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How to Clad Concrete Steps in Stone

Overhaul your boring concrete porch with bluestone and natural-stone veneers

Though you may wish you could take a sledgehammer to those drab concrete steps tarnishing your home's curb appeal, we have a better plan. Veneer them in handsome stone to turn your embarrassing entry into a welcoming focal point. This Old House senior technical editor Mark Powers will tell you it takes at least one strong buddy to place the bluestone tread caps and that you should check your local codes about riser heights. He'll also show you the simplest way to tackle this value-boosting project.

Granite veneer: New England Thinstones' Chesterfield Square & Rectangle, about $12.50 per square foot, and corner stones, about $15 per linear foot; New England Thinstones. Treads: 1½-inch thermally treated bluestone, about $13 per linear foot; Fairfield Stone and Landscape Supply. Landing pavers: 1-inch thermally treated bluestone, about $7.25 per square foot; Fairfield Stone and Landscape Supply. Mortar: Quikrete Veneer Stone Mortar, about $5 for an 80-pound bag; QUIKRETE

Step 1

Overview Cross Section of Concrete Clad Steps

Illustration by Gregory Nemec

Day-to-day timeline

FRIDAY Prep the wall and steps (Steps 2-5).

SATURDAY Install and grout the veneer stones (Steps 6-13).

SUNDAY Set the bluestone treads (Step 14-16).

HOOKY DAY* Install and grout the landing pavers (Step 17-19).

* Extra day needed to allow the mortar drying time between steps

Step 2

Remove the Threshold Riser

Photo by Kolin Smith

Any trim board beneath the door must be removed and cut to allow the new pavers to slip beneath it. Use a utility knife to score around the board, then work it loose with a pry bar. Pull out the board's nails, and set the board aside to be scribed, trimmed, and reinstalled later.

Step 3

Trim the Shingles

Photo by Kolin Smith

Likewise, shingles around the landing must be trimmed to allow for the stone. Measure the thickness of the pavers and stones, add a little space for mortar, and use a board to scribe the shingles. Cut them using several passes with a utility knife.

Step 4

Install the Lath

Photo by Kolin Smith

For the mortar to grab, you must either scarify the concrete with a grinder or add a scratch coat, like we did. First, lay lath over the landing and steps, and use tin snips to trim sections for the sides that overlap the steps by 2 inches. Before cutting it, make sure the lath is oriented correctly: with the cheese-grater-like "cups" facing up so that the scales feel rough as you run your hand away from the door and down the side. Use a powder-actuated nailer and a hammer to nail down the lath every 6 to 8 inches.

Step 5

Add the Scratch Coat

Photo by Kolin Smith

Mix mortar to the consistency of warm, creamy peanut butter, and use a finishing trowel to apply it to the lath. Pull the mortar downward to fill the cups, then work in a fanning motion to create a ½-inch-thick layer. Now use the notched side of the trowel to comb the mortar horizontally, creating grooves. Allow the scratch coat to dry at least overnight—24 hours is best.

Tip: To divert water from the house, run self-adhesive flashing from the lip of the threshold down onto the landing. At the sides, tuck it under the shingles by several inches.

Step 6

Fit the Stones

Photo by Kolin Smith

Dry-fit stones against the risers with an L-shaped corner stone at each end; leave a finger's-width gap between them for mortar. Group the riser stones and set them aside. Measure the side profile of the steps, and use painter's tape to outline it on a canvas drop cloth. Start with the L-shaped corner blocks from the risers, then arrange the larger stones a finger's width apart, with staggered joints.

Step 7

Score the Cutlines

Photo by Kolin Smith

Mark cutlines on the back of the stones. Using a grinder fitted with a diamond masonry blade, score the line halfway through the thickness of each stone.

Step 8

Break the Stones

Photo by Kolin Smith

Place a mason's chisel in the score line at one end, angled slightly toward the waste side. Strike the chisel with a maul to break the stone cleanly. Use a brick hammer to chip off any excess. Working on a soft surface, like grass, will help evenly support the rough face of the stone and reduce the chance of cracking.

