Mason-Lite 33" Standard Wood Burning or Gas Firebox Kit - MFP33
The Mason-Lite 33" Standard Wood Burning or Gas Firebox Kit (MFP33) is a premium, factory-engineered masonry firebox designed to deliver the authentic look and performance of traditional brick fireplaces with modern efficiency and easier installation. Built for both wood-burning and gas log applications, this 33-inch firebox system offers exceptional durability, versatility, and code-compliant safety for residential and multi-story installations.
Engineered as a lightweight masonry system, the MFP33 reduces structural load while maintaining the strength and thermal performance of conventional site-built fireplaces. It is UL127 tested and designed for use with UL103 Class A chimney systems, ensuring safe venting and long-lasting operation. Ideal for new construction or remodeling projects, this firebox supports a wide range of finishing options, including brick veneer and custom firebrick linings for a high-end architectural fireplace look.
With its proven masonry construction, superior heat resistance, and flexible fuel compatibility, the Mason-Lite MFP33 is a trusted choice for homeowners, builders, and architects seeking a reliable, high-performance fireplace solution.
Features
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Dual Fuel Compatibility – Designed for use with both wood-burning fires and approved gas log sets
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33-Inch Firebox Opening – Compact size ideal for standard residential fireplace designs
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Lightweight Masonry Construction – Up to 50% lighter than traditional site-built masonry fireplaces
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UL127 Listed Safety Design – Tested for safe operation with proper chimney systems
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UL103 Chimney Compatible – Works with Class A chimney systems for efficient venting
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High Thermal Performance – Engineered for excellent heat retention and durability
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Multi-Story Approved Installation – Suitable for multi-level residential builds
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Combustible Floor Approved (with system components) – Flexible installation options
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Custom Finish Options – Compatible with brick veneer and firebrick liners
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Made in the USA – Manufactured with quality domestic materials
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Professional-Grade Build – Designed for contractors, builders, and fireplace installers
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Optional Accessories Available – Includes gas kits, outside air kits, and framing components
Specifications
| Specification |
Details |
| Model |
MFP33 |
| Brand |
Mason-Lite |
| Firebox Opening (W x H x D) |
30" x 22.5" x 21.5" |
| Overall Unit Height |
54.5" |
| Footprint Dimensions |
37" x 28" |
| Framing Dimensions |
41" W x 30" D x 56.25" H |
| Flue Diameter |
12" (Class A UL103 chimney required) |
| Fuel Type |
Wood-burning or approved gas log set |
| Certification |
UL127 Listed (Factory-built masonry fireplace) |
| Clearance to Combustibles |
2" (sides & back) |
| Installation Types |
Flush, corner, internal wall, full projection |
| Fireplace Weight |
Approx. 1,091 lbs |
| Mortar & Rebar Weight |
Approx. 60 lbs |
| Ready-Mix Requirement |
Approx. 150 lbs |
| Chimney Compatibility |
UL103 Class A metal chimney system |
| Floor Compatibility |
Suitable for combustible and non-combustible floor systems |
| Heat Rating |
Tested up to approx. 1700°F |
| Construction Type |
Precast lightweight masonry system |
| Origin |
Made in USA |
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