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Masonry Fireplace
Clearance to Combustibles Test

UL-127 Protocol
OMNITEST Services, March, 2000

Measurement Locations
Data Sets

Lopez Labs Clearance to Combustibles Testing, MHA Annual Meeting, 2001
Lopez Labs Clearance to Combustibles Testing, MHA Annual Meeting, 2000
Lopez Labs Clearance to Combustibles Testing, Shawville, January 2000
See also Masonry Fireplace Clearance to Combustibles Testing at OMNITEST, May 2000
Draft Report - Fireplace Clearance to Combustible Testing at OMNITEST
by Jim Buckley
Building Code Clearances to Combustibles Debate


Efforts are under way to update the clearance to combustibles requirements for the ASTM Guide to Solid Fueled Masonry Heaters.

Jerry Frisch supplied the data below from the recent clearance to combustibles tests on a standard masonry fireplace, built to code, at OMNITEST Services.

This testing was funded principally by The Brick Industry Association (BIA) and Western States Clay Products Association (WSCPA). Additional funding and resources were provided by The Masonry Heater Association (MHA), Jerry Frisch, and Jim Buckley.

These results are preliminary.


The highest surface temperature reached on the masonry fireplace back was 239F, using a UL-127 fueling protocol (See description in OMNI draft protocol and comments, below).

ASTM E1602 currently specifies a maximum surface temperature of 230F for masonry heaters, with unspecified fueling.


Back of fireplace showing thermocouple locations and data
acquisition system.

On the side wall of the fireplace, there are surface thermocouples directly underneath the combustible plywood touching the wall (zero clearance).

Start of test, 9:35 am

Brands are added every 7.5 minutes for 12 hours. Stack of brands
visible to the right of the clock.

see also:
additional description and data in Jim Buckley's Report

Measurement Locations:

Mearsurement locations included 5 calibrated thermocouples located
at the rear of the fireplace back at 12" height increments, as shown below:

The same locations were used in recent Lopez Labs tests on an
unfaced masonry heater core.


Surface temperature data were taken by Jerry Frisch (Lopez Labs) with a
Raytek RT-2 infrared thermometer. Simultaneous data were taken by OMNI
with calibrated thermocouples, using an automated data aquisition system,
shown in the first photo, above.

The IR thermometer data is shown in the graph below. Temperatures are in
degrees Fahrenheit.

Data Sets:

Download the data in Excel 97 format. Check back regularly for updates


Proposed OMNI Test Protocol for Clearance Test on
Standard Masonry Fireplace

Feb 20/00 Comments by Norbert Senf

This page last updated on June 1, 2008

This page created on March 26, 2000
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