Adding a fireplace to your home can be a great way to add value as well as a bit of extra warmth. If you don’t want to pay to have someone else do it, though, you’ll need to look into how to install one on your own. While this can be a major project, it is one that you can accomplish with the right tools and the right guide.
Start with a Plan
While you are absolutely going to have to make a few major choices depending on the fuel type of your fireplace, the truth is that every type of fireplace has a handful of features to keep in mind as you work on your project. You will, for example, need to remember that the actual construction of virtually every fireplace that you buy is going to be roughly the same – that means a modular design is made of sheet metal and has plenty of operational space. You’ll also need to remember that all of these units are going to rely on a firebox that’s suspended from the outer fireplace, which allows the unit to better radiate heat. These are going to be major factors to keep in mind as you build.

What this really means for you is that the size of the fireplace you’re installing isn’t necessarily going to reflect the dimensions on the box. The width of a fireplace usually refers to the width of the firebox chamber – there’s always more space needed to keep that layer of air available around the firebox. As such, you’re going to want to realize that you’ll have to account for a few more inches not only on either side of your fireplace but also above your fireplace. If you’re looking at an advertised width of forty inches, for example, your goal should be to have added two inches of clearance space on each side of that box.
The good news here is that you really are going to get most of the information that you need from reading your fireplace’s installation manual. It’s going to give you all kinds of information about clearances and installation procedures, as well as safety tips that you can follow to ensure that you do the job right. While this guide is absolutely going to help to walk you through the installation process, that doesn’t mean that you can skip the homework before you start.
Notes on a Gas Fireplace
If you’re going to install gas, you’re going to be dealing with a much more complex installation process. It’s recommended that you spend some time doing some research to figure out exactly what kind of space you have available and what you need from your fireplace so that you can get the most out of your new installation. The good news, though, is that you’re going to run into an awful lot of information while doing this research and that you will be able to use it all later. this includes information about the kind of venting components that you need – a vital part of the fireplace installation.
Note that you’re also going to need to make sure that you know where your gas and electrical lines are. If they’re not near where you want to have your fireplace installed, you’ll need to look into having them routed to this area. As you might expect, you’re going to need to get some quotes from a variety of different professionals before you start the installation process.
Notes on Wood-Burning Fireplace
Installing a wood fireplace is also going to have its own particular challenges. All wood fireplaces have to be vented vertically, for example, and you’ll never have to worry about electrical or plumbing connections unless you buy a unit that has some sort of special features.
With that said, you will be dealing with a unit that tends to burn hotter and longer than its competitors. Most wood-burning units need a much larger chimney and have to have extra space for heat radiation. It is vital that you pay attention to the instructions to learn exactly how much space you’re going to need for clearances as you build up your wood-burning fireplace.
The Building Process
Framing
You’re actually going to start your project by making sure that you have a firm foundation in place. Fireplaces are heavier than you might think, and they can absolutely ruin a floor if they’re laid on one without preparation. For the purposes of this guide, though, we’ll assume you’ve already finished that step.
Now that you’ve got your foundation in place, you’ll put together a frame for the unit. As we discussed earlier, you’re going to need more space here than what’s on the front of the box. Fortunately, your instruction manual should tell you everything you need to know in terms of clearances.
Once the wooden frame is built, you can start installing the fireplace. Depending on the type of the fireplace, you’ll either nail or screw in the external jacket to the frame, and then you’ll just follow the instructions in your guide to learn where each piece goes and how each piece will be attached.
This is also the point at which you need to start thinking about how you’re going to finish up your fireplace. Most people are going to use drywall for the bulk of the process, but many do choose tile or stone to give their fireplaces a little bit of extra aesthetic appeal. Regardless of what you ultimately decide to use, you should definitely ensure that the material isn’t so thick that it pushes out too far from the finished fireplace.
Venting
Venting is perhaps the most important part of assembling your gas fireplace. If you mess this part up, you’re going to get dangerous smoke blowing back into your home. As such, you need to make the installation of your various venting components incredibly seriously. You’ll need to follow the instructions carefully during this step, ensuring that you attach your flue color correctly and that you take steps to get rid of any of the packing materials that might be inside. This also means removing caps and tossing out insulation if it comes with the venting components.
The step by step process here is fairly simple. Install your vent collar correctly and ensure that it is configured in the right way, then start installing the pieces of pipe necessary for the system to work. You’ll use an appliance sealant here as well to keep things in place, but the most important thing you’ll do is to make sure that you carefully twist each piece so that it locks in place. Pull-on the pipes to make sure that they stay in place, then use your sheet metal screws at each connection point to hold things securely.
This part of the process is more tedious than anything else, as you’re going to keep doing the same thing over and over again – insert, twist, check, and then screw in the scores. It’s easy to get distracted, but make sure that you’re checking each piece individually and that you keep all of your clearances in mind as you move along. It’s also a good idea to add a bit of security by securing the pipe to studs at five-foot intervals with HVAC strapping, which will keep it from moving too much.
At the top of your venting with being your firestop. This will be installed at the ceiling level of your build and should usually be nailed to a set of 2×4 pieces of lumber. You’ll absolutely want to check with your local building codes to see if there are any other steps, as some areas do have incredibly specific rules about how firestops are to be secured.
