MDF or Plywood for fireplace mantel and surround

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Forum topic by kent_michaels posted 03-16-2011 04:40 PM 28713 views 0 times favorited 17 replies Add to Favorites Watch
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34 posts in 2869 days

03-16-2011 04:40 PM

Topic tags/keywords: question

I already have a design in mind for a fireplace mantel and surround but I’m not sure which material is best to use around a fireplace. i’d really appreciate any advice on this from more experienced wood workers. Thanks for any help.

17 replies so far

View Bertha's profile


13551 posts in 2871 days

#1 posted 03-16-2011 04:42 PM

Ply for me for sure. I’m not a homebuilder, so I’ll defer to the experts below. Good luck!

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View Bill White's profile

Bill White

5108 posts in 4138 days

#2 posted 03-17-2011 12:40 AM

Just finished building my second surround from MDF. Have had no problems with either construction or heat from the FP. Would do it again. Both were paint grade, so finish was not an issue. Primed ‘em with shellac to seal before the paint.


View Luke's profile


290 posts in 2865 days

#3 posted 03-19-2011 12:28 AM

I just did my fireplace with Frame and Panel Wainscoting and Mantel, I used Ply because I HATE MDF, but in hindsight, MDF might have given a more consistent coat of paint being that Plywood has some inconsistencies in texture. (Yes i did use Cabinet Grade Plywood)

So my next adventure for Wainscoting will probably be with MDF.

View drewnahant's profile


222 posts in 3267 days

#4 posted 03-19-2011 12:37 AM

if it is going to be painted, I’d go with MDF. as much as I dislike the stuff, if yuou want to go with a sheet product, mdf will allow you to construct without hiding endgrain on the corners, it mills up beautifully with saws and router bits, and it paints evenly. It does not do well with moisture, but stands up to heat very well. one caution, make clean cuts and router well, because it does not sand nearly as well as it mills, you end up with a fuzzy surface, the only solution I have found for this which works really well is to coat with thinned epoxy or shellac, depending on the finish applied over it, let that harden the surface, then sand it again.

plywood is stronger, more moisture resistant, and gives you a grain texture on the surface, but it is more expensive, has nasty edges, even if you get good stuff without any voids, and if you plan on doing any shaping, you will have to paint it many times to cover the alternating grain in those edges. that being said, you could always attatch solid edging to any areas you plan to shape or router, but that’s just more work

View Jonathan's profile


2609 posts in 3228 days

#5 posted 03-19-2011 04:00 AM

I’m assuming you’re going to paint this since you mentioned MDF here? Or are you considering MDF/ply for the core, with veneers over the top, then putting a finish over that?

I am still trying to get together my mantel/fireplace surround and built-in bookcases. Hopefully it’ll happen sometime in the next couple of months. I’m going the plywood route, but that’s because I plan on staining everything, as I want to use oak for the grainy look. With that being said, if I were going to have it all painted, I’d go MDF.

-- Jonathan, Denver, CO "Constructive criticism is welcome and valued as it gives me new perspectives and helps me to advance as a woodworker."

View Torr's profile


20 posts in 2824 days

#6 posted 03-19-2011 04:56 AM

I used MDF for the legs and facing, but ply for the mantel shelf, using the theory the shelf would get more wear and tear. The legs were 3-sided boxes with lock miters, nailed from the sides into cleats mounted to the wall. The shelf and facing were similar, then trimmed with molding and painted. Surround and hearth were tiled first, then mantel built in place. Here is the result….

P.S. The manual for my gas fireplace had clearly defined clearances to combustibles including the allowable projection of the shelf at varying heights. You’d behoove yourself to check this for your application. For wood burning fireplaces I believe this is addressed in the various building codes. I definitely noticed the shelf getting warm when the blower was not turned on when the fireplace was running. I personally would absolutely respect any clearance requirements….


View wood4me's profile


5 posts in 3971 days

#7 posted 03-21-2011 01:06 AM

Mdf is perfect for projects which will be painted, and where moisture will not be a problem.

I love the look of woodgrain, and for that reason choose to build mine from Tasmanian Oak.

-- wood4me

View Gillie's profile


1 post in 1841 days

#8 posted 11-06-2013 03:16 AM

Hi Torr, I don’t suppose you would share your plans for your mantel piece.

View Loren's profile


10477 posts in 3826 days

#9 posted 11-06-2013 04:27 AM

Paint the edges of ply and the plies telegraph through, so for
paint grade work that goes around corners, MDF is simpler
to work with because butt joints can be managed and
roundovers turn out nicely too.

View Moron's profile


5032 posts in 4071 days

#10 posted 11-06-2013 04:45 AM


-- "Good artists borrow, great artists steal”…..Picasso

View waho6o9's profile


8491 posts in 2755 days

#11 posted 11-06-2013 04:50 AM

MDO paints better


View Moron's profile


5032 posts in 4071 days

#12 posted 11-06-2013 04:52 AM

only an idiot would argue the merits of a budget

some moron thinks if it aint wood, it aint good

fools are born everyday

-- "Good artists borrow, great artists steal”…..Picasso

View realcowtown_eric's profile


617 posts in 2115 days

#13 posted 11-06-2013 05:01 AM

MDF or Ply, pretty much the same.

Except that the heat from the fireplace can more likely alter the colour of the finish on MDF than it would with ply and solid mouldings. But over time. White lacquer on MDF will eventually take on a yellowish colour shift.

Building codes specify projection of mantels etc typically in a general sense, but oftentimes incorporate phrases such as “compliance with manufacturers specifications” taking precedence. For inspection, better have a copy of the destructions handy. MFGRS specs are more specific …x inch projection at y height above fire box opeing. Generally I follow mfgrs guidelines as they have the underwriters/CSA certification, and local codes USUALLY say that mfgrs specs override the local codes. Usually.

I use metal studs for my fireplace surrounds, cement board for any tile, Love planished copper panels over cement board, held in place with ceramic magnets.

Ever look at tile surrounds and wonder how much destruction would be involved with gaining access to the fire box should problems arise?

Recently had discussion with fireplace installerSSS over size of hearth 2’ below the firebox. They all repeated the dogma 18”. I said otherwise, and when they eventually read the code pages at hand, they all finally agreed that it had to be 24”ish. Me I’m a cabinet maker, they install fireplaces, and didn’t have the cognition to apply the code. Gottta love it.

Client was looking at back-lit onyx (looks fantastic), but it’s not non-cpmbustible due to the backing and the LED panels, so it couldn’t cover the firebox to floor area.

Oh, but the installer was all to keen to install it at a premium price too!. Makes you wonder what non-code compliant installations are out there. and done by reputable companies….

Me I don’t play with fire, particularly in my clients homes.

Fires happen from time to time, I just don’t ever want to be responsible for that happening to any of my clients.

Check fireplace mfgrs specs, check local codes, maybe even talk to yer insurance agent too!

It ain’t rocket science, but you have to do yer due dilignence.

Eric in Calgary

-- Real_cowtown_eric

View MrRon's profile


5150 posts in 3421 days

#14 posted 11-06-2013 04:43 PM

Whats wrong with using 1x and 2x solid wood? Boards come inn widths up to 11-1/4”. You can even get wider boards that have been glued up from narrower boards. Solid wood is much easier to work with with much less waste and no ply edges to deal with. Pine boards take paint better than ply or MDF.

View Torr's profile


20 posts in 2824 days

#15 posted 11-09-2013 02:41 PM


Sorry, but I don’t have any plans. I basically designed it on the fly to fit the fireplace.


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