Step 9

Apply Mortar

Photo by Kolin Smith

Get started by using a chip brush to apply a thin coat of acrylic bonding agent to the installation area to give it extra grab. Then mix mortar to the consistency of warm, creamy peanut butter. Using a brick trowel, apply a ½- to ¾-inch layer to the back of a corner stone on the first riser, leaving a bit extra in the corner. Use the tip of the trowel to create a horizontal furrow on the buttered side that will help lock the stone in place.

Step 10

Clad the First Riser

Photo by Kolin Smith

Press the stone into place, wiggling it in tight to create a vacuum behind it. Each riser veneer should be flush with the top of a stair. Be quick with your trowel to keep oozing mortar from staining the stone's face. Once the stone is set, leave it alone; disrupting it could break the vacuum, forcing you to start over. Working from left to right, install the riser stones with their faces relatively flush, using a thicker layer of mortar for thinner stones.

Step 11

Clad the Sides

Photo by Kolin Smith

Follow the same procedure to install the stones that are in line with the riser on the sides of the landing. Then install the corner stones on the second riser, and so on. Allow some time between levels. You can use small chunks of waste between the stones to keep their spacing; just remember to remove them before the mortar sets.

Step 12

Grout the Stones

Photo by Kolin Smith

Fill the grout lines. Clear out any loose chunks of mortar. Mix the mortar to the consistency of pudding. Fill a grout bag halfway, and twist the open end like a bread sack to release air bubbles and force mortar out the tip. Now hold the tip between the joints and squeeze mortar into them. Work from bottom to top, drawing the bag upward through the vertical joints and then pulling it across the horizontal joints to fill them.

Step 13

Strike the Grout Lines

Photo by Kolin Smith

Allow the grout to cure until pressing it with a finger leaves a dent but doesn't break through the surface. Now use a striking tool to shape the grout.

Step 14

Lay the Mortar Bed

Photo by Kolin Smith

First, mark the center of each tread and the center of each riser with a piece of painter's tape. Mix mortar until it's thick enough to hold its shape when balled up, and trowel it onto the first step in a ¾-inch layer. Using a 4-foot level to check your work, create a mortar bed that's level side to side, with a light taper toward the front lip.

Step 15

Add a Slurry Mix

Photo by Kolin Smith

Make X's in the mortar bed with the trowel's edge, and pour a soupy mortar mix onto it to allow for tread adjustment.

Step 16

Set the Tread

Photo by Kolin Smith

Use the tape to center the first tread, and set it in place, flamed edge outward. Check for an equal overhang on the sides and for level side to side. You want a very slight slope toward the front, to shed water, but no more than 1/16 inch per foot. Working out from the center, strike the tread with a rubber mallet to set the stone. Set the remaining treads, maintaining a uniform front overhang and height above the previous tread. Check your local codes for stair heights, and to keep people from tripping, make sure the height of each riser is within 3/8 inch of the others.

Step 17

Install the Perimeter Treads

Photo by Kolin Smith

Follow Steps 14 and 15 to create a mortar bed on the landing, and place the perimeter treads with the flamed edges exposed and overhanging evenly. Use a straightedge to make sure the overhang matches that of the top stair tread. Use a rubber mallet to set the perimeter treads flush with the back edge of the top stair tread, maintaining the 1/16-inch-per-foot pitch all the way back to the house. Allow the treads to set overnight.

Step 18

Add the Interior Pavers

Photo by Kolin Smith

Build up mortar beds and install the interior pavers the same way. Keep them flush with the surrounding treads, following the water-shedding pitch, and leave uniform grout lines.

Step 19

Grout the Joints

Photo by Kolin Smith

Carefully fill the grout lines with mortar and use the striking tool to shape a clean, curved seam just below the surface of the stones. Finish by scribing and cutting the below-door trim to leave a ¼-inch gap beneath it, and reinstalling it.