How to Install a Fireplace: The Ultimate DIY Guide
Installing a fireplace can be costly and potentially dangerous, with gas fireplace installation even more challenging. By the end of this brief article, you'll have the information and resources necessary to install a fireplace safely and economically.
This article will simplify the fireplace installation and guide you through every aspect. Whether you hire a contractor to install your fireplace or do it yourself, please take full advantage of our free fireplace installation checklists to ensure you get the job done right.
Planning and Considerations
Regardless of the fuel type, there are common design aspects of all factory-built fireplaces that must be taken into consideration when planning a DIY installation. Factory-built fireplaces are a prefabricated sheet metal system that relies on clearances to combustibles to operate safely. The modular design offers a cost-effective alternative to a traditional site-built masonry fireplace.
Wood, gas, and electric units will all utilize an inner firebox chamber suspended by metal supports from an outer fireplace jacket. The air space between the inner and outer jackets and the unit's ability to dissipate heat allows prefabricated fireplace installation into a combustible enclosure framed from commonly available dimensional lumber.
As you may have surmised, the advertised width of a wood or gas fireplace will almost always be the physical opening of the inner firebox chamber. The air space and outer fireplace jacket mean the appliance will need additional space to fit into your intended location. For instance, a wood-burning fireplace with an advertised 36-inch wide viewing area may have a framing dimension of 40 inches wide overall. Because heat naturally rises, additional space above the fireplace is also required.
Most fireboxes use external metal standoffs to maintain proper spacing. A detailed instruction manual covers many pertinent construction details, as with any home appliance installation. The manual will include the framing dimensions, venting requirements, clearances to combustibles, and other preparations needed before installation. Homeowners must read and understand these instructions to ensure safe and successful operation.
Before making a fireplace purchase, it is recommended to contact the NFI certified techs at eFireplaceStore to discuss your expectations from your fireplace purpose.
A gas fireplace will be the most complex type of installation. Before making a fireplace purchase, we recommend contacting the NFI-certified techs at eFireplaceStore.com to discuss your expectations for your fireplace purpose. The sheer number of designs and different venting types can be overwhelming initially. However, narrowing the selection down to a unit that will fit your requirements can typically be accomplished in a single phone call. In the long run, making that call will greatly help your gas fireplace installation. It is important to know the overall width, depth, and height of the intended installation area and the overall ceiling and roof height.
Most gas fireplaces will list the approved venting components in the instruction manual; the fireplace must use only those components. A major listing agency tests and approves those venting components to ensure safe fireplace operation. A tech will be able to assist you in putting together the needed list of components. You must also determine how a gas line and electrical service if needed, will be routed to the installation location. Collecting quotes from reputable local businesses for this initial work will leave you in a much better position to determine the overall cost and timeline of the project. After completing the preliminary work, the installation itself can commence.
Framing the Fireplace
After establishing the projection, you can push the unit into the framed opening and nail or screw it into position. Although the framing of the fireplace opening can begin before the appliance has shipped to you, we highly recommend having the appliance on-site to check against before commencing the installation.
Follow the framing instructions supplied with the unit to build a framed opening that meets the sizing requirements specified by the manufacturer. Using 2 x 4-dimensional lumber and a 2 x 8 or 2 x 10 header is common. Most manufacturers allow the fireplace to sit directly on a combustible floor. You can also build a combustible platform at this time to raise the unit within the wall opening if you wish. Pay close attention to any side or overhead ceiling clearances the manufacturer outlines.
At this time, you should also consider the finishing material thickness. Many installations are finished with standard 1/2 inch drywall up to the edges of the unit, but tile veneers and stone veneers are also popular. Whatever the thickness of the material, you must ensure the unit projects forward from the framed opening enough to compensate for the thickness of the finishing material if you are looking for a flush installation. For example, if you plan to install a 3/8 inch thick tile over a 1/2 inch thick cement board, the fireplace will need to project 7/8 of an inch from the facing of your framed opening. This will ensure that the tile will be relatively flush with the face of the unit when finishing is completed.
