TPO Roofing in Northern Virginia: TPO or EPDM, and Who Reads the Roof
In the Northern Virginia pages we read, the address and the number of homes in the building decide who looks at a flat roof far more than whether the sheet is TPO or EPDM. This guide sets the places side by side.
Only two of the places below name a membrane at all, and neither names TPO or EPDM. The question that changes the answer is the address, then the unit count.
- Alexandria and the City of Fairfax mention membranes. Arlington, Falls Church, Fairfax County and Reston Association do not, in the pages read.
- Alexandria and Arlington file buildings of three or more homes under commercial.
Decision aid
Who reads a flat roof in each place, and what does the text leave out?
Pages opened October 12, 2026, except rows marked carried or archived. Each row holds only for the place named.
| Place and office | What the text says about flat or membrane roofs | Names a membrane? | What it leaves out |
|---|---|---|---|
| City of Alexandria: Board of Architectural Review staff (703.746.3833) and Code Administration (703.746.4200) | Flat and low-sloped roofs are not reviewed by the Board because of their limited visibility, "in most cases", and staff may still send a project to the Board. The Board recommends light colors on flat roofs. Apartments and condominiums of three or more homes are listed under Commercial. | Yes: "single ply membrane" and "rubber membranes" appear in the lists of materials found in the districts | Any rule on color, and any roofing rule for the Residential or Commercial permit column |
| Arlington County: Permit Arlington (703-228-3800), county pages read as archived copies | The residential roof-covering table turns on decking replaced, with 256 square feet as the line. Apartment buildings of three or more dwelling units are "considered commercial per the Building Code". The commercial page lists no roof-covering row. | Not in the pages read | What a re-roof of a building with three or more homes needs |
| City of Falls Church: Code Administration (703-248-5080) | On a single-family house, replacing a roof needs no permit as long as rafters or a major portion of the decking are not replaced. The same page says multifamily and commercial requirements differ. | Not in the page read | How the multifamily requirements differ |
| City of Fairfax: Design Guidelines (Certificate of Appropriateness) and Code Administration (703-385-7830) | In all three review districts, rubber membrane or built-up roofs can be used on flat or sloping roofs that are "not visible from public areas". The sentences sit in the new-construction chapters. | Yes: "rubber membranes". TPO and EPDM are not named | Re-covering an existing flat roof, the height of a parapet, and what counts as a "significant" change |
| Fairfax County addresses: Land Development Services (703-222-0801) | The no-permit list names replacement of roof shingles and of less than 256 square feet of roof plywood, unless fire rated, such as on townhomes. The permit list names roof repairs. The commercial list exempts replacing less than 100 square feet of roof covering. | Not in the pages read | Membranes themselves |
| Reston Association design review (inside Reston only) | The roofing checklist lists 3-tab, architectural, wood, simulated shakes, metal, tile and composition. Carried from our Reston sheet of October 1, 2026. | Not in the checklist | How a flat section is treated under the covenants |
| Virginia building code, section 108.2 (every Virginia row above) | Unlimited roof-covering replacement is exempt in Groups R-3, R-4 and R-5 under a wind-speed condition, and 100 square feet or less in all groups. Group R-2 is defined as more than two dwelling units. A historic district can lead the building official to ask for a permit anyway. | Not in the text read | Which group a particular building is in, which is for the building official |
Where a text names a membrane, it sets a visibility test, not a product
Alexandria takes flat roofs out of Board review because few people see them. The City of Fairfax allows membranes where the public cannot see the roof. Neither sets TPO against EPDM.
The order to ask in
Which question settles a membrane roof first?
First: which jurisdiction owns the address?
A Falls Church mailing address can sit in Fairfax County, as Seven Corners and Bailey's Crossroads do, and a Fairfax mailing address in the county belongs to Land Development Services.
County address: use the Fairfax County and Reston rowsSecond: how many homes does the building hold?
Alexandria and Arlington treat three or more as commercial, Falls Church says multifamily rules differ, and the state code calls more than two dwelling units Group R-2. That one number can move the whole question to another page.
Third: can anyone see the roof from public land?
Alexandria and the City of Fairfax both turn on visibility. Neither defines it in the text we read.
Fourth: does a board or association have its own rule?
Reston Association's checklist does not name a membrane, and Alexandria's color advice is a recommendation.
Fifth: what will the written scope say?
Only now does TPO versus EPDM come in, as the items below.
TPO or EPDM
Which assumptions about the sheet do the local texts back up?
The City will want white TPO.
Alexandria's Board recommends light colors on flat roofs, as advice listed beside a line encouraging living roofs. No other place in the table says anything about color.
EPDM is rubber, so a "rubber membrane" line covers it.
