OATEY 11876 All-Flash® No-Calk® 3 in. – 4 in. Galvanized Black 12 in. x 15 in. Base Roof Flashing

The 11876 All-Flash No-Calk flashing takes 3 inch to 4 inch DWV pipe. The rubber collar slides down over the stack and seals against the pipe, so no caulking is needed at the penetration. If your vent stack is 1-1/2, 2 or 3 inch only, you need the smaller-collar version instead.

Good for pitch up to 40 degrees. The base is stamped to lay into the shingle courses and the collar slides over the DWV pipe, so anything from a low slope shingle roof up to a steep 40 degree deck is covered. Past 40 degrees you need a pitched or adjustable base flashing.

No. The 11876 is not for hot-mopped or built-up roofs. The hot asphalt and the solvents involved will attack the rubber collar, and the powder coated galvanized base is not made to be embedded in bitumen. For a built-up or modified bitumen roof use a flashing rated for hot-mop application. On an asphalt shingle roof it is the right part.

No sealant is needed at the pipe. That is what No-Calk means: the moulded rubber collar grips the DWV stack directly and makes the seal itself. Important on maintenance jobs, do not paint the collar and keep petroleum based products, roof cements and solvents off it, since those degrade the rubber. The collar is non-fading, so it will not chalk out to grey after a few seasons.

The base is stamped 29 gauge galvanized steel with a black powder coat over it, so it is rust-proof in service. The powder coat also keeps it visually flat against dark shingles instead of flashing bright metal at the penetration.

The base measures 12 x 15 inches. That matters for layout: you need enough exposed deck around the stack to lay the flange flat and lap the upper courses of shingles over the top edge, so plan the stack at least 8 inches or so down-slope from a valley or wall where the flange would have to bend.

Yes, it is approved for Type B installations as well as standard DWV plumbing vents, so the same part covers a 3 or 4 inch Type B gas vent penetration and a plumbing stack on the same roof. That is useful if you are standardizing one flashing across a building.

Order Oatey part number 11876. That is the All-Flash No-Calk, 3 inch to 4 inch collar, black powder coated 12 x 15 inch galvanized base. Oatey builds this same flashing in other collar sizes and base finishes, so the number is what pins down the black galvanized 3 to 4 inch version.

Each 11876 flashing weighs 1.15 lb, with a shipping volume of 0.313. Light enough to carry a handful up a ladder in one trip when you are re-flashing several stacks on a multi-family roof.