Single wall exhaust pipe

[nrichards]

Inspected a 50 yr old house with a gas water heater that was replaced in 1988. Still had the original single wall exhaust pipe, would the B-vent pipe have been the standard in 1988?

[Jeffrey R. Pope]

If it ran through the attic, or there are clearance issues, it should be a B-vent, even in 1988.

Single-wall vents are perfectly acceptable under the appropriate circumstances.

[nrichards]

Thank you. This pipe was in unconditioned space. It was double walled at penetration thru ceiling.

[Brian E. Kelly]

Originally Posted by nrichards

Inspected a 50 yr old house with a gas water heater that was replaced in 1988. Still had the original single wall exhaust pipe, would the B-vent pipe have been the standard in 1988?

Single wall metal pipe, or single wall transite pipe?