The benefits of modern stone veneer
If the words “cultured stone” conjure
up images of a fake that you can
spot a mile away, then you need to take a
look at modern manufactured veneer
stone. Today’s versions look so good that
you’ll be hard-pressed to tell them from
actual stone. And since manufactured
stone is cheaper and lighter than the real
thing, it’s a great DIY choice for any stone
There are several national brands of
manufactured stone—including Eldorado,
Coronado and Cultured Stone—and they
all provide detailed installation instructions
on their Web sites. But we were sure that a
professional would have tons of great tips
and advice, so we enlisted Marcus Schilling,
a third-generation mason, to show us how
he installs it. And sure enough,
we were right.
You can use manufactured stone
indoors or out, but exterior applications
require special attention to details of
waterproofing and flashing. Before installing
exterior stone veneer, talk to your local
building inspector to see what’s required
in your area. We’ll show you tips for
installing it indoors;
however, most of the tips also apply to
Modern stone veneer installation
Stone Veneer in a Nutshell: Installation Basics
Before we launch into
the tips, it’s helpful
for you to have a general
idea of the installation
Almost all stone
start with a layer or
two of building paper,
covered by properly
installed dimpled and
galvanized wire lath.
The next step is to
cover the lath with a
1/2-in. layer of Type S
mortar, which is
“scratched” while it’s
still wet to allow the
stone to cling better.
After this “scratch
coat” dries overnight,
the stone is applied
with the same type of
mortar. If you’re using
stone intended to
look like it’s dry-stacked—that is, no
mortar between the
finish the job by
grouting the joints
between the stones
Marcus the Mason
Marcus Schilling was introduced to the world of masonry when he was only about 7 years old. He helped his dad with all sorts of stonemason tasks, including carrying small stones and cleaning up at the end of the day. And he loved it from the start. His grandpa was a stonemason. His grandpa taught his dad, and his dad taught Marcus and his brothers. And now Marcus is teaching his sons—and us!—the
craft of setting stones and laying bricks.
Tip 1: Cut wire lath the easy way
Wire lath can be unruly, and the cut edges are
sharp. So anything you can do to keep the stuff under
control while you’re cutting it is a big bonus. Here’s a
tip from Marcus on how to make long cuts. Lay the
wire lath on some long boards. Measure from the
edge of the lath to the edge of the board on each
end so the desired cutting line is lined up with
the edge of the board. Then secure the lath
temporarily with a few staples. Now use the
edge of the board as a guide to make the cut.
Marcus uses cordless metal shears, but tin
snips or aviation snips will also work.
More tips for working with lath:
- Wear gloves and safety glasses.
- Cut wire lath with large tin snips,
power metal shears or a diamond
blade mounted in an angle grinder.
- Prebend lath at inside corners. Bend it
over a board before putting it in place.
- Make sure the lath is installed so it
feels rough when your hand is going up, and smooth going down.
Tip 2: Speed up troweling for modern stone veneer
Marcus swears this is the fastest way to get the mud on
the wall. Prop up your mud board about 16 in. high and
within easy reach. Load it with mortar. Then use your
London trowel as shown to transfer the mortar from the
mud board to your trowel. Pull the trowel up the wall to
embed the mortar in the lath.
What kind of mortar should you use?
You’ll find recipes for mixing your own mortar in the stone
manufacturer’s instructions, but Marcus uses premixed Type
S mortar that’s labeled for use with veneer stone. Special
additives are already included—all you add is water. Look for it
at masonry suppliers or ask about it when you buy your stone.
Tip: When installing
use a colored mortar
or dye the mortar to
match the stones.
Tip 3: Use a tile trowel to scratch the mortar
Grooving or scratching the wet
mortar provides a better bond for
sticking on the stones. You can buy
a special rake-like tool for this, but
Marcus prefers to use a 3/16-in.
square-notched tile mastic trowel.
They’re cheap and easy to find at
home centers and hardware stores.
Simply drag it across the wet
mortar to make horizontal stripes.
Tip 4: Stick on the stone like a pro
Marcus makes a swipe across the entire back of the stone
with the trowel first to create a good bond for the
mortar bed. Then he wipes mortar from the trowel
all around the perimeter. This creates a little
hollow spot in the middle that will act as a suction
cup to hold the stone in place until the
mortar hardens. The key is to put on enough
mortar to create about a 1/2-in.-thick layer when
the stone is pressed against the scratch coat. If any
mortar oozes out around the edges, knock it off with
the trowel so it doesn’t get in the way of grouting.
