1. Roof deck may be spaced or solid sheathing.

2 Tiles may be installed over any other type of roof as shown below.

a. Existing hip and ridge material must be removed.

b. Cut back existing roofing at all perimeter edges and install lum- ber to match height of adjacent roofing.

1. Install 1” X 4” vertical battens to match existing rafters.

2. Battens should be nailed with fasteners long enough to penetrate at least 3/4” into the rafter.

This is a typical grid system installed over existing wood shakes. 1 x 4” installed vertically over every rafter with a 2 x 2” installed horizontally at eave and every course line.

1. Install 2” X 2” counter battens over the vertical battens. Spacing should match the exposure of the metal tile.

2. Counter battens should be nailed with fasteners long enough to penetrate through the vertical batten.

1. To achieve a Class “A” fire rating, metal roofing may be installed:

a. over existing class “A” composition shingle roofing.

b. over wood shake or shingle roofing with an underlayment of 1/2” Gypsum sheathing with water resistant core.

c. over wood shake or shingle roofing with an underlayment of 1/4” densdeck.

d. over wood shake or shingle roofing with an underlayment of fiberglass reinforced mineral surfaced cap sheet with 1/2” foil aced fiberglass insulation installed between the bats.

2. To achieve a Class “B” fire rating, metal shingles may be installed;

a. over spaced or solid sheathing with an underlayment of 30# felt.

b. over wood shake or shingles or a non rated composition shingle with an underlayment of fiberglass reinforced mineral surfaced cap sheet.

c. over wood shakes or shingles or a non rated composition roof with one and one half inch fiberglass insulation installed between the bats.

3. Metal roofing installed in any other approved way achieves a Class “C” fire rating.

E. VALLEYS:

1. 28 gauge, 24” wide, W type metal valley with hemmed edges may be used. The tiles should overlap a minimum of 6” on each flange. Some manufacturers require a prefabricated valley to match the tile.

1. May be reused if in serviceable condition and the proper type for a metal tile roof.

2. If counter flashing is replaced, it may be fastened to the chimney with con crete nails and sealed with a good exterior caulk.

3. A separate base flashing is required.

4. Flashing must be caulked to adjacent metal tiles.

1. May be reused if in serviceable condition and the proper type for a metal tile roof.

2. Plumbing pipes may be sealed to the flashing with flashing tape, rubber collar, or plastic cement.

3. Painting of flashing to blend with the roofing is desirable but not required.

4. Exposed galvanized nails in base flashing are acceptable.

5. A separate base flashing is required.

6. Flashing must be caulked to adjacent metal tiles.

1. Edge metal is required to cover batten structure and, if applicable, existing roof material.

2. Painting of edge metal is not required.

3. When flashing against a vertical side wall:

a. Install a 4” X 6” galvanized pan flashing.

b. Counter flash with wood or metal sealed to the wall with a good exterior caulk.

4. When flashing into a horizontal top wall, a weather block should be in stalled. On a high profile tile, the weather block should mold to the profile of the tile.

1. Ridge should be installed with one nail on each side into the supporting member.

2. Field tiles should be installed with 8d nails into the counter battens.

3. Spacing of ridge shingles shall match that of the field shingles unless other wise specified by manufacturer.

4. Rake tiles shall be fastened with two galvanized nails.

J. BUILDING DEPARTMENT INSPECTIONS:

1. Pre-inspection of roof overlays should be required.

2. In-progress inspections should include spot checks of decking, nailing, metal tile application, and flashing installation.

3. Final inspections should be done from the ground to prevent damage to the roofing material.