Choosing stone

When deciding what stone to use for your project it is important to remember that for as many possibilities various stone types have, they all have different properties and therefore have their limitations. A certain colour variant may be governed by a certain method of building/cladding according to the type of stone used. We will gladly assist from the early conceptual stages right through to the completed product.

At elEM, our approach to our work is done with pride and doing the job correctly, without compromising on quality. As our clients and future clients are important to us, we have compiled a list of often asked questions and provided answers to guide you through the process of stone building and cladding. Should you question not be answered here, please email us your request and we will gladly answer it and try to assist you where necessary.

Q. How do I estimate the amount of stone that I will require for stone cladding

You start by measuring the length of the wall, times the height of the wall, to calculate the square meterage measured in millimetres. Always remember, when measuring around an outward facing corner, add on 300mm for the thickness of the stone cladding (approximately 150mm in depth). The height is calculated from the footing that the stonework starts on, to the top.

fig.1. how to calculate cladding area

Q. What is the ideal thickness of cladding from existing surface to the face of the stone?

The ideal thickness is roughly 150mm from the exsting wall surface to the face of the stone. However, the minimum would be 120mm on most applications. This is a general rule, and it is always better to have your architect and engineer approve this before going ahead with certain cladding work.

Q. What is the difference between dressed stone and semi dressed stone?

Semi dressed stone is stone that is purchased as it comes from the quarry. It is roughly geometric. The stonemason starts with semi dressed stone and dresses it (piece by piece the stonemason will chisel away at each stone to create the desired shape) to prepare it for building into the wall surface.

fig.2. dressing of semi dressed stone

Q. How do I determine how much wastage to allow for when purchasing stone?

Since stone is a natural product and somewhat irregluar in shape, a certain amount of wastage will accumulate as the stone is dressed by the stonemason. Geometric dressing creates a high amount of wastage, but this can vary depending on how skilled the stonemason is. The quality of the stone may also affect the wastage factor (more hairline fractures = more cracking and more broken stones).
Please refer to our chart as a rough guide for wastage when using our stone.
Other factors that cause wastage are transit losses and on-site breakages. It is therefore always important to check whether you have been quoted for wastage when shopping for a stonework contractor - a cheap stonework contractor or stonemason may end up becoming a very costly exercise! This can be avoided if you have done your homework...

Q. Does elEM charge extra on wastage?

When purchasing stone only, elEM charges you only for the stone you order. From here we advise on how much extra to purchase for wastage. Different stone has different wastage considerations.
When elEM is contracted to supply and install, then wastage is already worked into the square metre/ton rate that you pay. Wastage therefore becomes elEM's responsibility without the surprise cost to you later.

Further reading and Stone Resources