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Most recent proposed wording, by Chip Clark (April 7/00)(20 Kb Word for Windows document)
Report by Norbert Senf
also, see Report by Walter Moberg
A meeting was held in Washington, D.C. on Oct 15/99 to sort out a dispute between a group of 3 manufacturers (Hearth Products Association Masonry Heater Manufacturers' Caucus) and The Masonry Heater Association (MHA). At issue is the wording of the masonry heater section in the new International Building Code (IBC) and the new International Residential Code (IRC).
The meeting was useful in getting the parties to move closer to a united position. A continued internal industry conflict will hinder progress with the Building Code organisation.
The main point of remaining disagreement is on the critical issue of masonry heater clearances to combustibles. In addition to the existing prescriptive language, the manufacturers are demanding an escape clause that would give them Carte Blanche in setting clearances:
"or distances specified according to the manufacturer's instructions"
Members of the MHA Executive oppose this, on the grounds that it does not adequately insure public safety. Anyone who prefabricates a masonry heater is a manufacturer. Under the proposed clause, they would not have to follow any peer-reviewed standards in setting clearances to combustibles to assure fire safety.
It is hoped that a resolution can be found for this issue before the Nov. 1 deadline for submitting change proposals for the next code cycle. MHA suggested that it submit the agreed-to modifications to IBC, and that the manufacturers submit the same language, with the addition of the disputed clause. The manufacturers, however, threatened to submit a request for disallowal of the existing IBC language unless MHA agreed to the disputed clause.
Clearly, the request for disallowal would not be in anyone's interest. Efforts are under way to find an interim solution. The manufacturers were recently successful in getting MHA-proposed language defeated in the new International Residential Code (IRC). They did not succeed in a similar effort with the IBC, however, and we now have building code language specifically addressing masonry heaters.
IBC is the first Model Building Code in North America to contain masonry heater language. Masonry heaters are also addressed in the new Minnesota Ventilation Code and the Canadian R-2000 Standard. In addition, several American states now recognise masonry heaters in local clean air regulations.
topNorbert Senf, Oct 22, 1999 (Reply to Walter Moberg's Oct. 21 comments)
Jim Buckley
-Report on Masonry Alliance on Codes and Standards Meeting, March 9-10/00
topSECTION R1005
MASONRY HEATERS
R1005.1 Definition. A masonry heater is a heating appliance constructed of concrete or solid masonry, hereinafter referred to as masonry, having a mass of at least 800 kg (1760 lbs.), excluding the chimney and foundation, which is designed to absorb and store heat from a solid fuel fire built in the firebox by routing the exhaust gases through internal heat exchange channels in which the flow path downstream of the firebox includes at least one 180 degree change in flow direction before entering the chimney and which delivers heat by radiation from the masonry surface of the heater which shall not exceed 230 degrees F (110 degrees C) except within 8 inches (203 mm) surrounding the fuel loading door(s).
R1005.2 Installation. Masonry Heaters shall be listed or installed in accordance to ASTM E-1602
R1005.3 Seismic reinforcing. Seismic reinforcing shall not be required within the body of a masonry heater whose height is equal to or less than 2.5 times it's body width and where the masonry chimney serving the heater is not supported by the body of the heater. Where the masonry chimney shares a comon wall with the facing of the masonry heater, the chimney portion of the structure shall be reinforced in accordance with Section R1006.
R1005.4 Masonry heater clearance. Wood or other combustible framing shall not be placed within 4 inches (102 mm) of the outside surface of a masonry heater, provided the wall thickness of the firebox is not less than 8 inches (203 mm) and the wall thickness of the heat exchange channels is not less than 5 inches (127 mm). A clearance of at least 8 inches (203 mm) shall be provided between the gas tight capping slab of the heater and a combustible ceiling. The required space between the heater and combustible material shall be fully vented to permit the free flow of air around all heater surfaces.
topMike Van Buren, HPA's Technical Director, has written up and forward the agreed
upon and the disputed language, below.
Briefly, the main changes are:
top top1. Definition A Masonry Heater is a heating appliance constructed
of
concrete or solid masonry having a mass of at least 500 kg (1,100 lb.),
excluding the chimney and foundation which delivers heat by radiation
from the masonry surface of the heater.
It is designed to absorb and store a substantial portion of heat from a
solid fuel fire built in the firebox by routing exhaust gases through
internal heat exchange channels in which the flow path downstream of the
firebox includes at least one 180 degree change in flow direction before
entering the chimney.
2. Installation A Masonry Heater shall be installed according
to one
of the following:
1. The terms of its listing.
2. ASTM E 1602 and the manufacturer’s instructions
3. ASTM E 1602 and under the supervision of a skilled masonry heater
builder
3. Seismic Reinforcing Masonry heaters shall be anchored
and
reinforced as required in this chapter. In seismic Design Categories A,
B or C, reinforcement and seismic anchorage is not required. In seismic
Design Categories D, E and F, masonry heaters shall be anchored to the
foundation. Seismic reinforcing shall not be required within the body
of a masonry heater whose height is equal to or less than 3.5
times its
body width (and ratio for width to depth of 3 to 2), and where
the
masonry chimney serving the heater is not supported by the body of the
heater. Where the masonry chimney shares a common wall with the facing
of the masonry heater, the chimney portion of the structure shall be
reinforced in accordance with Section 2113.
4. Masonry Heater Clearance Any portion of a masonry heater
shall
have a minimum air space to combustibles of either:
1. 4 inches (102mm) provided that the wall thickness of the firebox is
not less than 8 inches (203mm) of solid masonry, of which at least 4
inches includes firebrick conforming to ASTM C27 or ASTM C1261, laid
with refractory mortar conforming to ASTM C199 or
2. distances specified according to the terms of its listing, or
3. distances specified according to the manufacturer’s instructions.
Unless otherwise stated by the terms of the listing or the
manufacturer’s instructions, clearances to combustible shall be 4”,
and
the required airspace between the heater and the combustibles shall not
be filled, except to provide firestopping and fireblocking according to
Section R1003.14. A clearance of at least 8 inches (203mm) shall be
provided between the gas tight capping slab of the heater and a
combustible ceiling.
Revised wording proposal submitted by Walter Moberg, October 21, 1999 (12 Kb. PDF file)
Revised wording proposal submitted by Chip Clark, BIA, October 25, 1999 (10 Kb. PDF file)
topCurrent version of ASTM E-1602 with proposed revisions (450 Kb .PDF file)
MHA Seismic Analysis of Masonry Heaters, with Reinforcing Guidelines (1 Mb PDF file)
Defining Masonry Heaters - A Discussion Paper (57 Kb. PDF file)
MHA Position paper (no color graphics, 59 Kb PDF file)
http://mha-net.org/docs/position.PDF (with color graphics, 750 Kb PDF file)
Draft language for IRC (located at www.Rumford.com)
This page last updated
April 7, 2003
This page created on October 19, 1999