Cast stone fireplace install guide.
Step-by-step for the one-piece cast stone surround, the three-piece cast stone mantel, and the wall-hung mantel shelf. Pick the guide that matches your crate.
Install the one-piece surround.
Newport, Verona, and similar one-piece units ship as a single cast that wraps the firebox. A single long ledger across the back carries the weight; the cast stone screws into it from behind.
Place the hearth
If you have a hearth, dry-fit it first. Lay a continuous bead of construction adhesive on the subfloor where the slab will sit. Set the slab, check level, shim from below if the floor reads off. Wipe any squeeze-out immediately with a damp rag.
Anchor the hearth
If the hearth is thicker than 1", drive 4" wood screws through the back edge into the wall stud (discreet, not visible). For 1" hearths, construction adhesive alone is sufficient. For two-piece miter hearths (60"+ lengths), fill the miter joint with color-matched caulk before moving on.
Align the filler panels
Filler panels (the narrow trim between the firebox opening and the surround) come in the crate. Dry-fit them first. Mark anchor points on the outer edge of each panel, never the face. Once the surround is set, its face covers those holes.
Mount the filler panels
Pre-drill the marked points on each panel. Anchor to the wall through the outer edge using sheetrock anchors (drywall) or wood screws into a stud (preferred). Confirm plumb against the wall before moving on; the surround will reference off these.
Mount the back-top ledger
Locate the studs across the width of the surround and mark a level horizontal line where the back-top edge of the unit will sit. Cut a 2x4 that catches at least two studs and screw it flat to the wall along the marked line with 4" wood screws, into stud, never drywall alone. The ledger carries the weight.
Take your time on this line: if the ledger is level, everything after it lines up. Check it once more before the last screw.Set the surround
Lay a soft-cloth blanket on the floor and uncrate the unit. Three installers minimum on Verona / Newport sizing; two on smaller models. Apply construction adhesive in an "S" pattern across the back face (corners and centerline), leaving 1" gaps for ventilation. Walk the surround up to the wall, set it onto the hearth (or against the wall if no hearth), and slide the back-top against the ledger. Check sight-lines with a 4ft level across the top. The reveal between the firebox opening and the inside edge of the surround should read 1/2" to 1" depending on model.
Secure from the back
Drive 4" wood screws diagonally through the back of the surround into the ledger, typically four to six screws across the width. The pre-cast pockets on the back face are sized for this; never drill into the visible front face. Tighten snug, not crushing. Over-torque hairlines the cast stone. Once the screws are set, work the concrete stain from the finish kit over each screw spot (two thin coats, 30 minutes between) until the spot disappears into the surrounding finish.
If anything looks off, stop and call us at (971) 314-9530 before you caulk. It’s easy to adjust now; once the caulk and stain set, the fix can mean casting a new piece.Caulk every seam
Where the surround meets the wall, the filler panel, and the hearth, fill each joint with the color-matched sanded caulk that ships with every order. Tool with a fingertip and a damp sponge to leave a hairline shadow, not a bead. For lighter colors, mask the surrounding face with painter's tape before tooling.
Install the three-piece mantel.
Hearth, two legs, mantel. Each piece anchors to its own hidden 2x4 ledger behind it; cast stone never carries its own weight on a screw. Order matters: hearth first, mantel last.
Place the hearth
If you have a hearth, dry-fit it first. Lay a continuous bead of construction adhesive on the subfloor where the slab will sit. Set the slab, check level, shim from below if the floor reads off. Wipe any squeeze-out immediately with a damp rag.
Anchor the hearth
If the hearth is thicker than 1", drive 4" wood screws through the back edge into the wall stud (discreet, not visible). For 1" hearths, construction adhesive alone is sufficient. For two-piece miter hearths (60"+ lengths), fill the miter joint with color-matched caulk before moving on.
Align the filler panels
Filler panels (the narrow trim between the firebox opening and the legs) come in the crate. Dry-fit them first. Mark anchor points on the outer edge of each panel, never the face. Once the leg is set, the leg face covers those holes.
