Intro: DIY Fireplace Mantel Upgrade
This is a cheap way of updating an old fireplace mantelpiece. All you need is:
- A timber sleeper, these are generally quite cheap.
- A circular saw.
- A hammer and chisel
- Some sandpaper
- Construction adhesive and clamps
This project does require that you have an existing mantel and that it's sturdy enough to support the new timber.
The fireplace in this Instructable is not operational. Always check your local code when renovating a functioning fireplace.
Step 1: Cut the Sleeper to Size
The first step is to cut the sleeper to size. Consider the amount of overhang you want on all 3 edges and factor that in. The more over hang you have the easier it will be to install too. I went with around 100mm on the front and 20mm each side.
Once you've cut it to length measure the size of the current mantel and mark that on the sleeper. Get as close to the measurement as possible because ideally you want the sleeper to be force fitted into place. This will help with the glue.
Once I had marked the area that needed to be cut out I marked it so I wouldn't accidentally cut the wrong part!
Step 2: Start Cutting
Next you'll cut strips into the sleeper inside the lines marked earlier. This is best done with a circular saw. Set the depth of the circular saw cut to the height of the existing mantel. The more cuts you make the better, you want to remove as much material with the saw as possible. I cut too few lines and in retrospect I wish I had made more.
Make sure to also cut the perpendicular lines. These can go past the line because you won't see these underneath the sleeper. If you want to keep within the lines you can but it just means more work in the chiseling stage.
Step 3: Remove Waste Material
Now the you have the relief cuts you can attack the piece with a sharp chisel. This step took a long time but be patient and flatten the surface as best as possible.
The reason we use construction adhesive in this process is because it's far superior at bridging gaps compared with wood glue. So you need to get the inside of the sleep as flat and square as possible but you can get away with 10mm or less worth of gaps.
Make sure your chisel is very sharp for this step. You'll most likely be cutting across the grain and a sharp edge makes this enjoyable.
Step 4: Sand and Finish
Because the sleeper will most likely be rough it will require a fair amount of finishing. I used a hand plane to help flatten the wood then used a belt sander.
After the sanding you should finish the timber now. In my case I stained the sleeper a dark brown.
Step 5: Attach the Sleeper
You'll most likely need to strip the existing mantel if it's timber. To this a heat gun works really well, or you can sand/chisel some gouges into the wood. All you're looking for here is some bare timber for the glue to adhere too.
Liberally apply glue to both the existing mantel AND the sleeper to ensure good coverage. I find it best to make some pools of glue to ensure good contact. Spreading a film work great if both surfaces are flat and square but this will most probably not be. This is why we're using construction adhesive in the first place.
Remember, you aren't clamping the sleeper to the fireplace, it's glued onto the existing mantel. I used a 2x4 to spread the pressure along the entire sleeper. I also drove a couple screws through the sleeper into the existing mantel as an added clamp, but the glue will do most of the work.