Specification No. 210-4 (4-ply)*
Nailable decks without insulation: Coal Tar Saturated Organic Felt

Aggregate Surface

Nailable decks: Plywood, wood plank, lightweight insulating concrete, poured and precast gypsum.

Slope requirements: 1/2" per foot (4%) maximum. See Slopes for possible slope restrictions or variations.
Materials per 100 sq. ft. (9.3m²) of roof area *Approximate Weights
Rosin Sheathing Paper
(Wood Decks Only.) 		1 ply 5 lbs. (2.3kg)
Coated Organic Base Sheet
(Non-perforated) 		1 ply 43 lbs. (19.5kg)
Tarred Organic Felt
(Mopped in Pitch) 		3 plies 45 lbs. (20.4kg)
Roofing Pitch (3 moppings @ not less than 20 lbs. (9.1kg) each) 60 lbs. (27.2kg)
Top Pour (not less than 70 lbs.) (31.8kg) 70 lbs. (31.8kg)
Surfacing: Gravel 400 lbs. (181kg)
*Actual weights used will vary depending on many job site factors; therefore, Koppers does not assume responsibility for actual weights applied.

Application of Membrane
  1. (Wood decks only.) Over the surface of the roof deck, install one layer of rosin sheathing paper weighing approximately 5 lbs. per 100 sq. ft. (2.3kg/9.3m2). Lap each sheet at least two (2) inches (51mm) and nail sufficiently to hold in place.
  2. Apply over entire surface, one (1) ply of Koppers non-perforated coated base sheet, lapping each sheet three (3) inches (76mm) over preceding sheet and nailing at lap on nine (9) inch (229mm) centers and stagger nailed down center of each sheet on nine (9) inch (229mm) centers.
  3. Over the entire surface, apply (3) plies of Koppers Tarred Felt, lapping plies twenty-four and two-thirds (24-2/3) inches (626mm), so that in no place shall felt touch felt.
  4. On short run slopes in excess of one-half (1/2) inch per foot (4%), such as on crickets and saddles, and when the deck permits nailing, nail along back of upper edge of each sheet six (6) inches (152mm) from the back edge on twenty-four (24) inch (610mm) centers. Where deck does not permit nailing, nailing strips are required and each sheet must be nailed along back of upper edge at spacings to assure penetration of nailers.
  5. For enveloping procedures, see section regarding Bitumen Control.
  6. Pour over the entire surface of the roofing membrane, a continuous coating of coal tar, and, while hot, apply not less than four hundred (400) pounds (181kg) of gravel or three hundred (300) pounds (136kg) of slag for each one hundred (100) square feet (9.3m2).
NOTE: Rosin paper, base sheet and reinforcing felts must be installed the same day.


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