Skip to product information
1 of 5


Mason-Lite 39" Pre-Cast Masonry Firebox Kit for 12" Class A UL103 Chimney with Height Kit

Mason-Lite 39" Pre-Cast Masonry Firebox Kit for 12" Class A UL103 Chimney with Height Kit

Regular price $4,013.00
Regular price Sale price $4,013.00
Sale Sold out

Brick Panels

Red Split Herringbone Brick Panels for 39 in. Fireplace
Standard Buff Split Herringbone Brick Panels for 39 in. Fireplace
Red Full Running Bond Brick Panels for 39 in. Fireplace
Standard Buff Full Running Bond Brick Panels for 39 in. Fireplace
Red Split Running Bond Brick Panels for 39 in. Fireplace
Standard Buff Split Running Bond Brick Panels for 39 in. Fireplace

Metal Base

-- Please Select --

6 in. Structural Metal Base for 39 in. Firebox

No, Thank You

Air Kit

-- Please Select --

4 in. Combustion Air Kit -3' Flexible Vent and Plastic Hood

No, Thank You

Masonry Arch

-- Please Select --

No, Thank You

Height Kit

-- Please Select --

Mason-Lite Height Kits - Height Kit Includes (1) MFP39-2 & (2) MFP39-3

No, Thank You

Damper Kit

-- Please Select --

30 in. Cast Damper - for MFP39 (DAMPER BLOCK - MFP39 Included)

Damper Block for MFP39

No, Thank You

Burner Set

-- Please Select --

Natural Gas PureBurn Grate/Burner Set for MFP33 and MFP39

Propane Pureburn Grate/Burner Set for MFP33 and MFP39

No, Thank You


-- Please Select --

No, Thank You

Chimney Shrouds

-- Please Select --

32 in. Natural Copper Arlington Chimney Shrouds

32 in. Matte Black Arlington Chimney Shrouds

32 in. Dark Bronze Arlington Chimney Shrouds

32 in. Storm Gray Arlington Chimney Shrouds

36 in. Natural Copper Dover Chimney Shrouds

36 in. Matte Black Dover Chimney Shrouds

36 in. Dark Bronze Dover Chimney Shrouds

36 in. Storm Gray Dover Chimney Shrouds

40 in. Natural Copper Sussex Chimney Shrouds

40 in. Matte Black Sussex Chimney Shrouds

40 in. Dark Bronze Sussex Chimney Shrouds

40 in. Storm Gray Sussex Chimney Shrouds

40 in. Natural Copper Charleston Chimney Shrouds

40 in. Matte Black Charleston Chimney Shrouds

40 in. Dark Bronze Charleston Chimney Shrouds

40 in. Storm Gray Charleston Chimney Shrouds

No, Thank You

  • Free Shipping on Orders Over $300
  • Same-Day Order Processing
  • Easy Monthly Installments Starting at 0% APR*
Got a question?
• Text or call 888-992-1556
• Email
• Start a live chat

Our team is available to serve you 8:00 AM - 11:59 PM ET, 7 days a week.


Have you ever dreamed of the radiant warmth of a masonry fireplace in your bedroom? Or, do you dream of an outdoor fireplace where you can gather together with friends and loved ones? Dreams can come true with Mason-Lite masonry fireplaces. Our factory-built masonry fireboxes are affordable, easy to handle, and consistent in quality. A masonry fireplace adds luxury and increases the value of your home.

Recreating the tradition of the hearth and the elegance & romance of the flame, Mason-Lite captures the essence of the fireplace masonry artists have been crafting for centuries. And, with a proven history of superior quality, lightweight fireplaces for indoor and outdoor projects, it’s no wonder Mason-Lite is one of the industry leaders of modular concrete fireplaces.

At Mason-Lite, we use the finest aggregate materials available to build our lightweight modular concrete fireplaces. One of the main ingredients is pumice, a natural-fired volcanic rock with tremendous strength.

Its lightweight attributes are second to none, and because of its pre-fired beginnings, pumice retains heat better than any natural aggregate available. The best sources for USA pumice are in the western states, convenient to Mason-Lite’s California-based production facilities. Pumice is formed when gas-rich, frothy magma rapidly cools, creating air pockets that contribute to its remarkable lightweight properties.

Because it is only half the weight and half the cost of traditional masonry fireplaces, Mason-Lite Lightweight Masonry Fireplace Systems help you realize your dream of having a fireplace in your master bedroom, upstairs retreat, or even your outdoor patio, without major building infrastructure reinforcement. The restful flicker and comfortable glow of the fire will provide you with years of treasured memories.

With the help of ICC-ES, Mason-Lite developed the structural testing and performance criteria (AC375) that would comply with the International Building Code (IBC), the International Residential Code (IRC), and the International Fuel Gas Code (IFGC). This allows building officials throughout the US to confirm that Mason-Lite fireplaces meet these stringent codes.

