Introduction: Decorative Cardboard Fireplace

This Christmas, with our son now old enough to understand and "appreciate" the holiday, my wife and I decided that we needed a fireplace for Santa Clause. Since we live in a rented house with no fireplace, this at first proved problematic, until I remembered the piles and piles of cardboard boxes we had laying around in the garage-turned-storage-shed.

So, flexing my creative muscle, and working carefully around a very inquisitive 3-year-old, we decided to make our own fireplace. You can see the before and after pictures above, in the next steps you'll see the process in-between, enjoy!

!!! Cautionary note: You will be working with sharp objects, so please be careful! Whenever possible, cut away from yourself and NOT toward other people. Also, there are copious amounts of glue involved, and some weights, so don't get yourself stuck and drop a weight on your feets, that would hurt! That being said, lets move on!

Step 1: Materials

So, some of the basic items you will need:

1. Cardboard, lots of it! The flatter, less wrinkled and bent the better. For some parts I used double walled boxes, for others I used single walled boxes. Hindsight being 20/20, it would have been better to use all single walled boxes

2. Box cutter, with a nice sharp blade. Wouldn't hurt to have an extra blade or two on hand just in case.

3. Duct Tape

4. Ruler

5. Measuring tape

6. Sharpie or pen

7. Wood Glue, lots and lots of Wood Glue. In an early project I found that Elmer's Wood Glue works great on cardboard - it adheres quickly and bonds expectionally well!

8. Brown shipping paper. This started out as a good idea, but turned out to be more of pain than the asthetic appeal we had hoped it would bring

10. Paints: red, grey, brown, black, whatever color you want to paint your fireplace

11. Paint brushes and drop clothes - we used a camping tarp.

Other items that came in handy:

Two 20lb dumb bells to weight down larger sections as the glue dried, but you could also use stacks of books or jars of spare change (which were also used) or anything that will put pressure on a piece

A piece of old plywood - to spread the weight

Binder Clips!!! These things are a life saver when it comes to holding smaller sections together. Way better than sitting there for 15 minutes...

A multi-tool, any multi-tool will work.

Step 2: Decide on Your Basic Shape, Start Measuring and Cutting!

The fireplace would have two larger vertical columns, on top of a raised platform, and capped with a slightly overhanging mantle.

In the pictures above you can see how the basic vertical columns were boxed up. Granted, the diagram is way more clean than how the boxes turned out, especially the ends, but hey, it was all covered up nicely.

It was estimated that about three-ish feet tall by four-ish feet wide would be nearly perfect for the wall space we had decided to put it against. Of course your own design may vary.

Once the two vertical columns were cut, glued and taped together they were glued to a flat piece that would eventually become the raised "brick" base.

You can see that the connecting edge between the columns and the base was less than appealing, so it needed to be prettied up a bit


When working with cardboard for structural work like this, be mindful of the way in which the cardboard grain is situated. Those little faint lines on the outside of the cardboard that show how the wavy part in the middle is arranged. Generally, it is best to try and work so that you cut and fold with the grain, not against it. Plus, the grain direction can help add additional strength to your structures

*** END NOTE****

Step 3: Covering the Column-base Joint

After taking some measurements I took one of the many scrap pieces of cardboard and made a wrap around base for the columns that would serve two purposes:

1) It coverd the cap

2) It added additional rigidity to the columns

Here you might want to use those weights, or some cardboard scraps...whatever, to hold these pieces in place while they dry. Or you could just sit there and have a deep conversation, watch a movie or hum softly to yourself for a good 15-20 minutes until the glue is dry enough to release...

Step 4: Putting on the Mantel

I found this nice large lid from an electronics shipping box from work, it was just about the right size too!

Juuuuusssst a bit to wide for the over hang.... So, time to chop and re-size.

I took the industrial staples out of the longer front sides and cut off about 3 inches along the length of the lid.

Flipping the lid over, I placed the columns inside and the now-cut side of the box lid flush with the back of the columns.

At this point, the basic shape is coming together, finally something resembling a fireplace. From here, I started doing some reinforcing and "solidifying" of the mantel.

