12. Installation – a technique for sealing a fluepipe into an existing chimney. A useful technique for connecting a metal fluepipe into a masonry chimney is shown at right. XXBefore commencing, clean the bottom chimney liner thoroughly with a wire brush and abrade it lightly with an angle-grinder to key the surface. XXNext, wrap a thick bandage of rockwool (A.) around a 300mm (12") section of pipe and try fitting the pipe into the base of the chimney. Adjust the amount of rockwool you use by trial and error until the pipe is wedged in place absolutely securely. XXNow mix some cement and Micafil together in a ratio of 1:6. Take a fistful of the mix, push it up through the pipe and drop it over the edge so that it lands on the rockwool. Continue until the gap between the fluepipe and the chimney liner has been filled with the mixture (B.) XXThroughout this exercise the purpose of the rockwool is to hold the pipe securely in place while acting as a support for the cement/Micafil mix. Leave the mix for a day or two to cure fully, then load your fist with fire-cement and flaunch or 'feather' the top of the fluepipe into the chimney with your fingertips so that any moisture trickling down is directed into the inside of the fluepipe. XXThis technique can eliminate the need to break into the chimney breast, but may not be feasible if the difference in diameter between the chimney and fluepipe is excessive.