TPO roofing for Alexandria condo, apartment and mixed-use roofs

Which Alexandria roofs are TPO candidates

Census figures for 2020 to 2024 count about 80,800 housing units in the city, a median build year of 1974, and the 1970s as the largest single decade of construction. Low-slope sheet usually comes up on:

• Garden-style and mid-rise condo buildings from the 1960s and 1970s, some with a big flat roof, a parapet and a handful of drains.
• Mixed-use and office buildings around Carlyle, Eisenhower Avenue and the Potomac Yard redevelopment, where the roof carries rooftop units and the foot traffic of service crews.
• Small commercial buildings, for example along Duke Street or Seminary Road, where the roof is low-slope with one or two units on curbs.
• Rear flat sections on rowhouses in Old Town and Parker-Gray, small enough that rubber or TPO would both work. Our EPDM page covers those.

A steep visible slope, such as slate facing an Old Town street, is the wrong job for single-ply. That is a metal or slate question.

Read your roof, then pick the next step

• Water still standing two days after rain. Fix the slope or add a drain first. The trade's yardstick is no ponding 48 hours after rain, and a new sheet over a pond only hides it.
• Soaked insulation, or two old layers. No recover. Virginia's residential code rules out covering a wet roof or one with two applications already, so the roof comes off to the deck.
• Kitchen or lab exhaust landing on the membrane. Check the maker's chemical statement for that exact sheet, and look at PVC as the usual alternative.
• A condominium roof. The association decides. Gather the roof drawings, repair records and reserve study entry first.
• A building in the Old and Historic Alexandria or Parker-Gray district. The Board does not review flat roofs, but staff still review visible roofing of 25 square feet or more.

A condo or apartment re-roof, in sequence

1. Paperwork first. Get roof drawings, repair history and the reserve study line from the manager, since Virginia law has condominium boards study capital components at least every five years.
2. Roof survey. We walk the drains, flashing and curbs, then use a moisture survey to find wet insulation before anyone writes a scope.
3. Scope and approvals. Ask the Permit Center whether the job needs a permit, a registered design professional, or neither.
4. Tear-off and deck. Wet layers come off, and soft deck is replaced and photographed before it is covered.
5. Insulation and sheet. Polyiso board is the common pairing. The sheet is fastened or adhered to the maker's method, welded, and flashed at walls and curbs.
6. Close-out. Welds are probed, drains are cleared, walk pads go where crews walk, and the board gets the photo set.

Two typical TPO projects in Alexandria

A 1970s condo building off Duke Street

The building has about 40 units over four stories, with a flat roof of roughly 8,000 square feet. Top-floor owners report ceiling stains after heavy rain, and the old roof shows open seams along the parapet and a ring of standing water around one drain. We would begin with a moisture survey and bring the board a map of wet and dry zones. The likely work is a tear-off of the wet areas, tapered insulation to move water to the drains, a 60 mil sheet and welded wall flashing.

A two-story office building off Seminary Road at Quaker Lane

The low roof is about 3,500 square feet with four rooftop units on curbs, and technicians cross it every quarter. Worn paths run between the units and one curb has a patched seam. We would propose an 80 mil sheet, whose lab puncture figures are higher though never a promise, plus walk pads along the service route, new curb flashing and a drain check.

Who has to say yes in Alexandria

Alexandria is an independent city, so the Department of Code Administration and its Permit Center at 4850 Mark Center Drive handle building permits, through the online APEX portal. Fairfax County has no role inside the City. The City's permit page files multi-family buildings of three or more units under Commercial and prints no roofing threshold. Call Code Administration at 703-746-4200 with the address and scope.

Virginia's state building code exempts replacing 100 square feet or less of roof covering in any building. Its unlimited exemption is written for the one- and two-family and townhouse groups, which usually leaves a larger multi-unit or commercial roof outside it, and the Permit Center has the final word. In the two historic districts, older City policy also called for a permit above 100 square feet of roofing, so confirm that with Code Administration.

Some addresses that say Alexandria, Huntington for example, sit in unincorporated Fairfax County, and Potomac Yard straddles the Arlington line. The parcel decides, not the mailing address. For Fairfax parcels our county permit guide applies.

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Where we look at flat roofs near Alexandria

Our office is in Reston, and we take calls across Northern Virginia, DC and the Maryland suburbs. Most of our work is residential, so a very large roof may be better served by a commercial specialist. The service area list shows the rest of the map.