Why Choose Mason-Lite:


  • Lightweight construction with multiple firebox sizes available.
  • Best fit and finish in the industry.
  • Available for Indoor/outdoor, wood-burning, natural, and propane gas systems.
  • Allowed for multi-story combustible floor installations.
  • Superior thermal efficiencies with the highest resistance strength at 28 days.
  • Complies and tested with UL 127 & UL 103 chimney component standards.
  • Optional herringbone or running bond firebrick panels for easy installation.
  • Heat resistant fire tested up to 1700 Degrees Fahrenheit.
  • Less expensive shipping and handling costs.
  • 50% cheaper than a traditional hand-built masonry fireplace.
  • All kit comes complete with Refractory Mortar, Rebar, and T-bar.
  • Limited Lifetime warranty.
  • Made in the U.S.A.


Model MFP39-RM
Finished Opening Dimensions 36" (W) x 21.5" (D) x 30.5" (H)
Total Unit Height 62.25"
Footprint 43" x 28"
Flue Diameter - Class A 12" ID
Clearance to Combustibles* (Sides and Back) 2"
Framing Width 47" (W) x 30" (D) x 64.25" (H)
Floor Area (37 x 28) 8.36 sq. ft.
Fireplace Weight 1787 lbs.
Mortar and Rebar 67 lbs.
Ready Mix 200 lbs.
Metal Chimney weight per foot 10 lbs.
Installation Type Flush Installation / Corner / Internal Wall / Full Projection
Warranty Limited lifetime warranty


Optional Accessories
Click to see details

MFP39SHBL Split Herringbone Brick liner

Mason-Lite offers true firebrick panels for quick and easy installation. 

MFP39FRBL Full Running Bond Brick liner

Mason-Lite offers true firebrick panels for quick and easy installation.

MFPB39 6" Structural Metal Base

Our 6” and 8” bases are used for installations on combustible floors or second-story applications.

MFP4-AK Combustion Air Kit

Because homes are being built so tight, many jurisdictions are requiring additional outside air to make up for negative air pressure. For convenience, the kit comes pre-drilled for this application.

MFP-Arc Masonry Arch

The masonry arch kit consists of 2 pieces that can easily be mortared in to give a custom look.

MFP39-HK Height Kit

This Height Kit consists of a rear wall and two side walls that will increase the height opening by 8" from the standard opening (giving a Rumford look). With the new size, the opening is sure to check the Chimney Size Chart to ensure proper flu size.

12ATGAPD Anchor Plate w/ 12" Damper

Dampers are required for indoor applications. Mason-Lite offers several damper options: metal anchor plate/damper for masonry chimney; cast-iron damper (damper blocks included); anchor plate/damper for metal chimney

Premium Chimney Shrouds

Mason Lite’s Decorative steel and copper chimney pots offer an alternative to unsightly factory flue caps and terminations, improving the aesthetics of chimney tops

Air Cooled Chimney System for Masonry Fireplace
Click to see details
Click Here to Shop for Class A UL103 Chimney System



Attention: You may need a residential building permit to install a Mason-Lite Fireplace. Consult local jurisdictions before you get started!

View full details
  • Researched and ordered my fireplace from US FIreplace Store. Pricing was a fair value however, the customer service was EXCELLENT! I had an issue with the direct vent venting. I called US Fireplace and the correct items were sent out the next day AND Janessa stayed on top of my return authorization and sent me the permissions and documents I needed to return the incorrect item and no cost to me, including return shipping. Overall, I am a very satisfied customer and my fireplace looks and operates flawlessly. I am glad that I selected US FIreplace to source my direct vent fireplace. Thank you for the great service.


    Monteagle, TN

  • I had placed an order, through Lowe's Home Improvement, for an Electric Firebox: Revillusion RBF42. Ordered 1st part of January. Was told I would have it in 3 weeks. When checking to see is it came in, was told it was delayed to 3/15. Was then told is was delayed until 4/25. Waited until 4/27 to check on it. Was then told it was now delayed until August. This firebox was going in a new Sun Room addition. I could not get my final inspection until the Firebox was installed. I went on line and googled for this same product. US Fireplace Store web site was given to me. This was on a Saturday. I call and reached a very nice man. Explain what I was look for. He checked and told me they had 30 of them in stock. I almost fell out of my chair. I clarified with him the product I was wanting. I ask how soon could I get it. He told me it would ship today. Again, was amazed. It arrived on the following Monday. What a pleasure and a relief working with US Fireplace Store and their employees. Exceed my expectations.

    Thomas W.

    Fort Mill, SC

  • Great prices, quick delivery and fast hassle free services on the issue I encountered. I had purchased an electric fireplace unit that would not fit into the existing fireplace space. With one email I was able to get the wrong fireplace refunded and picked up at my home at no extra cost and the new one I purchased and delivered free of charge. Great company.

    John P.

    Denvers, MA

1 of 12
  • Live Chat Support

    No chatbots. Speak with a human. Average response time is 48 seconds.

  • Easy Returns

    Need to return the merchandise? We accept returns for 30 days from the date of delivery.

  • 7 Days/Week Service

    We're here to help on live chat, email & phone. 8:00 AM - 11:59 PM Eastern Time.

  • 100,000+ Products

    America's largest selection of hearth & heating products. Fireplaces, stoves, fire pits, heaters, log sets and more.

  • Pay Over Time

    0% APR is available for 3 and 12- month financing.* See if you prequalify today.

  • Staff Picks

    Check out the Staff Picks collection. See the top products selected by our team.