How To Install Cultured Stone: A DIY Project
Cultured Stone Fireplace
As with any masonry or concrete project preparing the substrate is most essential in installing cultured stone. This type of man-made, light weight material can be applied to all most any surface. The process is different depending on the surface. This material is great for cultured stone fireplaces, exterior veneer, or accent walls.
Prepping for installation over concrete , concrete block wall, brick or concrete board:
The best method is to use a portland cement sand mixture of about 25 shovels of sand to one 94lb bag of cement. Mix with water to achieve a workable consistency, Too dry and it wont spread, too wet and it will run off of trowel. Once you find your desired mix, simply take a masonry or brick laying trowel and apply to wall in even coats. It does not need to be tooled to a high finish, roughness is the desired texture for maximum adhesion.
Prepping for installation over wood or drywall:
Before applying the portland-sand mixture, you must first use a wire lathe. This can be purchased with the stone. The lathe can be installed using staples, nails or screws. It does not need to be lapped. If the stone is to be laid on the exterior or other place where it can come into contact with water, it is best to install a vapor barrier under the wire lathe.
How to install cultured stone
Cultured stone can be installed with or without joints. There are a few rules that can be applied to maximum aesthetics.
1 Lay all corners and chalk level lines between them. It is important that the corners on the adjacent side be level. Stone doesn't have to be laid in courses, but looks much better if laid level.
2. When laying drystack (without mortar joints) keep the stone as close as possible. Try to pick out stone that matches the contour as the one above or beside it. This also works well when using a mortar joint, but isn't as important.
3. Before laying drystack, add a dye to the portland-sand substrate to create an illusion of tighter joints. The dye should match the color of stone.
4. Never install a stone vertically. The length should be laid horizontally.
With these rules in mind and the substrate prepped, you are ready to learn how to lay cultured stone. Some masons prefer to start at the top to minimize the mess. I prefer starting at the bottom. It doesn't matter. Do what is convenient and easiest for you.
Start by separating stone is various thicknesses. Next, you need to mix up some mortar. I use type S premix and add a shovel of portland for better adhesion. I also put in a little dye, measured the same every mix, to match the stone. To install the stone, simply trowel mortar onto the back and wiggle into place, remembering to keep stone level. If laying stone with a mortar joint allow about 3/8 to a half inch in between each stone.
If you are laying stone with a mortar joint. the next step is to tuck the stone. I use a grout bag, similar to a cake decorating bag to apply the mortar. Squeeze in the mortar, the same mix used to install the stone, minus the portland, and allow to dry a few minutes. When the mortar can be raked out with your finger it is ready to be tooled. I use a wire brush to do this. Basically, you are detailing the stone. I like to scratch out about 1/2 to 3/4 inch.
Clean up is easy. Take a heavy bristle brush and go over the stone to remove mortar stains.