Buckley Rumford Fireplaces
BOCA and Open Fireplaces
1989 BOCA code changes
by Jim Buckley
When I changed the BOCA Code in 1989 to permit Rumford fireplaces as shallow as 12" deep, by adding Section 2402.1.1, I also added Section 2402.7 (below) and Section 2402.2.2 about smoke chamber wall thickness to allow me to continue rebuilding existing Victorian coal and gas-burning fireplaces. Typically the chimneys in these homes have an 8"x 8" unlined flue and I need an 8" liner to work with my Rumford fireplace conversions. I ran a lot of rigid 8" diameter stainless steel flue liner.
There would be a good market if we could change the code which currently does not allow relining except that which meets UL 1777 - and that rules out 8" liners necessary for most of the fireplaces.
Relining language in the 1990 BOCA Code:
2402.7 Existing masonry chimneys: Existing masonry chimneys are permitted to be used to vent open fireplaces only - even if the existing chimneys lack the clearances to combustibles as required by M-1205.4 of the mechanical code listed in Appendix A - provided that such chimneys otherwise conform to the requirements of Article 12 of the mechanical code listed in Appendix A or can be made to conform to such requirements through repair or relining.
The 2006 IRC re-states this recognition that open fireplaces are safer, have cooler flue-gas temperatures and are less likely to have chimney fires in that the code allows the less rigorous UL103 standard for open fireplaces whereas all other solid-fuel appliances must be vented by chimneys that meet the UL103HT (high temperature) standard.
R1005.3 Solid-fuel appliances. Factory-built chimneys
installed in dwelling units with solid-fuel-burning appliances
shall comply with the Type HT requirements of UL 103 and
shall be marked "Type HT" and "Residential Type and Building
Heating Appliance Chimney."
The NFPA 211 code has long recognized that open fireplaces are safer than closed combustion chamber appliances and allowed factory-built chimneys to meet the less stringent the UL 103 (not the HT) standard. See NFPA 211 on Reduced Standards for Chimneys Venting Open Fireplaces Now that language has been added to the IMC as well. See IMC on factory-built chimneys. And in 2006 it's in the IBC and IRC.
Exception: Chimneys for use with open combustion chamber
fireplaces shall comply with the requirements of UL103
Maybe it's time again to make the case to permit existing masonry chimneys that are in contact with combustibles be used to vent open fireplaces as log as they otherwise meet code.
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Buckley Rumford Fireplaces
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