How to Install Stone Veneer on Exterior Concrete Wall
Masonry Installation Tips
Natural Stone Veneer
1. A Solid Footing
Whether you are veneering a garden wall or a cinder block foundation on a building, it is important that the veneer rest on a solid footing. If the structure's existing footing extends at least 4" beyond the wall's face, you can simply flash the footing and lay the veneer over the existing footing. If not, you can either extend the existing footing to support the veneer or bold a steel angle iron to the wall at ground level and lay the veneer on the angle iron.
If you elect to extend the footing, check with your local building authorities to obtain specifications for making the footing extension and tying it to the existing footing.
2. Preparing the Wall Surface
Unsealed Masonry: Stone veneer can be installed directly over cleaned, unsealed masonry walls using wall ties fastened to the existing structure. Fasten the wall ties with masonry nails or masonry screws. Install one wall tie for each square foot of wall surface to be covered.
Wood: Nail double D paper to the wood to create a vapor barrier. Then apply one wall tie every square foot.
The scratch coat of mortar provides a good masonry surface for laying the stone.
Laying the Stone
1. In a wheelbarrow or mud box, mix a bag of mortar to roughly the consistency of mashed potatoes.
2. Starting at one end of the wall, working side to side and vertically, put down 1/2" - 1" of mortar as the base for the stone. As you set the pieces of the stone try to keep them all level. Put approximately the same amount of mortar between each piece to keep the joints even. As you stack the pieces of stone, leave a small space between the stone and the wall; this allows for any moisture in the wall to drain easily.
3. Apply a thin coat (1/4" to 1/2" thick) of mortar to the entire wall. Let this base coat dry for 12-24 hours. After 12-24 hours, come back to begin laying the stone.
4. Note that as you lay large stones, it may be necessary to place smaller stones in gaps and along uneven edges to fill in the wall. It may also be necessary to use the brick chisel to cut stones at the ends of the wall. Selecting good stones for the edges before you start on the wall reduces the need for chiseling and makes your work look more natural.
5. Apply the next courses in the same manner as the first. Be sure to interlock each course so that the joints are staggered from course to course.
6. If you are veneering the foundation of a structure, flash the top course to keep water from getting behind the stone. If you are veneering a garden wall, stop slightly short of or even with the top of the wall. Cap the wall with stone laid horizontally across its top, or a natural cutstone wall cap.
7. If you are only partially veneering the front of a house or other structure you will want to install a sill plate. Install the sill plate above the stone at an angle sloping away from the house to prevent water from getting behind the stone. Also install flashing above the sill plate to help direct the water.
8. Once the mortar has hardened some, but not completely set, use a jointer or the point of your trowel to dress the joints.
9. Clean any mortar from the face of the stones with a stiff-bristled brush. Do not allow mortar to set on the face of the stone.
Natural Stone Thin Veneer
1. Preparing the Wall Surface
Unsealed Masonry: Stone veneer can be installed directly over cleaned, unsealed masonry walls using metal lath fastened to the existing structure. Fasten the lath with masonry nails or masonry screws.
Sealed Masonry: If you can sand blast or otherwise remove the sealer, install the veneer as you would over unsealed masonry. If the sealer can not be removed:
1. Use masonry nails or masonry screws to fasten metal lath to the existing structure.
2. Apply a scratch coat of mortar mix (at least 1/2" thick) to the metal lath. Be sure to work the mortar mix into the lath.
3. As the mortar begins to set, use a brush to rough up the scratch coat and allow the coat to set completely. The roughness provides a good bonding surface for the mortar used to adhere the stones.
4. Wood: Nail double D paper to the wood to create a vapor barrier. Then apply metal lath and a scratch coat of mortar as above.
The scratch coat of mortar provides a good masonry surface for laying the stone.
Laying the Stone
1. In a wheelbarrow or mud box, mix a bag of mortar to roughly the consistency of mashed potatoes.
2. Apply a thin coat (1/4" to 1/2" thick) of mortar to the entire wall. Let this base coat dry for 12-24 hours. After 12-24 hours, come back to begin laying the stone.
