Applying the Stone
1) Lay out the stone
You will find it very helpful before you begin to lay out a quantity of stone (perhaps 4 sq metres or so) near to your work area to give you a selection to choose from. This will help to achieve a balance of shape, size, colour, thickness and texture as you work. It is good practise to mix stones from different boxes. Stand back and evaluate your work as you progress. Use of a 50mm x 50mm batten as a horizontal level is recommended.
2) Install corners first
Corner pieces have a long and short side which should be alternated in opposite directions on the wall corner. Fit corner pieces first and work inwards from the corners.
3) Fit flat stones
Stones should be applied with a uniform size of grout joint (12mm (1/2") or less is desirable). Long, straight or unbroken joint lines should be avoided.
Using the masons trowel, "butter" the back of the stone with a 12mm (1/2") even layer of mortar. Press the stone firmly into place on the prepared wall surface allowing the mortar to squeeze out around all edges. A gentle wiggling action whilst pressing will ensure a good bond.
If mortar accidentally spills onto the surface of a stone, do not rub off - wait until the mortar has set and brush off with a soft, dry brush (do not use a stiff or metal brush).
4) Trimming Stones
To achieve best fit, stones can be cut or shaped using a hatchet, wide mouth nippers or the edge of the masons trowel. Straight cuts can be made using a grinder or masonry saw. Apply stones with cut edges with cut edge turned away from view (up when above eye level and down when below eye level). Mortar can also be used when grouting to cover broken edges.
5) Filling Joints
Use a pointing gun to fill joints. Over fill rather than under fill to avoid pitting and to ensure all voids are filled.
6) Rake out the joints
When the mortar is firm to the touch (thumb print dry - usually 30 to 60 minutes) it is ready to be raked out by using a metal or wooden jointing tool. Rake out the excess mortar to the desired depth (don't rake too deep and compare joints to ensure consistency), whilst at the same time forcing the mortar into the joints in order to thoroughly seal the stone edges. Be careful not to rake the joints before the mortar is dry enough as smearing will occur.
7) Finishing the joints
Use a soft, dry brush to smooth the joints and clean away any loose mortar from the joints and stone face. Loose mortar and mortar spots which have set for only a few hours will clean easily - never allow them to set overnight.
Never use a wet brush or other wet cleaning material as this will cause the mortar to smear and stain.
Relevant information
Would you like to read more about our installation… download our installation guide.
© Viridian Stone
