Description: Gravel stops and fascias are used where flat roofs end to provide a weathertight transition between roof and wall. Fascias may have a wide variety of decorative patterns. The details shown concentrate on combined gravel stops and fascias.
Where possible, gravel stops are installed over cant strips or raised curbs. When installed on a concrete or a steel deck, a wood nailer is required. Gravel stops are, in general, about 3/4" high and formed from copper sheet 8 to 10 feet long. The copper apron extends 4" onto the roof deck. The sheets are fastened to the roof deck by nails spaced 3" O.C. The ends are lapped 3" minimum. The lapped joint on the horizontal flange is set in mastic or elastic sealant. On vertical surfaces, the lapped sheets are held together by a clevis seam, as shown in Detail 7.2J. On sloped surfaces, the clevis seam is filled with sealant before assembly.
To minimize roof membrane cracking at gravel stop apron due to differential material expansion and contraction, the maximum apron dimension is 4", whenever additional sealing stripping is required.
The maximum recommended fascia dimension is dependent on local wind conditions. Table 9.7A lists these recommendations as a function of the gauge of copper material used. The fascia dimension is the vertical dimension of the outside face of the fascia.
|Weight of Fascia Sheet (Ounces)||Velocity Pressure||Weight of Edge Strip (Ounces)|
|10-20 PSF (Inches)||21-30 PSF (Inches)||31-45 PSF (Inches)|
9.7A. Set-Back Gravel Stop
This detail shows a gravel stop installed on a wood curb, but set back from the fascia face. There are two sheets, a gravel stop and a fascia, joined on the curb by a standing seam. The lower edge of the fascia locks into a continuous edge strip, and is formed into a drip with a 3/4" lock. On a flat wall surface with no overhang, the drip should be formed at a 1-1/4" as shown, to minimize staining of wall surface below.Download CAD File
A nailable roof deck is required, otherwise wood blocking inserts must be provided.
9.7B. Gravel Stop at Fascia Board
This is a single piece gravel stop and fascia. The sheet is installed directly on the roof deck, with a 3/4" vertical projection that acts as the gravel stop. The lower edge is locked into a continuous edge strip forming a drip.Download CAD File
A nailable roof deck is required, otherwise wood blocking inserts must be provided. The horizontal base is fastened with copper nails staggered at 3" O.C.
9.7C. Gravel Stop at Deep Fascia Board
This is another example of a one-piece gravel stop-fascia. The lower edge of the fascia is held by a continuous edge strip attached to a wood nailer. The edge forms a natural drip because of the soffit provided by the overhang. The horizontal portion is fastened as described in Detail 9.7B.Download CAD File
When the fascia is 8" or more in height, waviness may be countered by forming one or more horizontal raised "V" ridges or steps not less than 1/2" high in the fascia. These ridges stiffen the flat section and should be spaced proportionally across the height of the fascia. As an alternative, consider Detail 9.7H.
9.7D. Set-Back Gravel Stop on Concrete
A separate gravel stop and fascia are illustrated. As in Detail 9.7A, the two copper sheets are joined by a standing seam cleated at 12" O.C. Since the roof deck is concrete, wood nailer is provided for securing the various elements.Download CAD File
The lower edge of the fascia is held by a continuous edge strip, which also serves as the soffit for the underside of the concrete deck and is fastened with a continuous lock strip. The horizontal portion of the gravel stop is fastened as described in Detail 9.7B.
9.7E. Gravel Stop on Raised Curb
This detail shows the typical one piece gravel stop-fascia. It is installed on a raised, canted wood curb. Its lower edge is formed into a drip. A continuous edge strip is not required if the fascia dimension is less than the recommendations in Table 9.7A. The horizontal apron portion of the gravel stop is fastened with copper nails staggered at 3" O.C.Download CAD File
9.7F. Gravel Stop at Tapered Insulation
This combined gravel stop and fascia is shown on a curb with preformed tapered insulation. The continuous edge strip at the lower edge is formed into a small soffit covering the wood blocking and nailed at 3" O.C. The horizontal apron portion of the gravel stop is fastened with copper nails staggered at 3" O.C.Download CAD File
9.7G. Gravel Stop at Concrete Cornice
This gravel stop is installed over a precast concrete cornice and joined to a copper cover. The roof side apron of the cover is locked into the gravel stop using a standing seam, cleated and anchored to a raggle in the cornice. The outer edge of the cornice cover is hooked over a one-piece continuous combination edge strip and drip edge.Download CAD File
9.7H. Two Piece Gravel Stop and Fascia
Illustrated is a two-piece gravel stop and fascia installed on a raised curb. The lower edge of the fascia is formed into a soffit and drip edge. It is held by a continuous copper lock strip which is nailed at 3" O.C., staggered.Download CAD File
The upper piece is nailed to the curb through its horizontal flange. Its lower edge is also formed into a drip.
For Additional Information:
- Basic Details, for information on seams, expansion seams, and cleats.
- Flashings and Copings - Changes in Roof Slopes, for additional information on gravel stops at changes in roof slopes.
- Flashings and Copings - Coping Covers, for more information on parapet and coping conditions.
- Table 9.7A, for recommended fascia dimensions and thicknesses.