3. Butter the back of a stone with about 1/2" of mortar.
4. Press the stone into the bottom of the wall. Wiggle the stone slightly back and forth until it seats against the wall. Take care not to press all the mortar mix from between the stone and the wall.
5. Continue laying the bottom course to the end of the wall. Note that as you lay large stones, it may be necessary to place smaller stones in gaps and along uneven edges to fill in the wall. It may also be necessary to use the brick chisel to cut stones at the ends of the wall. Selecting good stones for the edges before you start on the wall reduces the need for chiseling and makes your work look more natural.
6. Apply the next courses in the same manner as the first. Be sure to interlock each course so that the joints are staggered from course to course.
7. If you are veneering the foundation of a structure, flash the top course to keep water from getting behind the stone. If you are veneering a garden wall, stop slightly short of or even with the top of the wall. Cap the wall with stone laid horizontally across its top, or a natural cutstone wall cap.
8. Once the mortar has hardened some, but not completely set, use a jointer or the point of your trowel to dress the joints.
9. Clean any mortar from the face of the stones with a stiff-bristled brush. Do not allow mortar to set on the face of the stone.
Clay Brick
1. If you'll be installing the brick product on an exterior project, current building code requires a moisture barrier such as 2 layers of tar paper or two-ply 60 minute grade D paper be applied directly to the buildingâ¬"s surface. Be sure to lay the tar paper from the bottom up so that the top sheets overlap the bottom. Overlap 2" on the horizontal seams and 6" on the vertical seams. Check your local building code for other specific moisture barrier requirements in your area.
2. Directly over the tar paper, or directly over the sheeting on an interior project, cover the area with wire lath. A 3.4 diamond wire lath is recommended.
3. Hang the lath horizontally.
4. Overlap the lath at least 6" on the vertical seams, and at least 2" on the horizontal seams.
5. The lath should feel rough as you run your hand up over it, and smooth as you run your hand down over it.
6. Use a hammer and 1 3/4" roofing nails, or an air stapler to fasten the lath to the studs every 6". Then use an air stapler or a hammer tacker to fasten any loose areas or bulges between the studs.
7. Cut the lath using a tin snips.
8. When working with corners, fold the lath tightly around the corner, and overlap a new piece on the other side as you would anywhere else. This rule applies for inside corners also; fold the lath at a 90 degree angle and fit it tightly into the corner, overlapping the lath on each side.
9. Never have a seam on a corner.
10. It is very important to nail the lath on both faces of the corner.
11. You will need to mix three separate batches of cement, one for the scratch coat, one for the mortar, and one for the grout. Each requires a specific ratio of sand, and either Portland or Masons cement.
- Scratch Coat - 1 part Portland cement to 21/2 parts sand
- Mortar - 1 part Portland cement to 2 parts sand
- Grout - 1 part Masonâ¬"s cement to 2 parts sand
Note: An alternative cement for interior work only is to use "Type M" cement for the scratch coat, mortar, and the grout. The ratios of cement to sand remain the same. Pre-mixed mortar is okay too.
12. Dry mix the sand and cement together with a hoe in a wheelbarrow or mud box. This will avoid creating clumps in the mixture.
13. Slowly add water to the mixture a little at a time and continue to mix. You can always add more water later, but if you add too much, the mixture will become runny and unusable.
14. Continue mixing the cement adding small amounts of water as needed until it has the consistency of paste.
15. Use a masonry trowel to spread an even layer of cement over the wire lath. Cover the entire area of lath with the cement mixture. Work the cement into the holes of the lath, and scrape off the excess.
16. While the cement is still slightly wet, use a soft bristled brush to rough up the scratch coat a little. This will give the brick a better surface to grab to. Virtually no cement should be removed with the brushing process.
17. Let the scratch coat dry before going on to the next step. Drying time will depend on temperature, humidity and airflow, and could take anywhere from 2 to 24 hours. Youâ¬"ll know its dry when it turns a light gray color.
