EPDM roofing in Vienna, VA: the storm record and the flashing material at each penetration

Counting the Vienna rows by what they describe

NOAA publishes every severe-weather report it logs as a Storm Events row. For this page the rows were counted again from the yearly files for 2016 through 2026, using Fairfax County rows whose place label contains Vienna. That label is a NOAA place name, not the Town boundary. There are 15, and they fall in eight separate years, with none in 2022 or 2023.

Source: NOAA NCEI Storm Events bulk files, Virginia, Fairfax County zone rows, opened October 20, 2026. Counts are our arithmetic. NOAA gives wind magnitude only for wind and hail rows, and marks type EG as a wind estimated gust.

The one row that names a roof

The EPDM Roofing Association FAQ discusses puncture exposure, in its case from birds, and names a reinforced membrane over a rigid substrate, pavers, and corner detailing such as double flashings. It points the reader to the membrane maker. It does not address falling limbs, so treat it as an example of how corners are discussed, not a Vienna rule.

Cured and uncured flashing: where each goes

The generic EPDM roofing guide covers the membrane. This page stays with the pieces that surround it. A federal model specification, UFGS 07 53 23 (August 2025), draws a clear line between two flashing materials.

Two things follow. A scope that says only "EPDM flashing" has not said which of the two goes at a given detail. And the specification is a federal document: it shows how the trade names its materials, but it does not bind a private owner.

Following one flashing detail upward

The specification describes a wall or curb flashing from the deck up. Read as a sequence, it gives an owner a list of questions to ask about a drawing.

1. Fasten at the turn. The membrane is mechanically fastened at penetrations, at the base of curbs and walls and where it turns an angle greater than 1:12, with fasteners at most 12 inches apart. The fasteners are then covered by a fully adhered layer.
2. Reinforce corners. Every corner and angle transition is reinforced with uncured membrane, following the membrane maker.
3. Run the base flashing up. It runs not less than 8 inches above the roofing surface, is fully adhered and is seamed as the roof membrane is.
4. Terminate the top edge. A termination bar goes at most 12 inches on center, with sheet metal flashing installed over it.
5. Line the metal. A membrane liner overlaps the top of the base flashing at curbs, parapets and expansion joints, under the sheet metal parts.

Seam tape is not a given at flashings. The specification notes that tape can be difficult to apply to flashing conditions, and names lap splice adhesive or self-adhering flashing membrane as the alternatives there.

Pipe, curb, corner, drain: how the specification words each

Pipe seal

Prefabricated pipe seals sit in the specification list of flashing items, and cured material and prefabricated accessory flashings are to be used to the extent the maker recommends. A formed collar is the sort of shaped detail where uncured sheet is allowed.

Curb

A prefabricated curb option calls for a flange at least 4 inches wide for attachment to nailers and a height of at least 8 inches above the finished membrane. The curb is anchored to the nailer and flashed with EPDM flashing material.

Set-on item

Pipe supports and similar accessories sit on the membrane over a reinforced membrane or walkpad layer, and are not mechanically secured through the membrane into the deck.

Corner

Reinforced with uncured membrane, as above. The industry FAQ separately suggests double flashings at corners exposed to puncture.

Drain

Field seams are to be avoided within 24 inches of the drain, and the membrane is cut to within three quarters of an inch of the clamping ring rim, so drainage capacity is not reduced.

The flood rows in Vienna are about roads, so they say nothing about a roof drain. If water is a concern on your roof, the EPDM Roofing Association FAQ lists drains in low areas, crickets and saddles, and tapered insulation as its drainage tools.

What the industry says about aged EPDM and new flashing

The EPDM Roofing Association is a trade group that represents manufacturers of EPDM roofing, so its bulletins are industry statements. Bulletin 102 says repairs are made with pressure-sensitive products on a membrane that has been cleaned and primed, that an existing membrane can be cut for new ductwork or conduit and flashed with new material, and that new pressure-sensitive flashings can in many cases be added over the originals or after removing them.

Bulletin 101 goes further: it says flashing in a new penetration in an aged membrane "works as well as the day it is installed." That is the association claim, and its own repair page says the bulletins do not replace design services by a qualified roof consultant or architect. Ask for the maker written statement on adding to a roof of your age and condition.

Lines for an EPDM flashing scope

• For each pipe, vent, curb and drain: the flashing named as cured, uncured or prefabricated, with its thickness.
• Which corners and angle transitions get reinforcing pieces, and of what material.
• Base flashing height, termination bar spacing and what metal sits over it.
• How the membrane is fastened at turns, and what covers those fasteners.
• The membrane maker detail number for each penetration type, in writing.
• Whether the work is a repair or a replacement, since the county permit lists and the state exemption speak to both in different words. Read the Vienna roofing guide for the Town and county paths.

Fairfax County lists roof repairs among permit items and exempts small amounts of roof covering on its no-permit lists, and state rule 13VAC5-63-80 exempts replacing 100 square feet or less. Neither list uses the words flashing, curb or pipe seal, so ask Land Development Services before you decide. To talk through a Vienna EPDM roof, Book a phone consultation, and see the flat roof page, commercial roofing, materials and services for related guides.