Masonry Fireplace Door Buyer's Guide
Masonry fireplace doors may be the answer to all your problems. Do you have a beautiful fireplace but never actually use it because the heat always goes out the chimney? Maybe you can't trust your pets to stay out of the still warm ashes. Or, is there an all-too-curious child in the family? Plus, they'll add a little extra style to your hearth and home.
Adding masonry fireplace doors help keep the heat inside your home and cold air out, all while keeping embers inside the fireplace. Doors will also prevent curious loved ones from burning themselves by accident.
This article will cover masonry fireplace doors as installed on a site-built fireplace. This does not include prefabricated fireplaces, which have a series of doors all to themselves.
You can install masonry fireplace doors to cover the opening of a wood-burning fireplace or one retrofitted to use a gas burner. The doors do not prevent the use of gas logs in a masonry fireplace. The fuel type will change how the doors operate, but the basic designs do not vary too much.
The Basic Components of the Door
Manufactured doors meant for masonry fireplaces have three main components. These components include the mounting frame, glass/screen doors, and the attachment hardware.
The mounting frame serves as the backbone of the door assembly. It can either be three-sided or four-sided, depending on the design of your fireplace.
If your fireplace's hearth extends in front of the fireplace, you need a three-sided frame. This means the door assembly rests on the hearth. In contrast, if there is no hearth but a "floating" opening, you'll need a four-sided frame. It conceals any gaps that may appear at the bottom of the door assembly.
Depending on the style of doors, the frame can either be very minimal (about 1") or quite wide (about 6"). Designed to cover the fireplace opening, the frame also holds the weight of the doors. In some cases, the frame has strips of insulation to seal between the frame and the face of the fireplace.
Glass and Screens
The glass or screen doors are the most functional part of the door assembly. Unlike doors on prefab fireplaces, masonry doors have a broad range of options. In addition to the bi-fold and cabinet-style doors available for prefab models, you can order glass panes in a variety of colors and tints.
Many models offer the availability of mesh panels that can attach behind the glass panes as well. This can be a sliding mesh curtain or solid mesh panels that swing out like a cabinet door. There are also some door assemblies that offer solid glass panels that slide back and forth along a rail. These function much like a barn door.
The attachment hardware holds the door assembly to the face of the fireplace. It carries the weight of the doors while they're open. The most common hardware consists of a pair of upper lintel clamps and a pair of lower angle brackets.
Each upper clamp consists of a pair of 90-degree "gripper" brackets and a long threaded rod. The bracket assembly attaches to the metal lintel bar - a flat steel bar that holds the weight of the masonry above the fireplace opening. As the threaded rod is tightened, the 90-degree brackets clamp and "pinch" the lintel, holding the doors in position.
The lower brackets are 90-degree angle brackets. They screw into the base of the frame and attach to the floor of the fireplace. They require drilling into the fireplace floor with a masonry bit. They also need an anchor to receive the fasteners.
The configuration and operation of your masonry fireplace doors depend on the fuel type used for your fireplace. Along with the countless frame and glass options available, many doors offer air-limiting gaskets or air controls to feed the fire.
When not equipped with gaskets, masonry doors function much like prefab doors. They have a small amount of space (approx. 1/8") between the glass panes. This space allows the pull of dilution air from the room into the fireplace while it is operating. The diluted air keeps flue temperatures down and keeps the glass cool. Although some models of glass doors can handle higher temperatures, they can be fitted with door gaskets, too!
Door gaskets limit the air flow into the fireplace, creating a slower and longer burn. In 2009, the International Energy Conservation Code (IECC) enforced new codes for door gaskets. The IECC required the installation of door gaskets for all new masonry fireplaces in certain areas.
This policy created issues as not all masonry fireplaces were equipped to handle the higher flue temperatures. The code was amended with the release of the 2012 IECC version to end the regulations on gasketed doors. In conjunction with the use of gasketed doors, combustion air provisions also ensure safe operation.
Combustion Air Provisions
There are a couple of options to allow combustion air to enter the fireplace while it is in use. The first provision, stated in the 2012 IECC code, pertains to the installation of a dedicated outside air source for combustion. In short, this is a pipe that leads to the outdoors to draw fresh combustion air for the fire.
