asbestos insulated vent?

[kimball gray]

1950's house. Hot water tank has a b-vent attached to the exhaust hood on the tank. the b-vent goes up into the attic. Once in the attic, I see this pipe vent that looks like asbestos. What is it? There is another one on the gas heater vent in the attic space.

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[Scottpat]

1950's house. Hot water tank has a b-vent attached to the exhaust hood on the tank. the b-vent goes up into the attic. Once in the attic, I see this pipe vent that looks like asbestos. What is it? There is another one on the gas heater vent in the attic space.

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It is a transite flue pipe, aka cement asbestos pipe.

http://www.inspectapedia.com/sickhouse/ ... slookF.htm

[Bain]

We've discussed this before, Kimball. I think there were a couple of dissenting opinions, but you should know that most of us don't think Transite flue-pipes pose safety issues when they're located in attics and therefore we don't recommend replacement.

[kimball gray]

Thanks to your replies. This helps me out lots.

[waynesoper]

of course if your clients kids decide to go up there and chop it up and snort it you will be getting a call as to why you said it was OK. Asbestos is Asbestos no matter where it is and should be reported as such. Whether they can live with it, or not, should be up to them, not you!

[kimball gray]

Thanks, I did identify it but did not recommend that it be replaced.

[Neal Lewis]

How was the clearance at the roof sheathing? Many of these flues I've seen say 1 inch of clearance stamped on them.

[Chad Fabry]

I'd recommend it be replaced because it's too big for a water heater and Transite and gas ( I'm assuming it's not an oil fired water heater) fired appliances don't play well together. The gas fired exhaust gets cooled with dilution air and is well on its way to to a condensing temperature prior to entering the Transite flue. The Transite flue heats slowly and and the resulting acidic condensate erodes its interior.

Finally, I've never seen a gas appliance (excluding condensing units)that specified any material other than metal for a flue.

[Tom Raymond]

How was the clearance at the roof sheathing? Many of these flues I've seen say 1 inch of clearance stamped on them.

Most of the transite I see is fit so snug that it doesn't require any additional support.

Tom

[Scottpat]

Finally, I've never seen a gas appliance (excluding condensing units)that specified any material other than metal for a flue.

That is a very good point when dealing with home that has transite flue pipes.

[Bain]

I'd recommend it be replaced because it's too big for a water heater and Transite and gas ( I'm assuming it's not an oil fired water heater) fired appliances don't play well together. The gas fired exhaust gets cooled with dilution air and is well on its way to to a condensing temperature prior to entering the Transite flue. The Transite flue heats slowly and and the resulting acidic condensate erodes its interior.

Finally, I've never seen a gas appliance (excluding condensing units)that specified any material other than metal for a flue.

That last sentence . . . even if Transite would function properly, would a manufacturer really put in its instructions, "connection to an approved metal or Transite asbestos-containing flue pipe?" : )

[robert1966]

I saw a similar application on a hot water vent pipe in an older home in Galveston, TX. I listed it as a possible asbestos containing material.