The Flue Stretcher raises the effective height of the flue solving two problems:
1.Reduces negative house pressures. Negative house pressures can pull the smoke from one flue down another right beside it. Adding the Flue Stretcher to the upstairs flue distances its smoke from the downward pull of the downstairs flue.
2. Increases Draft. By putting the flue opening above the roofs and other nearby structures you improve draft and reduce downdrafts.
Flue stretchers come in stainless steel or copper, and your choice of 1' and 2' heights. Mesh is 3/4inch on all sizes. Lifetime Warranty.