Step1: Prepare the Surface
A. Apply exterior surfaces with a moisture barrier starting from the bottom upward, and put on a 3.4 diamond wire lath for the surfaces’ interior and exterior
B. The lath should be hung horizontally. The lath should be lapped over 2” on the vertical and 6” on the horizontal seams. Then, wrap the lath around the corners.
Step 2: Mixing the Cement
A. Scratch coat: 1 part Portland Cement. 2.5 parts sand.
B. Mortar: 1 part Portland, 2 parts sand.
C. Grout: 1 part Mason’s cement to 2 parts sand. Dry mix sand and cement together in a wheelbarrow or mud box. Continue mixing and add water slowly until you get a more pasty substance
Step 3: Scratch Coat
A. After the cement mix, use a masonry towel to apply an even layer over the entire wire lath, including the holes. Use a brush to roughen the scratch coat a little. Allow 24 hours for drying.
Step 4: Apply Stone
A. Put in the corners first and begin from the top working down. Apply 1/2 inch mortar layer to the stone’s back side, place it against the wall, and shake gently into place.
B. Cut stone with power saw.
C. Cut a half inch hole in the grout bag’s tip. Fill the bag with cement half full and twist it’s top. Squeeze some back into bucket to rid air pockets.
D. Squeeze grout in the stone, then let it dry. Make sure it is firm, but not very hard. Take and use a stick to wipe around the stone. Lastly, remove sand with a brush.
Quantities of material needed
1. How to determine the total project square footage
Multiply the length of the area covered times the height of each surface area to be covered. Then subtract the area of all opening such as, doors and windows. Add 10% for waste and cut.
2. How to determine the lineal footage of corners
Measure the lineal feet of the outside corner area to be covered, including any doorways and window that’s will have corners. Add 10% for waste and cut.
3. How to know and determine the square footage of flat stone required.
Divide the lineal footage of corner stones needed by half and subtract it from the total project square footage. This gives you the total square footage of flat stone required. However, acquiring extra pieces is recommended for trimming and tight fits.
How to prepare for different surfaces
Over Sheetrock, paneling, wallboard, plywood or other rigid wood related sheathing.
Wall surface needs o be covered with a weather resistive barrier. Barrier shall be equal to the U.B.C Standard No. 14-1 for Kraft waterproof building paper or asphalt-saturated rag felt. Building paper shall be applied horizontally with the upper layer over lapped the lower layer not less then 2 inches. If vertical joints occur, the paper shall be lapped not less then 6 inches. From there install a 2.5 lb diamond mesh expanded metal lath or a 18 gauge woven wire mesh.
Lath sides need to be overlap by no less than 3/8 inch and lath end by no more than 1 inch. The spacing for nails or staples should be 6 inches on center vertically and 16 inches on center horizontally, penetrating studs a minimum of 1 inch.
Over rigid insulation board
Surface preparations is the same as preparing over sheetrock, paneling, wallboard, plywood or other rigid wood related sheathing.
Over metal panels
The preparation for the surface is the same as for “over sheetrock, paneling, wallboard, plywood or other rigid wood related sheathing”. ( see instructions above)
The metal lath should be attached using self-tapping screws with a 3/8” which provides a 3/8” minimum penetration beyond the inside metal surface.
Over painted, sealed or treated
Brick, Block, concrete or other masonry surface.
The surface must either
A. Exposed the original surface by cleaning with sandblasting acid etching, water blasting, or wire brushing.
B. Attached a metal lath, by wiring corrosion resistant concrete nails with a scratch coat applied over the metal lath.
Over clean, brick, block, concrete or other masonry surface.
(unpainted, unsealed, untreated)
Surface preparation is necessary. However to minimize cracking or bond failure, using a metal lath and scratch coat is also needed. Newly poured concrete needs to be examined closely to ensure the surface does not contain form oil or other types of release agents. Spray surface with water to determine the presence of release agents. If water beads up or runs off the wall, the presence of a release agent is likely to be there. If a lease agent is present you should use an acid etch, wire brush surface or use a metal lath and then a scratch coat. It is imperative that the concrete surface is free of form release contamination if lath and scratch coat is not used to ensure a proper bond.
Over open studs
With galvanized nails or staples apply a paper-back galvanized 3.4 lb 3/8 inch rib expanded metal lath to the studs every 6 inches vertically on center. Make sure to have a one-inch penetration. The lath sides will have a over lap of less than ½ inch and lath ends by not less than 1 inch. When using metal studs, you will need to use corrosion-resistant self-tapping screws that have a 3/8 inch head and provide a 3/8 inch penetration. Lastly apply a ½ inch mortar scratch coat on top of the lath and let it set for at least 48 hours.
How to prepare the mortar
Mortar mix for installation
I. Using type-N or type-S mortar mix
A. Using suggested mix type-N mortar
2 parts type-N masonry cement and 3 to 5 parts masonry sand water
B. Alternative mix type-S mortar
3 parts type-S masonry cement and 5 to 7 parts masonry sand water
II. 2nd option using lime
A. 1 part Portland cement
1 part lime
3 to 5 parts masonry sand water
B. 2 part Portland cement
1 part lime
5 to 7 parts masonry sans water