Firebrick: #1 Split P-0073

$ 11.12


As of February 1, 2021 we are no longer using UPS or USPS API shipping calculators for shipping brick into Canada due to the inconsistencies of shipping rates and the extreme increases in shipping cost. 

We recommend sourcing brick local if at all possible (see below).   If sourcing brick local is not possible contract martin@garn for a shipping quote. In your email indicate your shipping address and quantity of brick required.


Firebrick replacement (side) #1 splits:

Dimensions:  (4-1/2 in X 9 in X 1-1/4 in)

temperature rating of 2,850°F

Qty: 1

Firebrick Rating and Availability by Martin Lunde, PE

Each GARN® WHS unit has a combination of #1 and #2 splits. #1 splits (P-0073) are the thinner 4.5” x 9”x 1.25” brick that stand on edge along the sides of the combustion chamber. The #2 splits 9P-0074) are the thicker 4.5”x 9”x 2” brick that lie transversely on the bottom of the combustion chamber. Because of the high temperatures experienced in the combustion chamber only Hi-duty firebrick (rated to 2,700 F or higher) are recommended. All brick sold in the GARN store have been upgraded by our supplier to a maximum service temperature of 2,850 F. Standard “fireplace” brick does not have the Hi-duty rating, thus will not survive in a GARN WHS unit.

To date Hi-duty firebrick (2,850°F) were only available in the GARN store, However, #1 Hi-duty splits rated to 2,700 F have become available at big box retailer like  Home Depot, online only. Note the following:

    • The brick are sold by box (6 brick per box) and are less expensive than our brick due to their purchasing power. It appears orders over a specific dollar amount may ship free. Go online to get the specifics for your location (not sure if the Home Depot brick is available in Alaska or Canada). This is a very good deal for GARN WHS owners; however, we have not had any experience with this brick so cannot ascertain its quality or life.


#2 brick remain only available through the GARN Store.

The GARN store will continue to offer both #1 and #2 splits rated to 2,850 F. However, only #2 splits will be stocked. #1 splits will not be stocked, but will be available on a two week notice. In either case, shipping will be an added cost.

Firebrick breakage will occur as it is normal for brick to become more fragile with age and continued use. When significant breakage has occurred, it is necessary to replace the old firebrick and pads with new material.

Firebrick is available in numerous sizes and ratings. Some brick is “fired” (oven cured) and other brick is not. In order to achieve high efficiency and lower emissions, it is necessary to maintain high fire bed temperatures. Use only ASTM rated Hi-duty or better fired brick for replacement. Hi-duty brick has a minimum temperature rating of 2,850°F. Common or intermediate duty fire brick has a rating of 2,200 F. Never use unfired or patio type brick.
Two sizes of firebrick are used in the GARN® WHS,  #1 splits, each brick measuring 4 ½” x 9” x 1 ¼” thick. #2 splits, each brick measuring 4 ½” x 9” x 2” thick.
The thicker bricks (#2 splits) are positioned on the flat bottom of the chamber. The thinner (#1 splits) are positioned on both inclined sides of the chamber.  Three ¼” thick, flexible high temperature pads (Brick Pad P-0026)are placed between the steel combustion chamber and the firebrick.
Refer to the GARN Owners Manual.

For GARN model 1350 to 2500  units 1989 and newer 

9 – #2  (2” thick bottom brick Full Set) P-0074

18 -#1  (4 ½” x 9” x 1 ¼” thick side brick Full set )  P-0073  When replacing side brick only its recommend to replace the Side Brick Pad. Side Brick Pad part number P-0154.


When replacing both side brick and bottom brick its recommend to replace a full set of Brick Pad . Full set of Brick Pad part number P-0026.


For the newer 1000 H units with the water cooled air collar:

7 – #2  (2” thick bottom brick) P-0074

14 -#1  (4 ½” x 9” x 1 ¼” thick side brick)  P-0073

For the older 1000 H units with the air cooled collar:

8 – #2  (2” thick bottom brick) P-0074

16 -#1  (4 ½” x 9” x 1 ¼” thick side brick) P-0073

Additional information

Weight 4 lbs
Dimensions 9 × 4.5 × 1.25 in