Artificial stone wall cladding also called wall veneer can be installed with a limited knowledge of masonry work methods and procedures. When you are applying stone over brick or new or painted concrete or concrete block, metal lath should be applied first to ensure that you have a good bond.
When applying over wooden or steel walls a weather resistant barrier should be applied under the metal lath.
Step (1) Preparing the Wall for Artificial Stone.
Due to the comparatively light weight of artificial stone no special foundations or structural work needs to be done. The stone veneer can be applied to any structurally sound surface.
Brick or Concrete Walls :
To provide a good bonding surface galvanized metal lath should first be applied to the wall surface using galvanized concrete fasteners.
Wood or Metal Walls:
On exterior applications a moisture resistant barrier should be applied first before the metal lath. The lath should be attached with galvanized nails or staples on 400mm centres and 150mm apart.
Please Note: At the discretion of the builder it is common practice overseas not to use lath on sound interior walls merely applying a scratch coat.
Step (2) Applying the Scratch Coat :
In most cases the metal lath is covered with a thin scratch coat of mortar to provide a good rough surface. This allows easy adhesion of the artificial stone to the wall. The mortar used to make the scratch coat should be workable-not too wet or too dry in consistency. Allow the scratch coat to dry overnight before proceeding with the application of the stones.
Step (3) Applying the Stone:
Be methodical in your work practices. Clean the backs of stones with a bristle brush and set out close to the job site so you can review the final appearance by mixing different size shapes.
Apply a 25mm thick layer of mortar on the back of the stone and press it firmly onto the wall surface with enough pressure to squeeze out a little mortar on all sides. Apply with a wiggling action to ensure a good adhesion with the scratch coat.
In hot weather you may need to dampen the scratch coat before applying the stones as moisture may be drawn too quickly from the mortar. Bunnings have recently imported an American mortar brush that is useful to flick water onto the job in small amounts.
The best way to start applying the stones is to work from the top and work down. This keeps the work surface clean. If corners are necessary, apply these first, as this assists alignment of the whole job. Keep the mortar joints between the stones as tight as possible as this improves the appearance.
Step (4) Trimming and Grouting the Stones:
If necessary the stones may be cut and shaped to fit. You can use a hatchet, trowel or nippers. Try and work the cut stones into the pattern so that the raw, cut edges do not show.
After you have finished applying the stone, fill a grout bay with mortar, which may be coloured if required and partially fill the joints between each of the stones. The grout may be used to cover any irregularities in your work such as cut edges. Avoid getting the grout on the stone surfaces.
Step (5) Cleaning:
After the mortar joints have become firm rake out any excess mortar with a wooden stick or joining tool to point up the joints and generally smooth out the work. Generally compact and seal edges around the stones.
Use a whisk broom or soft faux finish brush to clean up any mortar that may have fallen on the face of the stone. Do this cleanup work before the mortar has commenced to set.
Step (6) Sealing:
Sealing indoors is not essential and may or may not be necessary depending on the finished look you require. Sealers for exterior work are listed separately on our web site.