QUESTION 1 - I saw a new solid fuel-burning appliance for sale which didn't have a listing label, but the salesperson said the label wasn't needed and the product was approved for sale in Massachusetts. Does the Building Code approve individual, solid fuel-burning appliances without the label?

ANSWER 1 -While the Building Code itself does not approve individual products, it does require that all solid fuel-burning appliances which are to be installed in Massachusetts carry a permanently attached label on the appliance indicating that it has successfully passed certain National Standards Tests and otherwise conforms to the listing requirements. Therefore, if you are looking for a new appliance and it is not properly listed and labeled, do not buy it for use in Massachusetts.

QUESTION 2 - If I live in a "stand-alone" one- or two-family dwelling, can I install the solid fuel-burning appliance myself?

ANSWER 2 - A homeowner of a one- or two-family "stand-alone" dwelling is allowed to perform building permittable work without having a Construction Supervisors License (see also 780 CMR, Section 108.3.5) however the homeowner is required to obtain a building permit for such installation, and otherwise comply with all applicable requirements of the Building Code and of the manufacturer.

QUESTION 3 - If I am the owner of an existing one- to four family, owner-occupied residential building and I want to hire someone to install a solid fuel-burning appliance; does that individual or company need to have a Home Improvement Contractor Registration (HICR)?

ANSWER 3 - Depending on how the contract is structured, most likely YES. If the total Contract cost is $500.00 or greater, then yes, the person with whom you contract for such services is required to be Registered with the Office of Consumer Affairs as a Home Improvement Contractor in accordance with the requirements of MGL c.142A and 780 CMR R6.

Additionally, if the Contract cost is $1000.00 or greater, then the contract must be in writing and comply with the requirements of MGL c.142A and 780 CMR R6.

QUESTION 4 - Is the contractor who is installing a solid fuel-burning appliance required to be licensed as a Construction Supervisor?

ANSWER 4 - Yes, unless the homeowner is entitled to the Construction Supervisor License Exception as set forth in 780 CMR 108.3.5 (see Question 2 /Answer 2 above).

QUESTION 5 - My central heating appliance is connected to my chimney flue, can I also connect a solid fuel-burning appliance to this flue?

ANSWER 5 - No. The Building Code prohibits such connections.

QUESTION 6 - I have an older solid fuel-burning appliance which was manufactured prior to the 1982 labeling requirements and is already installed. Can I use this appliance even though it has no label?

ANSWER 6 - The Building Code allows for the use of a non-conforming, non-labeled appliance if it is already installed, however it is important that you refer to the Building Code, (780 CMR 60) for further guidance as well as your local building inspector when working with an older, non-labeled appliance.

QUESTION 7 - If I can't get the exact fuel that my solid fuel-burning appliance requires, can I substitute a different fuel in that solid fuel-burning appliance?

ANSWER 7 - No, A solid fuel-burning appliance must be operated with the intended fuel for which it is listed to ensure safe operation.

QUESTION 8 - My solid fuel-burning appliance Installation/User's Manual states that the hearth extension floor protection must meet a minimum thermal conductivity ("k") or maximum thermal resistance ("R") and that the hearth extension must also be of non-combustible finish. Can I use substitute a non-combustible hearth rug for the hearth extension?

ANSWER 8 - Probably not. Although the hearth rug is non-combustible, it may not have the necessary low thermal conductivity ("k") or high thermal resistance ("R") to slow the release of heat energy into the combustible floor system that the hearth rug is covering. Even if you install non-combustible decorative ceramic tile over insulating board or heavy plywood, this is usually insufficient to provide a sufficiently low thermal conductivity (or sufficiently high thermal resistance) for appliances. (refer to Appendix 120W of 780 CMR for guidance on determining the thermal conductivity "k").

QUESTION 9 - I am installing a "zero clearance" factory-built fireplace which has a number of metal standoffs or tabs on the outside which make contact with the rough wood framing. Can I remove or bend these tabs to make it easier to install the factory built fireplace into the rough frame structure?

ANSWER 9 - NO! The standoffs or tabs are specifically designed to keep the hot portions of the factory-built fireplace away from combustible construction. The term "zero clearance" is somewhat misleading and means that the extremely hot portions of the steel factory-built fireplace must never contact combustible structure. The installation instructions for factory-built fireplaces will contain clear guidance on clearances to combustibles, including clearances to combustible structure and combustible decorative trim.

QUESTION 10 - What is "k" or "R" that I see in the Manufacturer's installation instructions?

ANSWER 10 --Thermal conductivity, identified as "k" is the amount of heat (in Btus) that will flow in one hour through one square foot of a uniform material one inch thick for each degree ( 0F) of temperature difference from one side of the material to the other - the larger the "k" value, the more heat energy that can be conducted through the material and the lower the "k" value, the less heat that can be conducted through such material.

The measurement "k" of thermal conductivity is directly applicable to a single material but when more than one material is joined to form a composite material (i.e., ceramic tile over "cement board"), it is necessary to first convert from "k" to "R" ("R" is the "thermal resistance" and "R" values for different materials in a composite can be added whereas "k" values cannot be directly added when dealing with composite floor protection materials).

To convert "k" to "R": "R" = actual inches of thickness of the material ÷ "k"

To convert "R" to "k": "k" = actual inches of thickness of the material ÷ "R"

A low value of "k" or a high value of "R" ensures less heat energy is being conducted through the floor protection/hearth extension system.

A high value of "k" or a low value of "R" ensures a greater amount of heat energy is being conducted through the floor protection/hearth extension system.

If the appliance Manufacturer calls for a specific non-combustible material and a thickness, then it is a simple matter to install the correct thickness of the specified material and no calculations are required. If this is done then any overlaying, non-combustible decorative materials (tile, brick, etc.) do not have to be accounted for relative to their thermal properties for fire protection.

If the appliance Manufacturer, specifies a "k" or "R" value of the "hearth/hearth extension/floor protection then the materials that will be used need to be installed in sufficient thickness to meet the Manufacturer's specification. In order to determine the material thickness the "k" or "R" values of the each material is required. The following link will bring you to sample calculations .

QUESTION 11 - Can you list the key items that I must consider for installing and using a solid fuel burning appliance?

ANSWER11 - A checklist is found in the table below:


Solid Fuel Burning Appliance is Listed and Labeled, boilers are stamped with the A.S.M.E code symbol stamp.


Installer holds a Construction Supervisor License (CSL) (unless the homeowner is going to install the appliance).


If installation is an owner-occupied building of up to 4 units, the individual signing the contract with the homeowner holds a Home Improvement Contractor Registration.


The Building Permit is obtained prior to installation.


The location where the appliance is being installed has a satisfactory supply of fresh air.


The location where the appliance is being installed is NOT near flammable vapors, gasoline, explosives or other combustible liquids, fibers or dust.


The location where the appliance is being installed provides for the required clearances from combustible construction and other objects such as furniture, drapes, carpets, etc., etc.


The location where the appliance is being installed has proper floor protection/hearth extension under or in front of the appliance.


The appliance has proper venting to the outside of the building.


If the appliance vents through a chimney, the connector pipe from the appliance to the chimney is the correct type and size and is installed with the required clearances to combustibles.


If the appliance vents through combustible walls or roof or ceiling, the vent system uses listed thimbles or specialized piping or free clearances where the vent system passes through combustible construction.


The appliance does not share a flue or vent with other appliances.


The building inspector has inspected the appliance after installation but before use.

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