18. When the scratch coat has dried, snap chalk lines to course out the brick. Snap chalk lines every 5 1/2" for new pattern brick, and every 5 3/4" for used pattern brick. This includes enough room for 2 bricks, and grout joints.
19. Mix a batch of mortar, using 1 part Portland cement and 2 parts sand.
20. Lay alternate courses below each chalk line, keeping end joints plumb. Wait until the bricks have dried before laying the other rows to prevent accidentally nudging the bricks above and below out of place.
21. Work from the top down to prevent cement from dripping on bricks beneath.
22. To lay the brick, use a trowel to spread about a 1/2" layer of mortar to the back of the brick. Lay the brick against the wall, press and shake it gently into place.
23. There are no special pieces for working on inside corners, just meet the two pieces together.
24. Any power saw with a masonry blade will work. This cutting will be very dusty, so be sure to wear safety glasses and a dust mask and do all cutting outdoors.
25. Mix a batch of cement with 1 part Masons cement and 2 parts sand.
26. Cut about a 3/8" - 1/2" hole in the tip of your grout bag. Itâ¬"s best to start by cutting a smaller hole, and you can always cut more later, but if the hole is too big, the cement will drip out and stain the brick.
27. Fill your grout bag about half full with the grout mixture.
28. Twist the top end of the bag and squirt some grout back into the bucket. This will prevent air pockets from causing the grout to accidentally squirt out explosively.
29. Keeping the top end of the bag twisted, gently squeeze the grout into the joints. Fill all the gaps between the bricks with about a half inch layer of grout. The grout will tighten and seal up the area around the brick.
30. Let the grout dry until it is firm but not solid. You want to be able to push on it without leaving fingerprints, but donâ¬"t let the grout turn gray or it will be very difficult to strike.
31. We recommend using a hardwood stick such as oak for striking. Keep the sticks square by cutting the tops off of them if they get worn down.
32. Striking the grout gives your project a finished look. Use your striking stick to scrape along the joints until the grout has a clean, even look to it.
33. The grout should crumble away like sand. If it smears, or crumbles away in large chunks, that means the grout is still too wet.
34. Finally, use your soft bristled brush to sweep the dust off the brick.
Manufactured Stone Veneer
1. If you'll be installing the stone product on an exterior project, current building code requires a moisture barrier such as 2 layers of tar paper or two-ply 60 minute grade D paper be applied directly to the building's surface. Be sure to lay the tar paper from the bottom up so that the top sheets overlap the bottom. Overlap 2 inches on the horizontal seams and 6 inches on the vertical seams. Check your local building code for other specific moisture barrier requirements in your area.
2. Directly over the tar paper, or directly over the sheeting on an interior project, cover the area with wire lath. A 3.4 diamond wire lath is recommended.
3. Hang the lath horizontally.
4. Overlap the lath at least 6 inches on the vertical seams, and at least 2 inches on the horizontal seams.
5. The lath should feel rough as you run your hand up over it, and smooth as you run your hand down over it.
6. Use a hammer and 1 3/4" roofing nails, or an air stapler to fasten the lath to the studs every 6 inches. Then use an air stapler or a hammer tacker to fasten any loose areas or bulges between the studs. A shorter length staple is okay for use between studs.
7. Cut the lath using a tin snips.
8. When working with corners, fold the lath tightly around the corner, and overlap a new piece on the other side as you would anywhere else. This rule applies for inside corners also; fold the lath at a 90 degree angle and fit it tightly into the corner, overlapping the lath on each side.
9. Never have a seam on a corner.
10. It is very important to nail the lath on both faces of the corner.
11. You will need to mix three separate batches of cement, one for the scratch coat, one for the mortar, and one for the grout. Each requires a specific ratio of sand, and either portland or masons cement.
