chimney pipe extension - Contractor Talk - Professional Construction and Remodeling Forum

trade · 03-31-2009, 09:55 PM

Now that progress has been made in repairing this, I've found a replacement cap that, after removing the existing cap and touting it around from any possible business that might have something to do with chimney cap knowledge(yeah this is a new one for me). What needs to be addressed now is what pipe to use for an extension, if figured correctly, I need 8" or more pipe to exceed the 36" distance from the highest structure within 10'(in this case the ridge) to fulfill local code. My question is: what type of pipe is needed, Type A, B ,single, double, triple wall, stainless or galvanized . Pardon the ignorance, but this is the first time coming across this.

I'll have more detailed photos to better explain this coming soon.
Thanks

trade · 03-31-2009, 11:38 PM

The dimensions were obviously obscured due to the damage. The recommended replacement was the Weathershield WSA-10TDW-ICP for a 10" flue, the outside dim. being 16". To go with a larger flue connection, an 11", it would mean the outside rim would be 19" instead of 16".
Any advice?

tom m · 04-01-2009, 08:55 AM

What are you doing? You shouldnt be screwing around with this. What caused this thing to melt? That outer ring looks like a heat shield not part of the flue. You cant just change sizes for things your unsure of. That flue is sized by furnace type, btu input distance and turns. Too much for a carpenter without that knowledge.

MechAcc · 04-02-2009, 06:47 AM

What is this vented to is the first question? Gas furnace, Oil furnace ? Second is this on a mobile home furnace? If so you will have to get the make and model number of the furnace. If the vent is damaged going into the roof to the furnace the roof jack should be replaced. You will have to measure from the top of the furnace to the roof line to get the correct height jack as they do come in various lengths. You'll need the manufacturer and furnace model number to get the correct vent jack. Coleman and Intertherm/Miller vent jacks look similar but they cannot be cross mixed as there are slight variations in the diameters and will allow recirculation of vent gases to be pulled back down the combustion air side of the vent jack and will cause pilot outages or recycling of the burner if it has auto ignition. If just need a new cap and extension pipe you'll still need the manufacturer and model number as extensions must be matched to the make of furnace.

Under no circumstances use standard galvanized pipe to make extensions on a manufactured/mobile home furnace as they will not fit properly and will allow recirculation of vent gases to the combustion air side of the vent.

trade · 04-02-2009, 09:59 AM

Considering all professional advice that was given both here and elsewhere, I informed the customer this job would be better left to someone who specializes in that trade, HVAC. She is a friend who I'm looking to do further business with.

tom m · 04-02-2009, 11:47 AM

Quote:

Originally Posted by trade

Considering all professional advice that was given both here and elsewhere, I informed the customer this job would be better left to someone who specializes in that trade, HVAC. She is a friend who I'm looking to do further business with.

Good call!

I have been selling work for years to the same people because they come to me for to look out for thier interests. If I can do it, I do, if I cant I get someone or refer them to someone. Its that kind honesty and trust that keeps them coming back.