There are two basic stone installation methods giving Old Southern Stone (OSS) two distinctive appearances: Dry stacked is one
of the most current and commonly used applications. When the dry stacked method is used, all the stones are fit tightly together
with no visible mortar joints. The standard, more traditional, method has a mortar joint between all the stones. Most of the
installation procedures are the same for both variations. The differences will be outlined in this instruction guide.
I. Estimating the Stone Required
Flat and corner stones are used for installation. Flat stones are used for all flat wall applications and are ordered in square
footage. Corner stones are used on all outside corners and are ordered in linear footage. Water tables, window sills, cap stones,
and hearthstones are also ordered in linear footage.
1. Determining the Total Footage Needed. Take the width and multiply it by the height of all the flat surface areas that need
to be covered. When measuring, deduct for all window and door openings.
2. Determining the Linear Footage of Corner Stone Needed. Measure all the linear footage of outside corners including
columns, doors and windows if needed.
3. Determining the Square Footage of Flat Stone Needed. One linear foot of corner stones will take up ½ a square foot of
wall space. Take the total linear footage of corner stones and multiply by .5 and subtract that number from the total footage
needed. This will give the you the total square footage of flat stone need.
4. Determining the Waste: It is recommended that you purchase an additional 5 to 10% of stone to for cutting and trimming
for a proper fit. When using OSS add 5% to our Cobble stone, Ledge stone, Fieldstone and Carolina Blend. Add 10% to our
Shadowrock and Mountain Blend.
II. Additional Materials Required
1. Mortar Components: Type S mortar mix is recommended. Mortar should be mixed with 2 parts masonry sand to 1 part
mortar. Iron oxide may be used to add color variations to standard mortar.
2. Weather Resistant Barrier: All exterior and interior mortar applications except over concrete, masonry and stucco require
a weather resistant barrier. Confirm with local building codes on the proper weather resistant barrier for your area. The most
common weather resistant barrier is felt paper also known as building paper. When installing felt, lap all horizontal joints
with the upper piece overlapping the lower by a minimum of 2 inches. All vertical joints should be lapped no less than 6 inches.
There should be no vertical joints in the weather resistant barrier any closer than 16 inches from an inside or outside corner.
3. Flashing: To maintain a weather resistant exterior, where stone will be applied, rigid, corrosion resistant flashing should
be installed at the point of all penetrations and terminations of the stone veneer. Consult you local building official for flashing
types and locations.
4. Metal Lath: A minimum of 2.5 lb galvanized diamond mesh, metal lath should be used when preparing any rigid
backwall surface (wall board, plywood, OSB, paneling, concrete board or polystyrene over a rigid back wall) for OSS veneer,
meeting the requirements of ATSM 847. It is important that metal lath is attached with the small diamonds pointing up.
Metal lath shall be lapped no less than ½ inch on vertical butt end and 1 inch on horizontal laps. Metal lath should not lap any
closer than 16 inches from an inside or outside corner. When attaching metal lath to wood studs, galvanized nails or staple may
be used, spaced no more than 6 inches vertically and 16 inches horizontally, penetrating the stud a minimum of 1 inch.
When attaching to metal buildings and open stud construction use 3.4 lb, 3/8 ribbed, paperback metal lath. Attach the metal lath
with galvanized self tapping screws with a minimum 3/8 inch penetration.
III. Preparing the Surface for Installation
1. Rigid Backwall Installation: Cover the entire surface area where OSS veneer will be applied with a weather resistant
barrier and install all necessary flashing.
2. Clean and Untreated Concrete, Masonry, and Stucco: Check poured concrete closely, to see if the finished surface
contains any release agents such as form oil. If it does, acid etch the area and rinse thoroughly as this will prepare the surface for
an adequate bond. No further preparation needed.
3. Dirty, Painted, or Sealed Concrete, Masonry and Stucco: For the stone to bond, the surface area needs to be free of any
foreign substance such as paint, dirt, or sealers. If these substances are present, sandblast or water blast until the area is clean
and free of these foreign substances. If the area cannot be cleaned completely, metal lath can be nailed to the concrete, masonry,
or stucco using galvanized concrete nails.
4. Metal Buildings: Apply paper backed metal lath using adequate galvanized screws over a primary weather resistant
IV. Installation Procedures
1. Lay Out the Stones: It is recommended that prior to installation a quantity of stone should be laid out giving you a good
idea of the shapes, sizes, depths and color pattern. This allows you to visualize the desired pattern and give you a selection of
stone to choose from. Thick stones should be place beside thin stone, wide beside narrow, smooth beside textured. Mix stones
from several boxes to ensure a good blend of sizes and color.
2. Mixing Mortar: Mortar can be mixed in a mechanical mixer or by hand. Mortar for OSS stone veneer is mixed very similar
to brick or block mortar, the only difference is the amount of sand. Mortar for stone has less sand which gives the mix more
Portland cement per unit. This gives more bonding power to the mortar. The mortar should be mixed 2 parts sand to 1 part type S
mortar mix, water should be added to obtain the proper slump.
3. Appling Metal Lath: The weather resistant barrier, flashing and metal lath should be applied according to the directions
outlined in section II.