Scratch Coat - 1 part Portland cement to 2 1/2 parts sand
Mortar - 1 part Portland cement to 2 parts sand
Grout - 1 part Mason's cement to 2 parts sand
Note: An alternative cement for interior work only is to use "Type M" cement for the scratch coat, mortar, and the grout. The ratios of cement to sand remain the same. Pre-mixed mortar is okay too.
12. Dry mix the sand and cement together with a hoe in a wheelbarrow or mud box. This will avoid creating clumps in the mixture.
13. Slowly add water to the mixture a little at a time and continue to mix. You can always add more water later, but if you add too much, the mixture will become runny and unusable.
14. Continue mixing the cement adding small amounts of water as needed until it has the consistency of paste.
15. Use a masonry trowel to spread an even layer of cement over the wire lath. Cover the entire area of lath with the cement mixture. Work the cement into the holes of the lath, and scrape off the excess.
16. While the cement is still slightly wet, use a soft bristled brush to rough up the scratch coat a little. This will give the stone a better surface to grab to. Virtually no cement should be removed with the brushing process.
17. Let the scratch coat dry before going on to the next step. Drying time will depend on temperature, humidity and airflow, and could take anywhere from 2 to 24 hours. You'll know its dry when it turns a light gray color.
18. Mix a batch of mortar, using 1 part portland cement and 2 parts sand.
19. Before you apply any of the stone, lay out a couple of boxes in front of your project. This will give you a sense for the variety of shapes and colors you'll be working with. Arrange the pieces so they fit and look nice next to each other, and try to avoid clumping colors together all in one area.
20. Start at the corners and work toward the center of the wall. Be sure to alternate long and short returns on corner pieces.
Dry Stackable Patterns
With these patterns, you should work from the bottom up. There are no joints or gaps between these pieces of stone, the pieces stack directly on top of the pieces below, and tightly against the pieces next to it. Be sure to check your work often with a level. If you'll be working with one of these dry stackable patterns, it is recommended you mix your mortar with a latex bonding agent, available from your supplier. Also, these stones should be laid in rows of pieces with the same height, so that when you start each row, you should have a flat level surface to work on.
1. With some patterns, it's a good idea to lightly etch guide lines into the scratch coat, using a 4' level and a pencil.
2. It's always a good idea to size the stone up before you apply any mortar, just to make sure it will fit properly and look good next to the other pieces.
3. To lay the stone, use a trowel to spread about a 1/2 inch layer of mortar to the back of the stone. Lay the stone against the wall, press and shake it gently into place.
4. There are no special pieces for working on inside corners, just meet the two pieces together.
5. Any power saw with a masonry blade will work. This cutting will be very dusty, so be sure to wear safety glasses and a dust mask and do all cutting outdoors. Other times you may want to break the stone to keep a more natural looking rough edge. You can use a nipper to trim small amounts off the stone, or the back of your masonry hammer to crack a piece in half.
Non-Dry Stackable Patterns
Whenever possible work from the top down to prevent cement from dripping on stones beneath. That is unless you're working with one of our drystackable patterns, which are designed to be laid from the bottom up.
1. Size the stone up before you apply any mortar, just to make sure it will fit properly and look good next to the other pieces.
2. To lay the stone, use a trowel to spread about a 1/2" layer of mortar to the back of the stone. Lay the stone against the wall, press and shake it gently into place.
3. There are no special pieces for working on inside corners, just meet the two pieces together.
4. Any power saw with a masonry blade will work. This cutting will be very dusty, so be sure to wear safety glasses and a dust mask and do all cutting outdoors. Other times you may want to break the stone to keep a more natural looking rough edge. You can use a nipper to trim small amounts off the stone, or the back of your masonry hammer to crack a piece in half.
5. Mix a batch of cement with 1 part masons cement and 2 parts sand.
6. Cut about a 1/2" hole in the tip of your grout bag. It's best to start by cutting a smaller hole, and you can always cut more later, but if the hole is too big, the cement will drip out and stain the stone.
7. Fill your grout bag about half full with the grout mixture.
8. Twist the top end of the bag and squirt some grout back into the bucket. This will prevent air pockets from causing the grout to accidentally squirt out explosively.
