allseason Posted February 12, 2013 Report Share Posted February 12, 2013 Does anyone have any info on the clearance of closed cell Spray Polyurethane Foam from a gas supplied metal flue pipe. I encountered some in a basement and it's about 1/2" away in spots, not to mention overspray on the flue itself. Thanks ahead of time. Quote Link to comment Share on other sites More sharing options...
Bill Kibbel Posted February 12, 2013 Report Share Posted February 12, 2013 Well, is the "flue pipe" a vent connector? A B-vent? Quote Link to comment Share on other sites More sharing options...
allseason Posted February 12, 2013 Author Report Share Posted February 12, 2013 Single wall vent connector for a water heater going into a masonry chimney. Quote Link to comment Share on other sites More sharing options...
Bill Kibbel Posted February 12, 2013 Report Share Posted February 12, 2013 Since polyurethane foam is not non-combustible, the single-wall connector clearance requirement is 6". Quote Link to comment Share on other sites More sharing options...
allseason Posted February 12, 2013 Author Report Share Posted February 12, 2013 Thanks Quote Link to comment Share on other sites More sharing options...
Marc Posted February 12, 2013 Report Share Posted February 12, 2013 Except that all expanding foam in residential is required to be fire retardant treated. Contact permitted, as far as I could determine a year ago when I last checked. A friend has it in contact with B-vent. Marc Quote Link to comment Share on other sites More sharing options...
Tom Raymond Posted February 13, 2013 Report Share Posted February 13, 2013 The fire retarder is so that the foam meets flame/smoke index to be left exposed, ie band joist applications, not to make it un-burnable. It most certainly would still be flammable in contact with a vent connector. Less so with the b-vent, that's why the clearance is only an inch. They're both wrong. Quote Link to comment Share on other sites More sharing options...
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