fix is to remove the old flashing or separate the two with metal or a compatible sealant. We identify what is on the curbs before quoting, because that decides the scope.
Do rooftop equipment technicians need walkways on a new PVC roof?
Where a technician must cross the roof to reach a unit, walkway pads protect the sheet from scuffs and mark the safe route. Pads are laid along the path to each unit, and the building's manager can tell service companies to stay on them. Roofs with little traffic may not need many, and we decide from the equipment layout.
Our office building has only air handlers and no kitchen. Why would you still mention PVC?
A roof crowded with pipes, curbs and equipment has many details, and one maker builds factory-welded sections with prefabricated boots so fewer details are formed by hand on the roof. That is a reason to consider PVC even without grease. If the roof is open and simple, TPO or EPDM may meet the need, and we will say that.
Does Montgomery County have separate rules for re-roofing a mixed-use building?
Apartment, condominium and commercial roofs need a separate answer from the county. The county's published home improvement list is aimed at homeowners and says it omits municipality and association rules. For a mixed-use roof, the Department of Permitting Services is the place to ask what applies, and its answer should come before work is scheduled.
Who answers when you call
Reston Roof is based in Reston, Virginia, and mostly roofs houses, townhouses and low-slope sections, with some small commercial work. A roof larger than Reston Roof should take on may be better suited to a larger firm. A building inside Takoma Park, or one with a Four Corners or Forest Glen address, can bring extra steps, so give us the street first. The service area page lists our other territory.
Describe what vents onto your roof
List the fans, curbs and pipes, and tell us what the old flashing is made of if you know. Those details show whether PVC fits. Phone (571) 453-6515 or book a time.
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