Venting for Wood
Venting for wood is going to be a little bit different. You’re going to need to build a wider interior chimney, albeit not necessarily one that has to be built up outside. You’ll need the extra space to help with the excess heat of a wood-burning unit, but the actual installation process isn’t all that different than what you did with the gas fireplace.
As with most parts of the building process, most of what you’re going to look at here is clearances. The clearances for here are going to vary quite a bit depending on what kind of fireplace you choose to use, so make sure that you consult your instruction manual for the precise instructions in regards to what you need for clearances as well as more specific construction necessities.
Generally speaking, you’re going to start by figuring out which way the chimney is oriented. Once this is done, you’ll start assembling the inner section of the chimney by sliding the end of this part into the fireplace’s inner collar. Don’t be afraid when you hear a snapping sound – this is actually a sign that you’ve done everything correctly. You’ll do the same thing to install the outer section.
Now that you’ve got both sections installed, you’ll follow those same procedures for securing the piping that was discussed above. You’ll only be puncturing the outer wall sections here, with spacers in place to make sure that you don’t hit the inner walls and that the inner walls of your chimney stay in place as you secure the outer sections.
Passing Through the Roof
Now you’ve made it to the roof. Congratulations – you’re going to get to play around a little bit with personal preferences. In theory, you can really just leave your piping exposed above your roof at this point. Sure, you’ll need to seal it off with some flashing and ensure that it’s in a good position, but building a chimney isn’t the kind of absolute necessity that many might assume.
One of the things that are going to be a little frightening to the average homeowner is the idea of cutting into the roof. You’ll be able to tell where your pipes hit the roof by using a level to see where it is pushing up, and from here you’re going to simply cut a hole that’s big enough to allow all of your necessary clearances. If you’ve got a particularly steep roof, you’re generally going to need to cut a bigger hole.
From here, it’s time to start working on the flashing. That means keeping the flashing tucked under the upper shingles with the shingles on the sides running over the edges. You’ll be nailing this flashing into place so that it stays still, but much of the work is going to be done by your roofing sealant of choice. Once the flashing is in place, you can finish up the job by adding a storm collar (which also has to be sealed) and then capping off the entire build with an actual cap.
Electrical and Plumbing Connections
So, what do you do if your fireplace requires some kind of power or plumbing connection? It’s a more common question than you might think, especially when you’re installing higher-end fireplaces. The good news is that you’re mostly going to follow the same instructions that you’ve followed before. The biggest thing you’re going to be dealing with at this point is making sure that your existing electrical and/or plumbing lines are able to be connected to your new fireplace. This is most common in systems that have exhaust fans or electrical starters, but there are many reasons why you might find yourself dealing with these next steps.
Again, the good news is that your fireplace is going to come with instructions about how to do this bit. If you need electrical service, you’ll have a diagram of the fireplace’s junction box. You’ll simply follow the directions to attach the wires as needed.
It’s always a good idea to follow the best practices as you make your electrical connections. That means using approved tape and wire nuts, as well as fittings that will allow you to keep each one of your connections secured. If there are any loose wires, they also need to be secured with wire staples. Keep in mind that sometimes you will have to call a licensed electrician, there’s just no way around it.
You likewise need to pay careful attention to how you connect any of your gas lines. This means only using approved fittings and connectors – generally larger flex lines, with pipe tape at any connections. If you aren’t absolutely certain about your ability to connect your gas lines, you definitely need to think about working with a professional to get this part of the job done.
Finishing the Installation
The good news here is that you don’t need any special skills to finish your fireplace. This is really a process that’s going to be exactly the same as any other finishing job, with the same basic drywall or tiling skills that you’ve used for other projects. The only big thing to keep in mind is that your drywall can’t touch the metal of the fireplace so you’ll have to get a special kit for this job.

If you’re using non-combustible tile or stone, you can cover the metal of the fireplace without worry. If not, you can use a fiber or concrete backer board to give you the layer of extra protection that you need. remember that you can’t cover up anything that will vent out smoke or heat and that you’ll absolutely need to make sure that no part of your fireplace opening or control panel can be covered by your finishes. Again, your installation manual is going to give you a great deal of valuable information about what can and cannot be covered on your fireplace.
It’s vital that you pay attention to your instructions during these final steps. While you’re probably not going to learn too much if you are already a DIY pro, you’ll still be able to avoid some mistakes by paying attention to this information. If you’re new to DIY work, though, there’s virtually no way that you can finish this project without paying attention to the manual.
You should also know that there’s never a reason to avoid getting a professional consultation about the parts of the process with which you are not comfortable. It’s always a better idea to get some help than to ruin a part of your build because you were too proud to consult an expert. Though this is a project that you can do on your own, you should definitely reach out whenever you feel like you are out of your depth.
Frequently Asked Questions
How much does it cost to add a fireplace to an existing home?
Adding a new fireplace to an existing home can cost anywhere between twelve hundred and five thousand dollars, depending on the amount of work that the individual does on his or her own, the type of fireplace chosen, and the types of finishes he or she chooses for the project.
Can you install your own fireplace?
Yes, you can install your own fireplace. It’s not always an easy process, but it is one that can be done by those who feel confident in their DIY skills.
If you are looking for something more modern, there are also newer and easier options for you.
Can you install a wood-burning fireplace in an existing home?
Yes, you can. You’ll need to check out various zoning rules and figure out if you need a permit, but you can undertake this process if you feel like it’s the right choice for your home.