This M-Flex Chimney liner has the greatest acid fighting capability! Our unique manufacturing system used to make M-Flex, utilizes a continuous strip of stainless steel, interlocked and diagonally crimped to produce a gas and watertight seam of superior strength & durability. Its corrugated construction allows for expansion and contraction during the heat up and cool […]

2-Ply 3003 aluminum liner can be used to vent Category I gas appliances with A.F.U.E. of 83% or lower. In many cases, especially when only water heaters are vented into masonry flues, the gas appliances are vented into oversized flues. This practice may cause serious condensation and performance problems. By relining the chimney with National […]

M-FLEX liner is made from 316L stainless steel and is designed to reline existing chimneys or to be used in new construction. National Chimney manufactures M-FLEX liner from the highest grade mill certified stainless steel alloy. It is made from a continuous strip of 7-ply stainless steel that is interlocked and crimped to produce a […]