Tip 5: Disguise the cut ends of stones
Occasionally you’ll have to cut stones to fit. Marcus
uses a 10-in. chop saw equipped with a dry-cut diamond
blade. But if you’re doing only one job, you
can get by with a diamond blade mounted in an
angle grinder. Regardless of the tool you use,
you’ll want to disguise or hide the cut ends. After
cutting a stone, Marcus cuts angles on the corners
to make them look more natural. You can
also use a tile nipper or horse-hoof trimmer
to chip away at the sharp edge left by cutting.
Marcus chooses thin stones to cut if
possible. Then he hides the cut edge against
a thicker stone. And if he’s using mortar that’s
dyed to match the stone, as you would in a dry-stack
installation, Marcus butters the end of the
stone so it blends in better.
Tip 6: Cut off the tip of the grout bag
Grout bags come with either metal or plastic tips. Marcus prefers
the plastic tips for grouting stone. He cuts the tip to create
an opening that’s about 5/8 in. in diameter to allow proper
mortar flow. Marcus says a common mistake is to mix grouting
mortar too stiff. Make sure the mortar is loose enough to ooze
from the tip without having to squeeze the bag.
Tip 7: Fill the joints completely
Marcus says he often encounters hollow
grout joints on work done by beginners. Be
careful to fill the joints full from back to front
as you’re grouting. Joints that are hollow
underneath will fall out later. Keep the tip
pressed deep into the joints so they get filled
from the back to the front of the stone.
Tip 8: Rinse the bags to avoid grout build-up
Marcus recommends rinsing out the
bag after every third bagful of grout.
Otherwise sand builds up along the
edge, clogs the tip and makes grouting
difficult. Just fill the empty bag
with water and rub it back and
forth to dislodge the caked-on
Tip 9: You don’t need a special tuckpointing tool!
Marcus finishes the joints
using a 3/8-in.-wide tuckpointing
trowel that he’s cut
off to about 5 in. long. He
says most masons prefer the
shorter length because it
gives them much better control.
But he says a carpenter’s
pencil is a great alternative.
It’s the perfect size and
shape for striking your grout
joints. Let the grout set up
until it’s firm to the touch
but not hard. Usually this is
about 20 to 30 minutes.
Then rake the pencil over the
grout to smooth and shape
it. Finish up by brushing off
any loose mortar with a soft
Back to Top
Tip 10: Wait! Don’t wipe off that wet mortar
When you spill a glob of mortar on the stone, which is
almost certain to happen, leave it alone. Let the mortar set
up about 30 minutes. Then flick the partially hardened
mortar off with the tip of the trowel.
Dab the remaining residue with a
damp rag to remove it.
Cleaning brush and vinegar
Morris Rozma, stone cleaning expert
Cleaning Manufactured Stone
A lot of people clean their manufactured stone wrong during installation, according
to masonry expert Morris Rozema. “People think they’ll do their cleanup at the
end of the project. But by then it’s too late to remove hardened mortar or grout
without the risk of damaging the stone. You need to clean up at least daily. This is
not optional, and I can’t stress this enough.”
When it comes to maintenace cleaning, scrub dirt off manufactured stone with a
stiff-bristle brush using a mild detergent and water. For tougher cleaning problems,
Rozema suggests using one part white vinegar mixed with eight parts water.
“Premoisten the stone with clean water, dip a plastic or brass brush (never use a
steel wire brush on manufactured stone) in the vinegar/water mix and lightly scrub
the area. Then rinse the area immediately with clean water to remove all of the
vinegar/water mix from the surface.”
Although most synthetic stone manufacturers warn against using harsh cleaning
or bleaching products or pressure washers on their stones, Rozema says he’s
used them on severely stained and moldy areas of stone at
his own home without adverse effects.
“But I always test the cleaner or bleach in an out-of-the-way
area to see if the stone or mortar color runs.” Rozema
cautions that the use of virtually all cleaners/bleaches/acids
or pressure washers can void the manufacturer’s warranty.
“If you use these things, proceed with extreme caution and at
your own risk.”
Meet the cleaning expert:
involved in the
more than 40
years and is
Stone & Brick,