This dedicated source of dilution air ensures the fireplace maintains safe flue temperatures. For older fireplaces without an external air source, the fireplace doors can have a combustion air inlet of some sort. This usually consists of a riser, which is a panel placed at the base of the doors that has vents. These vents allow a limited room air to enter the fireplace chamber during operation.
Without an appropriate air source in use, gasketed door assemblies must remain open during operation. Shutting the doors can elevate flue temperatures to dangerous levels and lead to a thermal breakdown of the doors.
But why would a customer want a set of gasketed doors? The reason has to do with heat loss and general efficiency.
In an ideal situation, your masonry fireplace will have a set of fireplace doors with a dedicated source of outside combustion air. The air source supplies a steady feed of air, allowing you to enjoy the fire with the doors closed. The fire heats the glass, and it then radiates heat into the room. This reduces the amount of air lost from the home due to negative pressure. It also increases the efficiency of the appliance. Even without an external air source, the amount of air lost from the home is reduced with gasketed doors.
Masonry Doors for Gas-Burning Fireplaces
So, how do fireplace doors function on gas-fueled models? We're glad you asked because the information presented above pertained to wood-burning units.
First, you should never use gasketed doors with gas burning applications. A sealed combustion chamber with restricted air flow creates intense heat that can damage the gas burners and valves.
Gas burning applications use masonry doors as a decorative element only. So, when leaving the doors open on a gas appliance, you will not need protective screens as with a wood-burning applications. Gas fireplaces do not produce sparks.
For door assemblies without gaskets, the operation is like prefabricated doors. The doors must be fully open or fully shut during operation. Leaving them half open causes turbulence, leading to billowing smoke or fire instability.
You may wonder how to choose the correct size door for your fireplace. Manufacturers will specify an ideal width range for non-custom doors. For example, a non-custom door assembly with a glass width of 35 inches may have an outer frame that is 43 inches. Because of this, the manufacturer gives a range of sizes the door can fit.
A door with these dimensions can fit a fireplace from 36 inches wide to 42 inches wide. That's because a 36-inch wide opening prevents the masonry from being seen at the edges of the glass. But, it still allows the perimeter frame to overlap the fireplace opening by 1/2 an inch on either side. The actual ranges will vary from model to model, but this is a common range.
The same concept applies to the height of the door as well. But, the range will be narrower for a three-sided door assembly since there is only an upper frame to work with. For most four-sided assemblies, the amount of overlap space around the edge of the fireplace is equal. This is because the perimeter frame is generally the same width all the way around.
Custom vs. Standard Masonry Doors
Some manufacturers offer a standard series of masonry doors. These are cost-effective, simple, and durable with low maintenance. They usually feature only one or two color options, use bi-fold glass, and fit a variety of sizes. Standard masonry doors are for consumers who need a fireplace door but aren't too concerned with aesthetics.
Custom doors open up a whole new realm of possibilities. Yes, they are more costly than the standard masonry doors. But, they allow a huge range of custom finishes, handles, metal overlays, glass colors, screen types, and frame widths.
The process of ordering custom doors is more complex than the process for standard doors. You'll need exact measurements to get the necessary components. Depending on the extent of customization, you may need to submit a template of the opening. A template is needed for arched fireplace openings and for some stone finishes.
Standard vs. Custom Lead Times
The difference in lead times between standard doors and custom doors depends on manufacturing. Standard doors consist of a handful of models manufactured to fit the most common sizes of masonry fireplaces in the field.
Because there are no custom steps involved, the manufacturer often keeps some models in stock. These usually ship the same business day. Even if standard doors have sold out, equipment is already in place to manufacture more within 5 to 7 business days, in most cases.
The manufacturing lead time for custom doors can be 4 to 8 weeks. This is depending on the manufacturer and complexity of the door assembly. Custom doors involve custom painting, coating, or anodizing of door frames. It also includes custom glass tinting, glass panels, and frame dimensions.
Arched doors are especially challenging to make. These are the ones that need a template of the opening to ensure the arch is the correct radius from the sides. Due to the extra steps required in manufacturing custom parts, custom doors simply take longer to produce.
Custom Door Options
Customized doors offer a wide selection of options for almost every part of the door. In the next section, we explore the wide variety of choices you can make when it comes to customization.
