Installation

Ensure that building codes and permit requirements will be met.

You can save considerable expense by installing stones yourself, in the range of $14 - $22 per square foot for labor.  Before proceeding with your project you should be sure that you will not violate any building codes and that you have any required permit for the work.

Ensure the application surface is suitable.

The surface behind the stones must meet criteria based on whether it is an existing surface or a newly created surface.

In the case of an existing surface, the primary consideration is whether the texture is suitable for mortar adhesion, or whether it can be made suitable.  Existing block wall provides an ideal texture, whereas poured concrete will probably not be porous enough.  Painted, dirty, or otherwise treated surfaces can usually be converted by means of sandblasting or addition of anchors. 

With new outdoors surfaces the primary consideration becomes, “What will happen with the water?”  Especially with wood construction the wall should be completely weatherproofed with an approved moisture barrier like tar paper or RainGuard. The barrier should be lapped four inches.  Weep drainage should always be provided at the bottom course.  Windows, electrical and plumbing outlets, and any other wall easements should be weatherproofed.

Calculate the amount of stone needed.

As an example, suppose your project consists of a flat wall area five feet high by eight feet wide and two square column bases which are two feet wide by five feet high.  To calculate the square feet of stone needed you would multiply the length times the height of all areas:

Wall area: 5 x 8 = 40 

Four sides per column times two columns: 2 x 5 x 4 x 2 = 80 

Total is 120 square feet.

Now add all the side heights for the corner stone lengths needed:

5 x 2 = 10 for the wall

5 x 8 = 40 for the columns

Total is 50 linear feet of corners.

These corners will overlap into the wall area, so we can subtract half of the corner lengths from the wall total:

New total for walls: 120 – 25 = 95

Now add 5 – 7% for cutting to fit and breakage – for both walls and corners:

Add for walls:  95 x .06 = 5

95 + 5 = 100

Add for corners: 50 x .06 = 3

50 + 3 = 53

Final total is 100 square feet for walls and 53 lineal feet for corners.

Installation considerations

Manufactured stone is not chemically similar to natural stone.  Perhaps the most important thing to keep in mind is that natural stone can be cleaned of mortar more easily than manufactured stone.  This is because one of the elements in the manufactured stone is the same as in mortar.  You must not use muriatic acid on manufactured stone.  Otherwise all other aspects of installation are either similar or easier than with natural stones.  River Rocks and Quick Bricks are generally installed top down.  This is possible because of their relatively light weight and desirable because it precludes dripping mortar which would have to be cleaned off.  If mortar should get on a stone’s surface, remove it with a stiff-bristles brush once is it has dried sufficiently.  To ensure a level application, Ledge Stone should be applied from the bottom up, finishing each course before beginning the one above.

Requirements for temperature and weather are the same as for regular masonry practice.  Temperature should be above freezing before, during, and at least one day after installation.  Medium to heavy rains will damage the mortar work until at least a day of curing has passed.  Ideal temperature range is 50 – 77 Fahrenheit.  Above 80 degrees it is desirable to shade the work and take precautions to avoid the mortar setting up prior to proper joint finishing.

Surfaces for Installation

Because of its lighter weight, manufactured stone does not require footings.  Backing surface requirements are similar to those of normal masonry, with the difference being in the need for a rough and moist mortar surface attachment vs. the typical joint clips used for heavy masonry walls.  Metal screen lath provides plenty of strength and is the ideal.  In situations where nails or screws can be used, SpiderLath provides good adhesion with the least effort among the alternatives.

Back surfaces may be walls of untreated plaster, stone, brick, block, wood, or metal studs.  Poured concrete will usually be too smooth for adherence without addition of anchors.  Wire or metal lath provides excellent mortar adhesion.

If the given surface is not sturdy and rough enough to hold a coat of mortar, it must be changed toward such purpose.  The general approach is to anchor a surface of mortar board (Duraroc), lath, spiderLath, or some equivalent onto the given surface.  Galvanized nails or rust proofed screws will do this job in most cases.  A scratch coat of mortar on this frontal surface will then be used as the meeting place for fresh mortar applied to the backs of your manufactured stones.  Always attach lath right side up with small cups pointing upward. Building paper should be applied on exterior surfaces prior to the lath.

For new or exposed walls, over-lapped felt building paper is the minimum requirement for weather-proofing.  Drainage mat behind the stones will allow water to vent downward to the bottom weep system, which may include a weep screed along the bottom course.  Nothing within these installation guidelines should be construed to take the place of local building codes. 

Installation Procedure

Mix masonry cement approximately 2:1 sand to cement. Add mortar color if desired. Gradually add sufficient water so that when the mixture is thrown against the wall, it adheres.

Optional: Apply an even coating of cement (scratch coat) to your wall surface and lightly scratch with a hair pick. Allow to dry overnight. This acts an additional water barrier and "grabbing surface" for your stone.

Start with the corners.  If the stones are to be in level courses, set the opposite corner stones level with each other.  Depending on stone style, start filling in at the top (quick bricks, river rocks) or at the bottom (ledge stone).

Spread cement on the wall approximately 1/2" thick covering a small area at a time until you are acquainted with the procedure, so that the cement won't set before the stone is in place.

Apply ½” – ¾” mud on the back of stone and push against surface using a slight wiggle motion for better adhesion. Mortar should seep out from behind the stone if a sufficient amount was applied.

Allow cement to set up about about 15 minutes, depending upon the temperature and humidity, before smoothing joints between stones. CLEAN STONES WITH BRUSH AND WATER BEFORE CEMENT HARDENS ON THEM.  DO NOT USE MURIATIC ACID!