9. Keeping the top end of the bag twisted, gently squeeze the grout into the joints. Fill all the gaps between the stones with about a half inch layer of grout. The grout will tighten and seal up the area around the stone.
10. Let the grout dry until it is firm but not solid. You want to be able to push on it without leaving fingerprints, but don't let the grout turn gray or it will be very difficult to strike.
11. We recommend using a hardwood stick such as oak for striking. Keep the sticks square by cutting the tops off of them if they get worn down.
12. Striking the grout gives your project a finished look. Use your striking stick to scrape along the joints until the grout has a clean, even look to it.
13. The grout should crumble away like sand. If it smears, or crumbles away in large chunks, that means the grout is still too wet.
14. Finally, use your soft bristled brush to sweep the dust off the stone.
Stone Flooring
Before You start:
Verify that rough grading is per plan and that paving will not be set on any uncompacted fill. Before setting final elevations, verify that walk and surrounding areas have adequate slopes and swales to provide drainage and proper runoff of surface water. If wall is to be laid on soil base, remove any loose soil and debris. If walk is to be laid on a concrete slab base, clean surface of any debris.
Dry Laid Installation
1. Preparing the Base
1. Sub-base shall be virgin or compacted soil.
2. Provide minimum 6" deep compacted gravel base.
3. Over base provide minimum 2" sand bedding. Screed, sprinkle, and compact until proper grade is reached.
Dry Laying the Stone
1. Stone shall be laid in specified pattern.
2. Color range should be uniformly distributed over total area of work.
3. Position stone tight to one another by lowering stone vertically into position.
4. Set stone by tapping with rubber mallet.
Joints
1. Spread fine dry sand over surface of stone and sweep into joints until completely full.
2. Wet surface with fine spray.
Cleaning
1. Sweep surface of stone to remove loose sand and chips.
Mortared Installation
1. Preparing the Base
2. Sub-base shall be virgin or compacted soil.
3. Provide a 4" concrete slab with reinforcement 1/2" steel rods or 6"x6" wire mesh.
4. Screed and bull-float leave rough.
5. Construction per standard concrete sidewalk practice.
6. Allow concrete to dry--next day application for stone.
Laying the Stone
1. Moisten concrete before laying stone--this helps bonding. Leave pallets wrapped so that moisture is retained in stone--if stone is dry, moisten to damp--not wet.
2. Spread 1/2" mortar on concrete slab, check that material is level.
3. Stone shall be laid in specified pattern with 3/8" mortar joint.
4. Color range should be uniformly distributed over total area of work.
5. Use a grout bag or hand tool to fill mortar between joints--pack joints. Make sure to keep the surface of the stone clean of mortar.
6. Tuck-point joints when 'thumb print hard' and brush smooth with flexible paint brush. Flush cut joints are not tooled and recommended for outdoor application.
7. When joints have hardened for 24 hours, clean stone with stiff brush and clean water only.
Indoor Mortared Installation
Preparing the Base
1. Sweep floor.
2. Apply 15# felt paper with staples for moisture barrier.
3. Staple or nail Diamond Mesh Wire.
4. Stone shall be laid in specified pattern with 3/8" mortar joint.
5. Color range should be uniformly distributed over total area of work.
6. Make sure stone is level throughout and keep mortar off stone surface.
7. Tuck-point joints when 'thumb print hard' and brush smooth with flexible paint brush. Flush cut joints are not tooled and recommended for outdoor application.
8. When joints have hardened for 24 hours, clean stone with stiff brush and clean water only.
9. Apply stone sealant. (Some sealers provide a gloss to the surface, or change the color--test the stone first, prior to application.)
** This information is provided in good faith. Hedberg Landscape Masonry & Supply is not liable for any damages related to your use or mis-use of the information. Use proper construction techniques and follow all safety instructions. Consult with a professional if needed.
How to Install Stone Veneer on Exterior Concrete Wall
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