9.12. Eave Conditions

Description: The details contained in this section are intended to show a variety of eave conditions and roofing materials. One key concern that is common to all eaves is the ability to withstand wind forces. This is a very vulnerable part of the exterior of a building. In many cases, it is the ability of this and other roof edges to withstand suction forces that keeps the entire roofing from being peeled off during high wind conditions.

For this reason, it is recommended that a continuous edge strip be used to secure the lower edge of eave flashing. The strip should be nailed to a secure part of the roof, fascia, or eave with nails spaced no more than 3" apart, in a staggered pattern.

The upper edge of the eave flashing, the apron, may be similarly nailed, as shown in Detail 9.12A, or cleated at 12" O.C., as shown in Detail 9.12B. In general the apron should extend a minimum of 4" onto the roof.

When designing the eave, consideration should be given to the drip line provided for water draining off the roof. This is particularly important if porous material, which is liable to stain, is used below. See Detail 9.12A, for drip design discussion. See Table 9.7A for fascia design considerations.

9.12A. Eave at Standing Seam Roofing Without Gutter

This detail shows a typical copper apron that is nailed to the roof. The apron may also be cleated as shown in Detail 9.12B. The lower end of the standing seam may also be folded down as in Detail 9.12C.

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This detail should be avoided where gutters are used, as it does not offer much protection if the gutter gets clogged, or if ice and snow prevent proper drainage.

9.12B. Typical Eave Flashing

This detail is typically used for flashing eaves of non-copper roofs. The copper flashing is extended a minimum of 4" onto the roof to form an apron. The upper edge of the apron is cleated at 12" O.C. max., or it may be nailed as shown in Detail 9.12A. The apron width should take into account local conditions such as wind, rain, snow, and ice build-up.

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9.12C. Eave at Standing Seam Roofing With or Without Gutter

This detail may be used with or without a gutter. The upper edge of the continuous apron is cleated at 12" O.C. A continuous lock strip is soldered a minimum of 4" away from this upper edge. The copper roofing is locked into the strip. The distance from the lock strip to the edge of the roof depends on the roof pitch, whether or not a gutter is used, the likelihood of water damming from ice or snow, and architectural design considerations. The lower end of the standing seam may be terminated vertically, as shown in Detail 9.12D.

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9.12D. Eave at Standing Seam Roofing With or Without Gutter

This detail is similar to Detail 9.12C, except that the standing seam roof is locked into a double fold in the apron, instead of a soldered lock strip. The lower end of the standing seam may be folded over, as shown in Detail 9.12C.

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9.12E. Eave at Batten Seam Roofing

This is a typical detail for flashing the eave of a batten seam roof. This detail is not recommended for eaves with gutters, see Detail 9.12H.

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The copper apron extends a minimum of 4" onto the roof. Its upper edge is nailed at 3" O.C., in a staggered pattern, or may be cleated at 12" O.C. max. At the edge of the roof, the apron is formed into a 3/4" lock. The pans of the batten seam roof are folded over this lock. The process is shown in Detail 8.3C. The lower edge of the flashing is held by a continuous copper edge strip.

9.12F. Eave at Horizontal Seam Roofing

The technique for flashing the eave of a horizontal seam roof is similar to that of a batten seam. The copper apron extends a minimum of 4" onto the roof. The upper edge of the apron is nailed or cleated to the wood nailer at the eave. The nailer must be wide enough to provide nailable surface under the apron or cleats. The lower edge of the roofing is locked into a 3/4" lock formed by the copper apron. The lower edge of the flashing is locked into a continuous edge strip.

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This detail also shows a decorative wood trim.

9.12G. Standing Seam Roofing and Fascia

This detail shows the eave condition where standing seam copper is used for the roof and fascia. The construction process is shown, with the completed eave on the right. This detail is not intended for use with gutters.

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This detail may also be used to construct a standing seam mansard. If the vertical dimension of the fascia exceeds 12", cleats spaced no more than 12" O.C. are required, as shown in step 1.

The bottom of the fascia pans are locked onto a continuous copper lock strip. The top of the fascia pans are bent out to form a lock. The roof pans are folded over this lock.

The two following details are intended to show how to flash the same eave with and without a gutter.

9.12H. Decorative Eave With Gutter

A decorative copper cornice is attached to the wood fascia board with cleats spaced no more than 12" O.C. The upper edge of the cornice should be positioned high enough so that it will be concealed by the gutter. Its lower edge is held by a continuous copper edge, secured to the building wall. A 3/4" drip is formed into the shape of the cornice, to ensure that water is kept away from the building facade and reduce the chance of staining. This is particularly important if the building exterior is a light color porous material.

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The apron, which is an integral part of the gutter, extends onto the roof a minimum of 6". It is attached to the roof with cleats spaced a maximum of 12" O.C. A continuous copper lock strip is soldered a minimum of 4" below the upper edge. The batten or standing seams are terminated at this lock strip, and the roofing pans are locked onto it.

The gutter is supported by brass brackets spaced a maximum of 30" O.C. in snow areas, and 36" O.C. in non-snow areas. Brass or copper straps may be required, see Gutters and Downspouts section for additional gutter information.

9.12I. Decorative Eave Without Gutter

This detail is very similar to Detail 9.12H, except that the copper apron extends down along the fascia, and locks onto the decorative cornice. This 3/4" lock forms a drip for water shedding from the roof.

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Special Conditions: For areas prone to ice and potential gutter damage, refer to a two piece gutter-apron design as noted in Section 10.2. Hung Gutters.

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