4. Appling the Scratch Coat: A ½ inch coat of mortar should be applied to the metal lath using a mason’s or plaster trowel
and allowed to dry. Scratch the surface area to allow for a good bond when setting the stone.
5. Setting the Stones: OSS stone veneer can be installed from the top down, but the most common method is from the
bottom up. A masons level should be used periodically to ensure the stones are installed level and plumb. Level chalk line can be
applied to the scratch coat to assist in proper installation. Completely cover the back surface of the stone with ¾ inch of mortar
and firmly press onto the prepared wall allowing mortar to squeeze out around the stones edges. Use trowel to strike off excess
mortar before installing the next piece. All corners have a long and short side, these should be alternated in opposite directions as
you apply them. To simplify installation, stone around windows, doors and corner stones should be installed first.
6. Consistent Joints: Whether you are doing a dry stack or a mortar joint application, all joints should be consistent. Cutting
and trimming the stones may be necessary to achieve the consistent and desired joint.
7. Cutting and Trimming Stones: Stones can be cut to obtain the desired fit, by using a hatchet, nippers or an electric saw
with a diamond blade. Cutting should be done outside using safety glasses and a dust mask. Cut edge should be hidden from
sight. To conceal the raw edges cover with mortar when installing. Cut edges should be position up when above eye level and
down when below eye level.
V. Joints and Grouting
Grouting may be necessary or desired after stone is set in place. Grouting technique can give the stone many different
appearances. If mortar smears when grouting , allow to dry and brush with a soft bristled brush. Never use a wet or a wire brush
to remove a mortar smear.
1. Drystack: Drystacked stone installation is achieved by stacking the stone with little or no joint at all. When setting
the stone mortar will seep between the stone, once the mortar is set, striking the joint with a sharp object will give the appearance
of no joint at all.
2. Standard Joint: This is achieved by laying each stone approximately ½ to ¾ inch apart. Once stone is laid, fill grout bag ½
full of mortar and squeeze mortar into joint area filling any voids. When the mortar becomes firm or thumb print dry, it should be
pointed up with a wooden stick or a metal jointing tool. Rake out mortar to the depth desired. Even joints will give a professional
3. Over Jointing: This technique is becoming more popular, giving the stone an old world rustic appearance. The stone is
set similar to the standard joint, however grouting should overlap the stone, widening the joints and making them irregular. This
technique is used in the OSS cobble and field stone profiles.
VI. General Information
1. Cleaning: To clean dust, mud, dirt, and other debris from the stone, use detergent or a granulated soap product mixed
with water. Scrub with a soft bristled brush and rinse with water. Do not used a wire brush, high pressure power washer tip or
any product that contains acid, as this may create an undesirable result.
2. Pools and Fountains: OSS stone veneer is not recommended in any area that has constant contact with chlorine or
other water chemicals. Stone below water levels can result in discoloration as would any concrete product.
3. Salts and De-Icing agents: Do not use salts or other chemicals to remove snow and ice immediately adjacent to the
surface of OCS stone.
4. Scuffing: Scuffing occurs on naturals stones when palletized the stones rub together creating these marks. In most
cases this enhances the appearance of the stone. If scuff marks need to be removed , clean with soap, water and a soft bristled
5. Efflorescence: Efflorescence is a water soluble salt that penetrates the surface of veneer stone, stucco, mortar, brick and
other masonry products. On rare occasions it may occur on OSS stone. To remove, mix 1 part vinegar and 5 parts water and scrub
with a soft bristled brush and rinse with water
6. Sealers: Sealers are not necessary on OSS products. A Silane based sealer can help with cleaning in areas where the
stone is susessable to dirt. Sealers may darken or change the color of the stone, therefore OSS recommend that testing the
sealer on individual stones to make sure results are acceptable.
7. Capping of Exterior Walls: When OSS stone is applied to the top of an exposed exterior wall, or retaining wall, it is
recommended that OSS capstones be used or a poured in place concrete cap to provide adequate runoff. Capstones should
project a minimum of 1 inch beyond the finished stone surface.
8. Capping of Chimneys: All chimneys chases must be capped with a one piece cap that extends 1 inch beyond the
finished stone surface to eliminate water from entering the chase.
VII. Good Building Practices
1. Building Code Requirements: Building code requirements vary from area to area. Check with local building authorities
for the requirements in your area. Proper building techniques are essential to the integrity of your project.
2. Cold Weather: OSS veneer stone should not be install unless temperatures are 38 degree F. and rising. If
temperatures are below 38 degrees, the mortar can freeze effecting its strength and color.
Old Southern Stone veneer products are covered 40 years from installation, when installed according to local codes and
manufacturer’s instructions. Old Southern Stone will replace any material deemed to be defective at no charge. This warranty is
limited to the original purchaser and is not transferable. This warranty does not cover damages resulting from: settlement of the
building or other wall movements; discoloration due to airborne contaminants; contact with any chemicals or pain; staining or
oxidation. Labor cost incurred in removal and replacement of defective products is not covered
2231 Highway 152 East
China Grove, NC 28023
Office (704) 799-0652
Fax (704) 799-0633