Expert: James Ball - 5/7/2011

Question
I have a Martin DV200A gas fireplace installed in 1992.  I have had problems with a marginal draft for yrs.  A service tech. looked at the vent termination.  The vent cap is actually siliconed to the storm collar & flashing.  There is a 9 pitch to the roof.  I have heard that a rule of thumb for gas chimney height is 3-4 inches for each inch of pitch.  My question is, is there pipe available to raise the venting a few feet.

Answer
Hello Les, all chimneys have ot follow the 3', 10' 2' rule, 3' above where you break the roof line., then go in a 10' circle, if you don't hit any thing you are good if  you do you keep going up till you clear the obstruction, then 2' above that. (minimum) check with your local building department.
If you can get the same pipe you can extend the chimney. I would have a local Certified Chimney Sweep www.csia.org, (there you can look up by zip code to find one near you) take a first hand look at what you have, they should be able to help.
Hope this helps
James