Each custom door style is usually available in many types. This gives a second layer of customization to the look and operation of the doors. While the perimeter frame remains the same for each series, you have the option to select cabinet style, bi-fold style, or sliding door options.
These options vary by style, but at least two of each are offered. You'll also have an option to select "frameless" glass or glass panes with a perimeter frame. Lastly, some versions will allow various metal overlays. These overlays change the look of the doors, such as an Art Deco style or Mission Style.
This is where the custom doors really shine. As many as 30 different finishing options are available for each door style. Some finishes are coated to the surface as a high heat paint. Or, the metal itself may be anodized to achieve the desired appearance.
Some basic finishes come standard, while more complex finishes may incur extra costs. Examples of a standard finish include polished chrome or a nice traditional black. An example of a custom finish is more like a hammered bronze.
Another option for a custom door set is the handles that operate the glass assemblies. Most models will have the option to have the handles match the frame color or they can be a different accent color.
There are at least five different handle styles offered for most models. Some handle styles include barrel, classic, basket, radiused, etc.
Glass and Screens
You can also choose between two types of glass - tempered or ceramic. Tempered glass absorbs heat and then radiates it to the room. Ceramic glass allows infrared heat to pass through. You'll also have various tint options, such as bronze, grey, or black tint.
For mesh screens, you also have a few options. There is a standard draped style, a sliding mesh curtain, or gate mesh panels that swing outward like a door.
Note: No matter which glass type you choose, always remember that a fireplace glass will get hot to the touch. This includes the time while the fireplace is in use and for some time after the fire goes out.
The materials used to construct the door depend on the door style. So, these materials are predetermined and do not change. In other words, you will not have the option to blend different materials into a single door.
Doors that feature a simple or minimal design are usually aluminum. This is because aluminum is more pliable and easier to customize, keeping the cost down. While lighter in weight, the aluminum doors are still durable and can last for decades.
Doors that feature complex overlays or angles for a more stately appearance are built from steel. Naturally durable, steel also allows forming into more shapes and angles.
Due to the fragile nature of glass, masonry door assemblies are carefully packaged. They are shipped in durable flat cartons with double walls and large quantities of packaging foam. Glass panes are shipped free of the door frame. They are wrapped with insulating packaging material to protect them from shock. The entire perimeter of the box is lined with energy absorbing corner braces as well.
Even with all this protection, damage can occur if the carton is not handled with care. So, it's important to inspect the door frame for scuffs or marks when unpacked. Verify that your tempered or ceramic glass panes are intact and that any custom tinting is not scratched or scuffed.
All but the largest and heaviest door assemblies can go parcel. If a door assembly is larger than 48 inches wide or 85 pounds, the manufacturers usually choose to ship LTL freight to guard against damage.
For a fireplace constructed of a non-brittle stone, it's best to draw an outline of the doors on the fireplace. Then, use a grinder with a masonry blade to cut down and level the irregular surface of the stone.
You'll need eye and ear protection for this process. But, it is not recommended for slate, shale, or other stones materials that can shatter easily.
If cutting the stone is not possible, adding a smooth layer of refractory cement along the stone where the door assembly will mount is an option. A good refractory cement will be heat resistant with a strong hold against the stone surface. This helps create a firm and smooth surface to mount the doors.
Shutting the Door on Masonry Doors
Even the most irregular masonry fireplace can have doors added. Make your masonry fireplace safer, more efficient, and more visually appealing with a set of masonry fireplace doors.
eFireplaceStore's NFI Certified Technicians are always ready to help you figure out how to make your home fireplace the safest it can be.
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Fireplace Doors for Masonry Fireplaces Q&A with the NFI Certified Specialists* Please Note: All customer questions are answered by our NFI Certified Specialists free of charge!
from Victoria, BC asked:
October 10, 2020
If doors with gasket cause a longer and slower burn, does this not create a creosote problem?
This is dictated by a number of things, including chimney size, height, wind conditions, pressure issues in the home, etc. Depending on the fireplace application (manufactured vs. masonry), there are a variety of issues to consider.
Tyler M. - NFI Master Hearth Professional
on October 12, 2020
from Dover VT asked:
August 17, 2019
Can I spray paint with high heat paint over brass on glass bi-fold doors?
Yes, but you would need to prep the brass surface for the paint first.
on August 20, 2019
Customer Images of Fireplace Doors for Masonry Fireplaces