Installing Thin Veneer
Tools and Materials
- Flat Trowel
- Grout Bag
- Sand and Cement
- Brick Trowel
- Wire Brush
- Joint Tool
- Masonry Brush
- Selected Stone
How to Install
Stone veneer may be applied over any masonry surface, concrete block, brick, cement, etc. Painted surfaces must be sandblasted, or otherwise stripped of paint. If it is difficult to remove paint or if surface is of frame construction, nail metal lath to wall securely, 6" on center, (for exterior, vapor barrier first, then metal lath). Apply a scratch coat (2 parts sand to 1 part cement) to lath. Make certain lath is covered completely with a thin coat (1/2"-3/4" thick). Use a metal scraper or small scrap of lath to lightly rake horizontal grooves in the scratch coat. Allow scratch coat to set up or cure. This is now a masonry surface to which the thin veneer may be applied using the following steps:
- Mix rich mortar (2 parts sand to 1 part cement) to a creamy consistency similar to whipped potatoes.
- Determine if stones will be laid out on ground to the desired fit prior to installation, of if trimming is required to complete finished application.
- Make certain surface is free of dirt, sand, or loose particles. If surface is dry, dampen first with a masonry brush but do not saturate. This prevents the wall from pulling the moisture from the mortar, allowing it to set up both naturally and with a better bond. For cleaner installation, begin applying stone at the top of the wall and work toward the bottom.
- Trowel rich mortar on wall approximately 1/2" thick.
- Take clean stone and slightly dampen the backside. The frees any dust and again prevents moisture loss form mortar.
- Apply thin coat of rich mortar onto backside of stone. This fills in pits and rises in stone and created a stronger bond with the wall.
- Press stone into mortar, rotating slightly, forcing some of the mortar to squeeze out freely. Any mortar forced out beyond the finished joint or on the stone surface itself must be removed with a trowel, joint tool, or brush before the mortar is allowed to set up. Narrow joints will provide a nicer appearance.
- Use a grout bag or trowel to fill all joints. As the mortar stiffens, tool to the desired depth and be sure to brush off all excess.
There are two basic ways of laying or setting "flagstone". One way is in a cement mortar on a concrete base; the other, a more simple way, is in Stone Dust.
How to Clean
Excess mortar and film may be removed using a 10% solution of Muriatic Acid and water and rinse thoroughly with clean water. DO NOT apply to limestone.
How to Seal
Stone may be sealed with a good quality sealer only after thoroughly curing which usually takes 3 to 4 weeks on inside work. Follow manufacturer's directions on the application of sealer. Sealed stone is easier to clean than unsealed stone and certain sealers also repel water. However, sealers must be periodically reapplied, especially on exterior applications, and could alter the natural coloring of the stone.