Step 5: Make the Mantel "solid"

To more easily access the underside of the mantel, I laid the structure on it's back. Using scraps of two-ply cardboard I cut and glued a basic framework, seen in the picture, to add strength and support so the mantel could hold some weight and not buckle.

In order to get this glued in, I placed a bead of a glue along each edge of frame. The weights are there to ensure that the parts are pressed firmly together until the glue dries completely.

To added a bit more support to the middle section of the mantel, add a cross brace between the two columns.

Once those pieces are good and solid, take a piece or two to cover this bracing and complete the "solid" look. I used two since at this point there were was not a single good piece of cardboard long enough to cover it.

As you can see, I fancied it up a bit by making some sconce-like supports. Not only did this add to the aesthetics, but it also created an added layer of strength.

The sides of sconces are cut out of two-ply board, whereas the single strip that encloses it is single ply. Using a bead of glue along the edges of the sides, carefully place, hold and fold the single-ply strip along the edge, as seen in the picture. Go slow with this part, be patient and let the glue dry thoroughly before proceeding to the next bend or fold.

When each of the two sconces are made, place and glue them on the underside of the mantel, each centered against a column, as shown. It helps to set the fireplace upside down for this.

With that done, lets move on to the base...

Step 6: All About That Base...

Now for the all important base. Since we have a very rambunctious 3 year old, we needed a good sturdy foundation; because at some point it was going to get sat on, jumped on, something...

In a cardboard recycle bin at work I came across an empty banded set of boxes with some extremely sturdy looking cardboard corners that would work great for this part!

Flip the fireplace over onto the mantel.

You can see the idea taking shape in the second picture. Basically, it's like building a deck. Since there were only four beam pieces to work with, and they were not quite long enough to span the entire length, they needed to be placed strategically in order to get the most efficient use out of them.

They were glued along one side, with scraps of cardboard placed in the center to make the bottom flush. Using whatever heavy and conveniently sized objects you have laying around, weight these down! Very important.

Once this is done, find a good, flat piece of cardboard that is at least the size of the top part of the base. It helps to measure and cut this ahead of time so it is ready go. I, however, failed in this regard and had to do this after the fact. Turned out okay, but with on-hand c'board running low, I was kind of regretting not doing this first.

Once the supports are dry, run a bead of glue across the top(bottom?) edge of each "beam"...

...Place the underside of the stand on the floor...

...Carefully turn the fireplace over and set on the underside piece of cardboard.

I did it this way because adding weight to it while upside would have risked toppling it over or warping the entire base. With the fireplace right-side up, on a level surface, it allowed me to see how level the whole thing was and to weigh down the base while it dried to ensure everything was put together properly while I still had time to make corrections.

You will now see that there is a gap around the base, between the top and bottom pieces. Too easy! Fill it with cardboard! Using strips of two ply, cut to length and height, simply put beads of glue along the top and bottom of the strips and wedge into place!

Step 7: Backing, Bricking and Painting.

Add a back, any back. Just a simple, single piece of cardboard spanning the back between the two columns, glue to the back edge of the mantel and the back of the base as well so it won't bow out.

To get a good brick effect, complete with the slightly 3D raised relief effect...more Cardboard!

Once I decided on an appropriate size of "brick", I set about finding as many single-ply scraps as I could find (had to go digging for another box to dismember).

Using a pattern, I traced out dozens of "bricks" on the cardboard, more than I what I needed, but that's okay.

Cut those bricks out!

Make sure that you have your bricks cut so that the grain runs perpendicular to the length of the brick, as you will be folding these around corners.

Starting at the bottom of one column, place/glue the 'bricks' in an alternating pattern as shown in the picture, leaving about a 1/4" gap between. Continue around each column. I was going to brick the back wall as well, but seeing as how it was going to be painted black, doing just a few to give the impression of a bricked back wall worked out great!

For the base I went with a smaller size brick...why? Meh... why not?

The painting was done by my wife, and I think she did a fantastic job! I came home from work and this just about blew me away! Brown for the mantel and sconce supports, because they are "wood", red for the bricks and grey for the "mortar" gaps. She even did a roughed up/burned effect with black and red for the inside!

Once the paint is dry, like really dry...not tacky at all, start decorating!

Now, Santa Clause has fireplace through which he can deliver his goodies on Christmas night!