The Flue Stretcher is designed to prevent downdrafts caused by rooflines and other nearby structures or from neighboring flues. Your chimney's draft capabilities highly depend on it's length and location in relation to other structures. If your chimney is lower than your roof line smoke can be forced back down your chimney. This can be caused by many things like large trees, garage roofs, additions etc. By adding onto the flue height you can usually cure the problem altogether.
The other common problem occurs when you have two adjacent flues leading to two different fireplaces on two different levels of your house. The negative pressure from the lower fireplace wants to draw the smoke from the upstairs fireplace down the flue when only the upstairs fireplace is being burned. By adding the flue stretcher to the upstairs flue you can create space between the two flues allowing the smoke from the upstairs flue to get away from the draw of the downstairs flue.
The Flue Stretcher is available in 1' and 2' heights. It attaches to your flue with screws on all four sides for extra security. The base is extra rigid to hold the screws tight to the flue. Load tests simulating side winds and updraft conditions of several hundred pounds of force demonstrate the Flue Stretchers mounting system holds tight. A stainless steel finish ensures a long life.