Some manufacturers provide nailing tabs at different depths on the appliance to help compensate for the setback you need. If the tabs don't provide enough projection, the unit may need to be shimmed as you install it. Ensure the unit is plumb and level before nailing it into position. You can use cedar shims to make adjustments if needed.
Installing the Venting Components
The installation of the venting components should come next. Almost all gas vent pipes will use a twist lock attachment method. Depending on how you are venting the appliance, you may need to uncover or rotate the venting collar on the appliance for your application. For instance, Superior direct vent gas appliances will have the vertical flue collar covered by a plate and the back collar covered by a cap. If you are venting the appliance vertically, you'll need to remove the plate and discard the insulation and pipe plug within. If venting horizontally, you'll need to remove the rear cap similarly.
Other designs use similar caps or lids for the unused flue collar, while a few designs have a dedicated top or rear vent configuration. After configuring the vent collar properly, you can install the first piece of pipe. Before attaching it to the appliance, you should apply a direct vent appliance sealant bead to the inner pipe wall. Ensure that the dimples on each pipe align with the channels on the flue collar, and firmly twist the pipe clockwise until it ceases to rotate. Double-check the connection by pulling upward on the pipe. If any dimple pulls loose, try again to create a secure connection. Secure the pipe by installing three self-tapping 3/4 sheet metal screws at this connection and every subsequent connection. The screws should only be allowed to penetrate the outer wall of the pipe.
Continue your installation with each section of the vent pipe, repeating the twist, check, and screw method for the entirety of the run. Check the pipe run to ensure that you always maintain the minimum required clearances to combustibles. We recommend securing the pipe run every 5 feet by wrapping it with perforated HVAC strapping and securing it to adjacent studs. This will limit the amount of lateral motion in the pipe run. Most manufacturers will also provide a sheet metal firestop that should be installed at the ceiling level.
You can install the firestop after reaching the ceiling level. Installing 2 x 4 lumber immediately adjacent to both sides of the pipe is common practice to give the firestop plate something to nail. Some jurisdictions will also require that you enclose the top of your framed fireplace enclosure with a plywood or oriented strand board. If this is the case, you must cut the plywood or strand board to the dimensions of your enclosure and nailed into place atop 2 x 4 scabbing.
Passing Through the Roof
Depending on your preference, the vent pipe can be exposed above the roof or boxed into a decorative chimney chase. If left exposed, use a roof flashing to seal the termination. The image above depicts a venting run that has penetrated a wooden firestop and uses metal strapping to support an offset in the pipe run. The vent pipe can be exposed above the roof or boxed into a decorative chimney chase. If left exposed, you will use roof flashing to seal the termination.
As the pipe installation nears the roof decking, you can use a plumb bob or level to determine the penetration point. Using a reciprocating or jigsaw, cut a hole large enough in the roof to ensure the pipe can pass through and meet all applicable clearances. Please note that the steeper the roof is, the longer the hole parallel to the roof slope will be.
Installation of the flashing will follow the normal procedure for all roof flashing, with the leading edge of the flashing tucked under the uppermost row of shingles, the adjacent shingles lapped over the flashing edges, and the trailing edge of the flashing atop the shingles. You can nail the flashing into position with 1 1/4 of longer roofing nails and then seal with a high-quality mastic or polyurethane roofing sealant. As you affix and run the last section of the pipe through the flashing, you should attach and seal the storm collar around the pipe. You should install the cap last and screw it into position as with the previous pipe sections.
Electrical and Plumbing Connections
Wood-burning appliances follow much of the same design and installation requirements as gas appliances, but some differences exist. Upon completion of the venting installation, the electrical and plumbing previously installed by a local professional can be connected to the appliance. If your appliance requires electrical service for the ignition system or circulating fan, install the supplied junction box inside the unit. The wiring diagram within the owner's manual outlines this. Following the diagram, connect the wire leads of the new circuit to the wire pigtails supplied with the unit.