Mount the filler panels
Pre-drill the marked points on each panel. Anchor to the wall through the outer edge using sheetrock anchors (drywall) or wood screws into a stud (preferred). Confirm plumb against the wall before moving on; the legs will reference off these.
Set the leg ledgers
Cut two short 2x4s, one for each leg. Position each ledger 3/4" inside the outer edge of where the leg face will sit, vertical against the wall, plumb. Screw into the wall stud with 4" wood screws. The leg will hide the ledger completely once set.
Why 3/4" inside: Recessing the ledger leaves room for the leg face to read flush with the surrounding wall without the ledger pushing it forward.Set the legs
Lay a soft-cloth blanket on the floor and uncrate each leg. Apply construction adhesive in an "S" pattern across the back face (corners and centerline), leaving 1" gaps for ventilation. Walk each leg into position against its ledger and press into place. Drive screws diagonally through the back of the leg into the ledger; never drill into the leg face. Check sight-line alignment with a 4ft level across both legs. The reveal at the firebox opening should read 1/2" to 1" depending on model.
Mark the mantel ledger line
With the legs set, measure the mantel: width, depth, and the height of the back face that will contact the wall. Mark a level horizontal line where the back-top edge of the mantel will land. This is your ledger position.
Mount the mantel ledger
Cut one long 2x4 spanning the full width of the mantel and catching at least two studs. Screw it flat to the wall along the marked line with 4" wood screws into stud. Confirm level one more time: if the ledger is level, everything after it lines up.
Set and secure the mantel
Apply a 3/8" adhesive bead across the top of both legs and across the top edge of the ledger. With three installers, walk the mantel up and set it onto the legs, back face flush against the ledger. Drive 4" wood screws diagonally through the back of the mantel into the ledger, two to four screws depending on length. Tighten snug, not crushing. Once the screws are set, work the concrete stain from the finish kit over each screw spot (two thin coats, 30 minutes between) until the spot disappears into the surrounding finish.
If anything looks off, stop and call us at (971) 314-9530 before you caulk. It’s easy to adjust now; once the caulk and stain set, the fix can mean casting a new piece.Caulk every joint
Where leg meets mantel, where leg meets filler panel, and where leg meets hearth, fill each joint with the color-matched sanded caulk that ships with every order. Tool with a fingertip and a damp sponge to leave a hairline shadow. For lighter colors, mask the surrounding face with painter's tape before tooling.
Install the mantel shelf.
A single cast piece against a single horizontal ledger: no firebox surround, no legs. The hardest part is locating studs and getting the ledger level; the stone itself sets in minutes. See the three shelf profiles.
Mount the ledger 2x4
Locate the studs above the firebox and mark a level horizontal line where the back-top edge of the shelf will sit. Cut a 2x4 to a length that catches at least two studs and screw it flat to the wall with 4" wood screws, directly into the stud, not into drywall alone. The ledger carries the weight; the wall does not.
Drywall-only run: If you can't catch a stud, use 3/8" toggle bolts rated for the piece weight. A standard mantel shelf runs 80 to 180 lb depending on length.Set and secure the shelf
Lay a soft-cloth blanket on the floor and uncrate the shelf. Apply a 3/8" bead of construction adhesive across the top edge of the ledger. Walk the shelf up to the wall with two installers, slide its back face flush against the ledger, and press into place. Drive 4" wood screws diagonally through the back of the shelf into the ledger, two to four screws depending on length. Never drill into the visible front face. Once the shelf is set, work the concrete stain from the finish kit over each screw spot (two thin coats, 30 minutes between) until the spot disappears into the surrounding finish.
Caulk the seams
Where the shelf meets the wall, fill the joint with the color-matched sanded caulk that ships with every order. Tool with a fingertip and a damp sponge. The seam should read as a hairline shadow.
What you'll need on site.
The finish kit (concrete stain, concrete-mix powder, and color-matched caulk) ships with every order, and surround and mantel crates include the filler panels unless your design leaves them out. Framing lumber, anchors, and the adhesive are sourced locally.
