Metal drip edge installation

[RICHARD TAN]

Codeman,

Metal drip edge installation instruction, I have found many drip edge installation defect. I have search google and yahoo without success for installation instruction.

[Jerry Peck - Codeman]

Hi Richard,

The following is from the Florida Building Code, Residential. (underlining is mine)
- SECTION R905
- - REQUIREMENTS FOR ROOF COVERINGS
- - - R905.2 Asphalt shingles.
- - - - The installation of asphalt shingles shall comply with the provisions of this section.
- - - - R905.2.8 Flashing.
- - - - - Flashing for asphalt shingles shall comply with this section.
- - - - - R905.2.8.6 Drip edge.
- - - - - - Provide drip edge at eaves and gables of shingle roofs. Overlap to be a minimum of 3 inches (76 mm). Eave drip edges shall extend ½ inch (13 mm) below sheathing and extend back on the roof a minimum of 2 inches (51 mm). Drip edge at eaves shall be permitted to be installed either over or under the underlayment. If installed over the underlayment, there shall be a minimum 4 inch (102 mm) width of roof cement installed over the drip edge flange. Drip edge shall be mechanically fastened a maximum of 12 inches (305 mm) on center. Where the basic wind speed per Figure R301.2(4) is 110 mph (177 km/h) or greater or the mean roof height exceeds 33 feet (10 058 mm), drip edges shall be mechanically fastened a maximum of 4 inches (102 mm) on center.

Most of your Central Florida area will have a basic wind speed of between 110 mph and 110 mph, however, you do have some areas which exceed 110 mph.

There is also this, the Roofing Application Standard (RAS) No. 115.
- ROOFING APPLICATION STANDARD (RAS) No. 115
- - STANDARD PROCEDURES FOR ASPHALTIC SHINGLE INSTALLATION
- - - 5. Metal Accessories
- - - - 5.1 All metal accessories shall be in compliance with Section 1517.6 of the Florida Building Code, Building and RAS 111.
- - - - 5.2 Eave and gable drip metal vertical face shall be a minimum of 1½ inches and shall extend down not less than ½ inch below the sheathing or other member immediately contiguous thereto. In all cases, the deck flange shall be not less than 2 inches in width. Where required, a continuous clip (hook strip) shall be installed in compliance with RAS 111.
- - - - 5.3 Eave and gable drip metal shall be joined by a lapped of a minimum of 4 in. and the entire interior of the joints shall be coated with approved flashing cement. Eave and gable drip metal shall be fastened with minimum 12 gauge annular ring shank nails at a maximum spacing of 4 in. o.c. The nails shall be manufactured from similar and compatible material to the termination profile. All composite materials shall be fastened with nonferrous nails. All metal profiles shall be installed in compliance with RAS 111.
- - - - 5.4 Valley metal shall be a minimum 16 in. wide rolled or preformed material of thickness in compliance with Section 1517.6 of the Florida Building Code, Building. Valley metal shall be set over the underlayment, or over an optional 18 in. sweat sheet. Fasten valley metal with minimum 12 gage by 1¼ in. annular ring shank roofing nails of similar materials 12 in. o.c. 1 in. in from each exterior edge. The entire edge of the flange shall be sealed, covering all nail penetrations with flashing cement and membrane. All horizontal laps shall be a minimum of 6 in. and shall be fully embedded with approved flashing cement. No nails shall be permitted in the center of the valley.

Not much for me to add, most of the above is pretty specific.

Codeman

[RICHARD TAN]

I have found many metal drip edge install flush with fascia board, is this correct? In the old day we used to install 1"x 2" mailer on the fascia board, so the metal drip edge is away from the fascia board to prevent capillary or wicking of water into the wood fascia.

[Jerry Peck - Codeman]

Hi Richard,

Yes, that is the 'old way' from when things were 'done to basic construction knowledge' knowing that water would run back and rot the fascia out if that were not done, however, as the codes have progressed (and I use that not meaning that the requirements have progressed but that one code edition has progressed into the next and then to the Florida Building Code based on the Standard Building Codes, then progressed to being based on the International Codes) many things which were 'basic construction knowledge' were discontinued by codes and manufacturers who found a 'lower minimum standard', which is, after all, what codes are "minimum standards", and the lowest defensible standard gets accepted, even though construction history has shown that something more worked.

But that is another soap box to get up on and I try to avoid getting on those soap boxes here as I try to keep 'my opinion' out of the discussions here and relate the code and construction requirements as written and specified, even though many have been, regrettably, reduced over time.

This is from the 2004 Florida Building Code, Residential with 2006 Revisions.
- R905.2 Asphalt shingles.
- - The installation of asphalt shingles shall comply with the provisions of this section.
- - R905.2.8.6 Drip edge.
- - - Provide drip edge at eaves and gables of shingle roofs. Overlap to be a minimum of 3 inches (76 mm). Eave drip edges shall extend ½ inch (13 mm) below sheathing and extend back on the roof a minimum of 2 inches (51 mm). Drip edge at eaves shall be permitted to be installed either over or under the underlayment. If installed over the underlayment, there shall be a minimum 4 inch (102 mm) width of roof cement installed over the drip edge flange. Drip edge shall be mechanically fastened a maximum of 12 inches (305 mm) on center. Where the basic wind speed per Figure R301.2(4) is 110 mph (177 km/h) or greater or the mean roof height exceeds 33 feet (10 058 mm), drip edges shall be mechanically fastened a maximum of 4 inches (102 mm) on center.

As shown, there is no longer a requirement for that spacer, which we used to call 'shingle molding' and other terms. The 'old way' was to have a minimum 1/2 inch space between the back of the drip edge and the fascia, and the typical method to accomplish that was to install 1x2 firring strips behind the drip edge, with the drip edge extending below the 1x2 firring strips by 1/2 inch minimum. Doing it that way *just made sense* to everyone, but, yes, it did take a little more time and material which also meant it cost more to do it that way.