Stone veneer (manufactured or natural) on a fireplace creates a stone-clad look without the weight of full masonry. Modern stone veneers are 1-1.5 inches thick, weigh 8-12 lbs/sq ft, and adhere to substrates with mortar. The work is essentially masonry: applying mortar bed, embedding stones, finishing joints.
This guide covers installing manufactured stone veneer on a fireplace surround over cement board or existing brick.
- Skill level
- Advanced
- Time
- 1-2 days
- Steps
- 11
- Tools
- 7, listed below
- Materials
- 7, listed below
Before you start
Three things to settle:
1. Manufactured vs natural stone. Manufactured (cultured stone): lighter (8-12 lbs/sq ft), consistent color and shape, less expensive. Natural stone: heavier (15-25 lbs/sq ft), unique appearance, more expensive. Manufactured for DIY; natural for premium projects.
2. Substrate preparation. Stone veneer adheres to: cement board, exterior plywood with weather-resistant barrier, or existing brick. Drywall not suitable — stone weight pulls drywall off. Verify substrate before starting.
3. Mortar joint style. Tight-fit (no joints visible): premium look, requires careful stone selection. Grouted joints: traditional look, easier to install, slight buffer for irregularities. Match style to design intent.
What you'll need
Tools
- Trowel (mason's, 4-6 inch)
- Margin trowel (small)
- Mixing paddle and bucket
- Wet saw or angle grinder (for cutting stones)
- Level
- Tape measure
- Pointing trowel (for joint finishing)
Materials
- Manufactured or natural stone veneer (sized to surround)
- Type S mortar (or stone-veneer-specific mortar)
- Bonding agent (Type N or stone-veneer adhesive)
- Metal lath (if substrate is exterior plywood)
- Cement board (if needed for substrate)
- Pointing tool
- Joint sealant (heat-rated near firebox)
Heat-rated mortar near firebox
Within 6 inches of firebox opening: heat-rated mortar (rated for fireplace).
Beyond 6 inches: standard Type S mortar acceptable.
Verify product specs.
Step-by-step instructions
Prepare substrate
Cement board: solid foundation; tape joints with mesh tape.
Brick: clean, no loose mortar.
Exterior plywood: install metal lath over plywood; lath provides bonding surface.
Verify substrate is solid before proceeding.
Plan stone layout
Mix stones from multiple boxes — avoid all dark or all light pieces in one area.
Plan corner stones at outside corners (some products have specific corner stones; others use rectangular stones with mitred corners).
Sketch placement; identify where to cut stones.
Mix mortar
Type S or stone-veneer-specific mortar.
Mix to creamy consistency (not too dry, not soupy).
Heat-rated mortar near firebox.
Mix only what you can use in 30-45 min.
Apply mortar bed to substrate
Trowel mortar onto substrate, 1/2 to 3/4 inch thick.
Apply only enough for next 2-3 stones (mortar dries quickly).
Substrate should be visible behind mortar; mortar isn't a structural layer.
Apply mortar to back of stone
'Buttering' the stone: mortar on back of each stone.
Not just on substrate — both for full bond.
Helps wet bond; ensures stone is well-adhered.
Press stone into mortar
Press stone firmly against mortar bed.
Wiggle slightly to set into mortar.
Verify stone is flush with adjacent stones (or per design).
Cut stones to fit
Wet saw with diamond blade for clean cuts.
Angle grinder for shaping.
Cut at edges and around firebox opening.
Test fit before applying mortar.
Continue stone placement
Build up rows of stones.
Stagger joints between rows (don't align vertical joints).
Variety of stone sizes prevents a 'gridded' look.
Allow some randomness.
Tool the joints
Wait until mortar is firm but not fully set (15-30 min).
Use pointing tool to recess mortar into joints (concave joint).
Or: leave mortar flush (modern look).
Or: tight-fit (no visible mortar) per design.
Brush off excess mortar
When mortar is firm: brush stone faces with stiff brush.
Removes excess mortar from stone surfaces.
Don't smear — work carefully.
Seal stones (optional)
Stone sealer protects against soot and stains from fireplace.
Apply per manufacturer instructions.
Re-seal every 2-5 years near active firebox.
Common mistakes that cost you
- Drywall substrate. Stone weight pulls drywall off wall. Cement board minimum.
- Skipping back-buttering stones. Insufficient bond. Always butter back of stone.
- Aligned vertical joints. Looks gridded, unnatural. Stagger like brick.
- All same-size stones. Rigid, unnatural look. Mix sizes for natural appearance.
- Standard mortar near firebox. Cracks from heat. Heat-rated mortar within 6 inches.
Frequently asked questions
Can I install stone veneer over existing brick?
Yes — brick provides solid substrate.
Clean brick of any loose mortar before applying.
Apply mortar bond and stones directly over brick.
What's the difference between manufactured and natural stone?
Manufactured: concrete cast in molds to look like stone. Light, consistent, less expensive.
Natural: cut from quarried stone. Heavy, unique, more expensive.
For DIY: manufactured is the typical choice.
What drives the cost of stone veneer?
Material choice is the main driver: manufactured stone veneer is lighter and more economical, while natural stone veneer costs more and weighs more.
Wall area, plus mortar, lath, and sealant, adds to materials.
Labour complexity depends on wall height, pattern, and how much cutting and fitting the stone requires. We provide a detailed written breakdown before work begins.
Can stone veneer be installed over drywall on a fireplace?
No. Stone veneer should not go over drywall, because the weight of the stone pulls drywall off the wall. Manufactured stone weighs 8 to 12 lbs per sq ft and natural stone 15 to 25 lbs per sq ft. Suitable substrates are cement board with taped joints, clean existing brick with no loose mortar, or exterior plywood covered with metal lath to give the mortar a bonding surface.
Cement board is the minimum.
What mortar should be used for stone veneer near the firebox?
Heat-rated mortar, rated for fireplace use, belongs within 6 inches of the firebox opening. Beyond 6 inches, standard Type S mortar or a stone-veneer-specific mortar is acceptable. Standard mortar close to the firebox cracks from the heat. Mix only what can be used in 30 to 45 minutes, to a creamy consistency, and use a heat-rated joint sealant near the firebox too. Check the product specs before buying.
When to call us instead
Stone fireplaces are signature features in living rooms. Our team handles design, masonry, and install.
Book a free 60-minute site visit →Dream Touch Renovations · 33 Roydon Pl, Suite 210, Ottawa, ON K2E 1A3 · (613) 862-4555
Renovating homes across Ottawa, Kanata, Nepean, Barrhaven, Orléans and Stittsville.
Related Ottawa services
If your living room renovation includes a stone fireplace, our team handles the full scope. Book a free 60-minute consultation.
Official references
- Do I need a building permit?, City of Ottawa
- O. Reg. 163/24: Building Code, Government of Ontario