Faux Concrete Fireplace Surround and Mantel

How To: Fire & Stone – The Muddy, Messy Road to Cozy Warmth


Our basement was a perfectly serviceable rumpus room. Yes, it’s where the “Wild Things” hung out. Well, that was until 3 years ago when I stumbled onto a beautiful antique pool table at a neighbor’s. Thwarted by the basement stairwells, it ended up in their garage sale. Fortunately, our basement is a walkout. And I couldn’t walk out of their garage without naively claiming that table as ours.

Thus began the 3 year DIY project. Yes, the pool table is significantly larger than the Air Hockey table it replaced. So game area flips with lounge area, which means we steal a bit of space from the adjoining storage room; and certainly that pool table couldn’t sit on the painted concrete floors and certainly new carpet deserves fresh paint, which of course means … and on … and on … Oh yeah, like you‘ve never brought home a pair of shoes that demanded a whole new outfit. Yeah, I thought so.

And now,  finally, the biggest ticket element is in the final stages. Yes, the gas fireplace we’ve been dreaming of and saving for is ordered. Now what to do for the surround and mantel? We wanted a solid, built-in, warm look but with no busy texture. fall-mantel-1

Once I saw this photo of a cast concrete fireplace surround on Nell Hill’s website, I knew what we had to have. But I didn’t want to wait 3 more years while we saved up the serious dough that a custom concrete surround requires.

So, being the thrifty DIY-er,  I broke out some trusty supplies and started experimenting. The result: A custom “concrete” fireplace surround, mantel and flue for less than $125 in supplies. (Check out the supply list at the end of this post).

Can you see it yet? The construction is done.

Yes, the fire box is not centered in the surround. Blame those pesky support beams. No point in rehabbing the basement to have the top two floors coming crashing down, right?

It will work once I get to accessorizing, trust me.

Now let the fun begin. Mud pies and Finger Paints, anyone?


Just a bit of detail on the construction decisions:

I rescued a great mantel from the ReStore to use. But, Safety codes + raised hearth + low-hanging beam = mantel profile NOT mantel overhang. Pooh! So mantel was set back for no overhang.

We finished the frame surrounding the firebox with bullnose edging to marry up with the profile of the mantel.

Not the original vision, but I’m still lovin’.


Sand the gloss and filler off the mantel.


Tape off the walls and lay on a good coat of primer.

I used some leftover Kilz I had on hand as really the idea is to unify the color of the wood part with the drywall part, so the final product is cohesive.

Once the primer is dry it’s time to layer on the “concrete”, kinda like frosting a cake. But my icing is joint compound.


The joint compound needs to be thinned a bit, but rather than water, I used latex paint. This thins it while also altering the color to a version of concrete that works for our room.

Bonus: two steps in one – color and texture. Woo!Hoo! Streamlining!

Yes, I just raided my paint stash and started adding anything latex I thought would take it from the cold grey of joint compound to a bit brighter and warmer beige/grey concrete.


This took a bit of experimenting. So I used a piece of white cardboard, close to my basecoat primer starting point. Initially a bit too yellow, then pink undertone – ooow, not good! – then finally had it right.

Yes, the colors in the pic are all off, but you get the idea.

The color changes significantly from wet to dry, so be sure you let it dry before judgement.


I started by trying to spread my mud mixture with a putty knife. Don’t recommend this.

Rather, I found a wide foam brush worked the best. Surprisingly, it held up great with the weight of the mud.


But then when you get to the dips, valleys and curves, nothing works better than your fingers. Aww, how I miss those kindergarten days.

As with painting, the best results are from two light coats, rather than one heavy coat.


After the initial layer of mud is on, let it dry a bit and then smooth it out using a combination of this damp tile sponge and foam brush.

Then in selected spots, a light pouncing of the sponge produces the “concrete” dimples I was hoping for.


In those tight spaces and valleys, I again resorted to my fingers. Here I dipped my fingers to get them plenty wet, so the mud wouldn’t stick to them as the idea now is to smooth and texture the mud that is already in place.

(Yikes! time to schedule a deep conditioning manicure)


And on the flat surfaces where I used a sponge to create the dimples, if it left some raised bumps, or too much texture, I again used my wet fingers to smooth them out a bit.

I was going for the look of traditional cast concrete, not adobe or stucco. If those fits your home and style, then certainly adjust your texturing accordingly.

After the initial coating is completely dry, lightly sand, wipe away the dust and layer on a second coat using the same method.

Again, dry, sand and wipe.


Joint Compound is porous – yes, it will absorb any splatter of pizza sauce, spray of Dr. Pepper, or splash of red wine, not that any of that would happen in our house. It’s also dusty, chalky.

Two coats of Dead Flat Varnish from Modern Masters, a sister company of Rustoleum, is protecting our new basement focal point from all of “Life’s Fun”.

It is the only water-based, truly flat finish varnish I know of. It is a bit pricey at $31, but I have a number of projects I plan to use it on. And it was perfect here.


Fireplace is installed – by the Pros! I’m off for that deep conditioning manicure, then back to let the decorating begin!

This is the view as you come down the stairs. Love the impact of my great sunburst clock there – a real Wow factor from that angle. But from the rest of the room, it’s chopped off too much by the low-hanging beam. So it will hang in a better, more deserving spot in this new room.


For now, I’m going with this as my initial set-up. Certainly it will change significantly with the seasons and my whims – and of course as I score new treasures and flex my crafting muscle.


The fireplace is a huge one off the list, but still many details to go:


First, tile that hearth bench! And surely, the back-ordered steel fireplace frame will arrive soon. Multiple swoon-worthy throw pillows, of course! Window treatments, drawer pulls and cabinet knobs, switchplate covers, magazine & book rack, drum shade over the game table, …. And yes, the sons’ top priority, a B.I.G. flatscreen TV – someday, boys, someday!

For you skeptics, my promised supply list:

Oak mantel: $20

Drywall, tape, bullnose: $20

Screws & Nails: $18

Joint Compound: $13

Lumber: $22

Dead Flat Varnish: $31

Total: $124

Don’t hesitate to contact me with any questions. I’m happy to lend advise and encouragement should you head down a similar muddy road. Don’t be intimidated – it’s really very fun and easy. (Not so much the construction, mind you).

2 Responses to “Faux Concrete Fireplace Surround and Mantel”

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  1. Kristen says:

    Beautiful! What is inside the fireplace? It looks like real fire!

    • admin says:

      Thanks Kristen! That is a real fire. It’s a vent-free gas fireplace. That’s the reason I couldn’t have the mantel profile extend out in front like originally planned.

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