Type B Gas Vent requires a minimum of one-inch clearance to combustibles. Durability is the result of high-quality materials and workmanship, with galvanized outer pipe and aluminum inner pipe providing protection against corrosion and external damage. 3. Transite generally requires 1 to 3 inches depending on various factors. Thread starter Inspector 102; Start date Sep 12, 2013; I. Each type of vent pipe has recommended clearances to combustible materials. 2. Clearance is the distance that is considered to be safe between a heat-producing appliance, chimney, chimney liner, vent pipe, vent connector or other hot surfaces, and combustible materials. 1. With special factory supplied parts, 4" WV oval pipe can be installed at less than one inch clearance to combustible surfaces as a Type B-W vent for recessed wall furnaces or as a Type “B” vent through 2 x 4 walls. B-vent appliances are relatively efficient. Furnace vent pipe too close to combustibles. Add To List Click to add item Amerivent® 3" B-Vent Water Flex Vent Connector to your list. This one-inch is a typical clearance for all brands of Type B Vent, but each section of vent pipe is marked with the clearance required by Underwriter Laboratories, so it should be checked. Re: B vent clearance An insulation shield of no less than 26 gauge sheet metal shall be installed to to provide clearance between the vent and the insulation and extend no less than two inches above the insulation layer in the attic (IRC 2425.4). What are the Allowable Clearances? Clearances 1″ clearance to combustibles in single and multi-family dwellings. Metal Double wall / “B” vent requires 1 inch minimum clearance. Trim back the wood, shift the vent or …. Joined Oct 22, 2009 Messages 324 Location N/E Indiana. Sidewall B-vent termination. quick, strong vent action and eliminates condensation in the pipe or overheating of nearby enclosure surfaces. Refer to the owner's manual for complete clearance requirements and specifications. Below are the allowable clearances for a number of common situations. Metal single wall generally requires 6 inches of clearance. Actual product appearance, including flame may differ from image shown. Cons: B-vent must be installed through the interior of the home and terminate above the roof which may pose extensive installation labor costs or difficulties depending on the home. WHERE THE REQUIRED CLEARANCE WITHOUT PROTECTION FROM APPLIANCE, VENT CONNECTOR, OR SINGLE WALL METAL PIPE IS: 36 inches: 18 inches: 12 inches: 9 inches: 6 inches: Allowable clearances with specified protection (Inches) b: Use column 1 for clearances above an … Round Type B Gas Vent 18″ – 3″: aluminum .020″ inner wall, galvanized .021″ outer wall. The flame and ember appearance may vary based on the type of fuel burned and the venting configuration used. April 19, 2013. The problem with this is that the single wall pipe requires even greater clearances (6″). Heat output will vary depending on the type of fuel used. Compare Click to add item "Amerivent® 3" B-Vent Water Flex Vent Connector" to the compare list. Sku # 6373977. B-vent pipe itself is relatively inexpensive and simple to install. Click to add item "Amerivent® 3" B-Vent Water Flex Vent Connector" to the compare list. Type B Gas Vent is designed for negative pressure applications and flue gas temperatures not exceeding 400°F above ambient for Category I appliances. Inspector 102 Silver Member. 3″-16″ diameters feature twist-lock fittings, screws required for 14″ and larger diameters. Diameters 3″- 30″ … A proper vent with insulation baffle looks more like this: Insulation baffle around a B-Vent pipe in an attic