The words appear in the Alexandria sheet and the City of Fairfax Guidelines, and neither names EPDM, TPO or PVC. Ask staff how your product is classed, with the data sheet in hand.
The color of the roof tells me which sheet it is.
The single-ply trade association says sheet membranes come in black, white and a large variety of other colors. The data sheet identifies the material, not the shade.
On paper
What should a TPO or EPDM scope say in writing?
- Name the sheet by its standardThe 2021 International Building Code table of single-ply materials lists EPDM under ASTM D4637 and TPO under ASTM D6878, with PVC under D4434. Ask for the standard on the data sheet rather than a trade name or a color.
- Say how the seams are made and checkedA trade-library abstract describes TPO, PVC and KEE sheets as thermoplastic, which can be fused with heat. EPDM, a rubber, is joined with adhesive or tape. An older library abstract says many EPDM roof problems have involved lap seams, so ask how seams are made and who inspects them.
- Settle the color and who approves itWrite the color into the scope and name who agreed to it: the owner, the condominium board or the association.
- Ask who looks at the roof afterwardsThe single-ply trade association advises inspecting low-slope roofs twice a year and after any major storm.
Your address
Which page covers the place you own in?
- AlexandriaBAR sheets and permit page
Flat roofs and the color question. Read TPO roofing in Alexandria and EPDM color in Alexandria, or the Alexandria roofing page.
- ArlingtonTwo county permit pages
The residential table against the three-or-more-homes rule: TPO roofing in Arlington and the Arlington roofing page.
- Falls ChurchThe City's no-permit sentence
A rule written for houses: TPO roofing in Falls Church and the Falls Church roofing page.
- City of FairfaxDesign Guidelines
Can the street see the roof: flat roofs in the City of Fairfax and the Fairfax roofing page.
- RestonCounty permits, association review
Condominium and townhouse roofs: EPDM roofing in Reston and the Reston roofing page.
For how these roofs are built, drained and repaired, read the flat roof guide, or compare every material on the materials page.
FAQ
Questions about TPO and EPDM across Northern Virginia
Does any Northern Virginia office say TPO is allowed or banned?
Not in the pages we read. Alexandria's sheets list single ply membrane among roofing found in its districts, and the City of Fairfax Guidelines name rubber membranes. No page names TPO or EPDM.
Is a white membrane required anywhere in this table?
No page here requires it. Alexandria's Board recommends light colors on flat roofs. The other places say nothing on color in the pages read, and an association may set its own rule.
Can EPDM go on a roof the street can see?
The City of Fairfax Guidelines allow rubber membrane roofs where they are not visible from public areas, and Alexandria leaves flat roofs out of Board review because of limited visibility. Neither defines visibility.
Does the number of homes in the building change the office I call?
It can. Alexandria's permit page and Arlington's residential page both treat buildings of three or more homes as commercial, and Falls Church says multifamily requirements differ. Say the unit count first when you phone.
Is a townhouse flat roof handled like a condominium roof?
Not on the pages read. Fairfax County excludes fire-rated plywood, such as on townhomes, from its no-permit allowance, and Arlington's residential page uses a townhouse as its example of fire-retardant-treated lumber. Condominium buildings sit on the commercial side.
Do the City of Fairfax Guidelines apply at a Fairfax mailing address?
Only inside the City. A county address with a Fairfax mailing city belongs to Fairfax County Land Development Services, and none of the Guidelines text applies there.
How do TPO seams differ from EPDM seams?
TPO is a thermoplastic sheet, so seams can be fused with heat. EPDM is a rubber sheet joined with adhesive or tape. Ask how a roofer makes and checks the seams, because the method follows the material.
Which standard names TPO or EPDM on a data sheet?
The 2021 International Building Code table lists TPO under ASTM D6878 and EPDM under ASTM D4637. Ask for the standard in the written scope.
Sources
Official pages used, with the date checked
- Checked October 12, 2026: City of Alexandria BAR roofing sheets for the Old and Historic District and the Parker-Gray District, and the City permit requirements.
- Checked October 12, 2026: City of Falls Church, When a Building Permit is Required; Fairfax County, when a permit is required; the City of Fairfax Design Guidelines.
- Checked October 12, 2026: Virginia building code, 13VAC5-63-80 and 13VAC5-63-210; the single-ply trade association's FAQ.
- Carried, not reopened today: the Reston Association design review application (October 1, 2026), and Arlington County's residential and commercial permit pages as archived copies dated December 30, 2025.
Talk through the next step
Talk through your flat roof with King's Roofing
Tell us the address, how many homes the building holds and what the roof surface looks like. A short phone call is the first step.
9220 Topaz St, Fairfax, VA 22031
Mon to Fri 7 AM to 8:30 PM, Sat 7 AM to 8 PM, closed Sunday