Tools
- Screw gun All paths
- Caulk gun All paths
- 4ft level All paths
- Measuring tape All paths
- 3/16" masonry bit All paths
- 3/8" masonry bit All paths
- Appliance dolly Surround · Mantel
- Soft-cloth blanket All paths
- Damp sponge All paths
Materials
- ×1Long 2x4 ledger All paths
- ×2Short 2x4 leg ledgers Mantel only
- ×1Construction adhesive (PL Premium) All paths
- 4" wood screws All paths
- Sheetrock anchors Drywall runs
- ×1Finish kit (concrete stain, concrete-mix powder, color-matched caulk) All paths · ships with order
- Painter's tape Light colors
Need per-model install notes?
Every model has its own spec sheet with dimensions, estimated weights, finish options, and install notes. They download free from the spec library, no sign-up needed. For CAD blocks and 3D files, tell us the model and we’ll email them.
Stuck mid-install? Call us at (971) 314-9530, Monday to Friday, 8 a.m. to 4 p.m. Pacific. We answer the phone and can talk you through it.
Frequently asked questions.
Ten questions general contractors, architects, and homeowners ask before, during, and after install.
Which install guide do I follow?
Open your crate and count the major pieces. One cast piece wrapping the firebox is a Cast Stone Surround. Two legs plus a mantel is a Cast Stone Mantel. A single wall-hung piece is a Cast Stone Mantel Shelf. The shipping manifest in the crate lid confirms which.
Did my order include a hearth and filler panels?
Filler panels come in the crate with every surround and mantel order, unless your design leaves them out. A hearth is an optional add-on you choose with your order. The shipping manifest lists everything in the crate. Install them before the main piece: hearth before any vertical pieces, filler panels before the legs or surround.
How long does installation take?
A Cast Stone Surround installs in three to five hours with two to three installers. A Cast Stone Mantel installs in six to eight hours with the same crew. A Cast Stone Mantel Shelf installs in two to three hours with two installers.
How heavy are the pieces?
A mantel shelf runs 80 to 180 lb depending on length. Mantel legs and mantels run 80 to 220 lb each. Our spec sheets estimate a whole surround at about 150 to 470 lb, depending on the model and size; a one-piece Newport runs about 280 to 350 lb. One-piece surrounds go up as a single heavy unit, which is why three installers and an appliance dolly are essential for the Newport and Verona.
Can a homeowner install it themselves?
A mantel shelf is a good project for a handy homeowner with a second person to help. For a three-piece mantel or a one-piece surround, we recommend a general contractor, mason or finish carpenter: the pieces are heavier than they look, the ledger has to be set just right, and the finish kit needs to go on correctly the first time. Whoever installs it, we’re a phone call away at (971) 314-9530.
Why a 2x4 ledger instead of anchoring through the face?
Cast stone reads best with no visible hardware on its face. The ledger is a hidden wood backer, screwed into the wall studs, that the cast stone screws into from behind. It carries the weight, hides the fasteners, and lets us anchor into wood even on a drywall wall.
What if my install reveals a sizing issue?
Stop and call us at (971) 314-9530. Cast stone re-cuts on site are difficult and usually compromise the finish; a re-cast means another production run in our shop. We would rather catch a sizing issue at dry-fit than after the caulk and stain have set.
What's the lead time on replacements?
Standard production runs six weeks. Expedited three-week service is available at 35% above list (figured on list price, and it can’t be combined with the trade discount). For freight damage: if you can see damage at delivery, refuse the delivery or note the damage on the receipt, and send us photos within 24 hours. We handle the freight claim. Pieces damaged beyond repair are remade or replaced, and minor damage is repaired.
Do you provide on-site installation?
In-person installation is a paid concierge add-on anywhere from Eugene to Portland (including Vancouver, Washington) and from Bend to the Oregon coast. Outside that area, we coordinate with the homeowner's general contractor. Trade partners (architects, designers, custom-home builders) typically handle install through their own GC; we provide the finish kit, the install guide, and direct phone support throughout the install.
How do I clean the stone long-term?
A soft, dry cloth removes daily dust. For build-up around the firebox, use a soft cloth lightly dampened with warm water. Wring it almost dry before wiping. Never use abrasive cleaners, oven cleaner, bleach, or acidic cleaners. The finish protects against soot, but it is a finish, not armor. Treat it like fine furniture, not like tile.