Make each connection using a NEMA-approved wire nut and electrical tape. Most units will usually provide an anti-strain fitting to secure the wiring connection. Secure any loose wire from the circuit with NEMA-approved wire staples. The gas connection to the unit should only use an approved flex connector and fittings. Most appliances require a 3/8 inch or larger flex line. Use Teflon pipe tape or pipe thread sealant for all connections except for the flex line connections. Consult a licensed professional if there are any doubts about one's abilities with electrical and plumbing connections.
Wood-burning fireplaces will always be vertically vented and won't require any sealant at the flue collar connection. They will also not require an electrical or plumbing connection in most cases. Installing a circulating fan or a gas starting aid would be an exception to this rule.
Because of the potential for extremely high temperatures, wood-burning chimneys are also much larger in diameter and will sometimes require additional combustible clearances. As with gas-burning appliances, it is very important to read and fully understand all installation instructions before purchasing. The technicians at eFireplaceStore.com will be happy to provide you with copies of any installation instructions needed for prior review.
Assembling the Chimney
Pay strict attention to the vent pipe clearances required. Most wood-burning fireplaces use an air-cooled chimney system with independent inner and outer walls. Once you have completed the framing and mounting of the appliance, as outlined in the earlier part of this article, the assembly of the chimney can begin. Most wood-burning chimney systems will use a hem and lance system instead of the twist-lock system used by gas appliances. A label on the outer wall of each chimney section will usually indicate the orientation of the chimney.
Once you've determined the orientation, separate each section's inner and outer pieces. Beginning with the inner section, firmly insert the end of the section into the inner collar of the appliance. When enough pressure is applied, the section should emit an audible snap, indicating it has locked into place. Pulling upward on the pipe section will verify that it's indeed snapped into position. Repeat the process with the outer wall of the pipe section.
After installing both sections, follow the same procedure as with the gas appliance by installing three self-tapping 3/4 sheet metal screws at this connection and every subsequent connection. You must puncture only the outer section despite the independent inner and outer wall construction. The internal spacers between the inner and outer walls will ensure that the inner sections remain in position.
A few high-efficiency wood-burning fireplaces will use a twist lock chimney system that has inner and outer walls made together, much the same as direct vent gas appliances. In this case, the assembly procedure mirrors that of a direct vent gas appliance. As with gas appliances, you must utilize a firestop at the top of your enclosure and install the proper flashing for your chimney system. Pay strict attention to the required vent pipe clearances.
Finishing the Installation
Finishing your fireplace enclosure will resemble completing any other drywall, tile, or veneer project. For a drywall application, you will need to affix the drywall sheets to the enclosure with coarse thread drywall screws or nails. Drywall cannot touch the metal chassis of the fireplace, and trim kits are available to cover the resulting gap. Stone or tile can be applied to the wall as well.
Secure a concrete or fiber backer board to the studs first, as with any other installation. It's okay for noncombustible tile and stone to cover the metal chassis of a fireplace as long as the fireplace design has a smooth face with no louvers or grills. You cannot cover louvers, grills, and other vents. The finishing material also can't cover any part of the fireplace opening and should not be allowed to impede access to any control panels for a gas fireplace. Each fireplace manufacturer and model is different, so it's essential to understand the appliance's finishing section of the manual.
Each fireplace manufacturer and model is different, and reading and understanding the appliance's finishing section of the manual is very important. While a skilled DIY homeowner should be able to take the information provided in this guide and work through the process with little difficulty, a new homeowner may need more guidance to move forward.
Consulting with a local professional regarding any uncertainties over structural framing, plumbing, or electrical installation is always recommended. We at eFireplaceStore.com are always available to answer any questions regarding an appliance you're considering or any installation questions that may arise. We sincerely wish to see each of our customers completely satisfied with their fireplace selection and installation process.
Need More Help?
Please read our other helpful articles on topics like Choosing the Proper Venting for Your Fireplace and Common Mistakes that Fireplace Contractors Make.
Whether you have decided to install your new fireplace yourself or opted to go with a licensed contractor, don't forget your free fireplace installation checklists. They're sure to assist you at each stage of the process.
If you still need additional guidance, please contact one of our certified fireplace specialists, and they would be more than happy to help you.
