Asbestos Vent Pipe???

Is this a cement asbestos vent pipe? Surface and feel was just like a cement asbestos siding shingle. First time see one of these. Asbestos siding is very common around here and other than general statements & disclaimers about painting, scraping, chipping, disposal, etc. replacement is not recommended. Should replacement be recommended on this vent pipe? If so how should it be disposed of?

Single wall vent pipes are not allowed in attics… hmmmm

Looks like transite material to me, could contain asbestos.

I do not make reccomendations on how to handle known asbestos materials.

I do not test for asbestos.

If the client is concerned they could have it tested and and removed according to the local/state standards.


Asbestos is only hazardous when airborne. If the pipe is otherwise OK, I wouldn’t recommend replacement.

Single wall vent pipe needs 6" to combustible material clearance.:slight_smile:

If it looks like asbestos it probably is abestos particularly if the home was built pre 70’s. But without labratory analyze that is not 100 percent certain. But age of the material is a good onsite clue.

As long as the pipe is in good condtion, (ie. not torn, lose, or damaged, it could be left in placed. It looks like the section of the flue could be cut out without much effort and damage and the section replaced. Of course other precautions should be provided while removing the item.

It looks like there is a metal collar around the pipe, which would be consistent with the time period when they used single-wall vents in this type of application. While I don’t summarily recommend replacing flues that could contain asbestos, I do recommend upgrading to a Type B flue for this application. We had a fire here in San Diego last summer that they blamed on the single-wall vent for the water heater. Unfortunately, the lack of a recommendation to have the flue upgraded also landed the home inspector in court. I believe they settled out of court with the home inspector’s insurance company paying for $100,000 worth of damage.

Damed if you do Damed if ya don’t…

I agree with everyones post so far…
Was the flue encapsulated in high temp paint or is the picture that weak to my eyes… Dang I wish we could post bigger better pics…:frowning:

It looks as if there is a thimble in the ceiling but the interesting part is most of the ones around here are less 1-1/2 inch spacing from the surface of the flue side.

Like Brian stated: Single wall vent pipe needs 6" to combustible material clearance.:smile:

I don’t see that with old thimbles around here. Old standards…

Burn’in down the house…:wink:

I believe the 6" clearance requirement applies to single wall METAL vent.
The materials in transite pipe perform the same function as the air space in double wall metal vent pipe.

Try this test. Aim your laser thermometer at a single wall section of vent with a gas appliance running. Then do the same with double wall and transite. The transite will be even cooler than the double wall.
Asbestos is a great insulator, it just happens to be hazardous
when inhaled!

I believe the 6" clearance requirement applies to single wall METAL vent.

Asbestos is a great insulator, it just happens to be hazardous when inhaled!

Code reference perhaps?:cool:

The IRC states the 6" clearance is for single wall metal pipe. Obviously, there will not be a reference to transite, since it hasn’t been made for a year or two. :stuck_out_tongue:

Two of the old timers I’ve talked to said they remember the clearance for transite was one inch to combustibles. Doesn’t sound like it’s the same as metal pipe to me!

Nice Joseph, but where in the code does it mention transite vent pipe?

Read my last post. Transite will not be mentioned in modern day codes because it has not been installed for decades. That doesn’t diminish it’s ability to function, however. All I was saying is that when codes reference single wall pipe, they are referring to metal, not any other material.

Transite insulates BETTER than metal “B” vent, so I don’t see where the 6" clearance rule would apply (since it is NOT single wall metal).

I would write up transite clearance of less than two inches, just because that is the required clearance for double wall. But from talking to some older installers around here, they remember the code (at that time) being 1" clearance to combustibles. If I ever find an old code reference stating that, you’ll be the first to know. :cool:

You are correct Joeseph, transite vent piping is not recognized by current code/standards.

Now if you wish to do inspections to outdated standards, by all means have at it.:cool: Seem tricky to me.:slight_smile:

Run a gas appliance with single wall METAL vent and touch the pipe. IT’S HOT. 6" clearance required to combustibles.

Run a gas appliance with “B” vent and touch the pipe. IT’S WARM. 2"
clearance required to combustibles.

Run a gas appliance with transite vent installed. IT’S COOL. (Cooler than the “B” vent would be) 6" clearance required? Why??

If you want a 6" clearance for transite pipe to combustibles that’s your call. After growing up in my father’s heating and A/C business, and talking to guys that have been installing since the 40’s and 50’s, I’m letting common sense prevail.
If you want to treat transite and single wall metal as the same, have at it.

I believe it’s 1". :wink:

Actually, in a certain demented sort of way, Transite is recognized by current code/standards, for current code/standards state that generally, an older building does not need to be brought up to current code/standards except in specific circumstances and conditions.

I believe the code is quite clear about following manufactures installation guidelines. I am having trouble locating any that call out Transite Flue Pipe.

Transite is covered under asbestos since Johns Manville has definitively stated that Transite does, indeed, contain asbestos.