Basic Facts and Things You Didn’t Know About Slate!

As slate experts and having created a huge range of products from slate since 1984, the team at Ardosia know a lot about our favourite friend. Here we are trying to provide you with some answers to questions about slate that we are asked on a regular basis. At Ardosia, we have answered thousands of questions about slate and they are never quite the same as each of our customers is different. Our slate questions and answers page tries to provide you with the basic details about slate but if you want more information, just ask as we are always happy to help.

 

graining of slate in a custom made sink

 

Is Slate porous or nonporous?

One of the primary benefits of slate is that it has very low porosity characteristics, hence its popularity for use on roof coverings and in wet areas. Thus slate is a very popular choice for use outdoors, from garden slabs , wall cappings and steps to barbecue kitchenss. It also makes a great choice for any floor or kitchen work surfaces, especially around sinks and it doesn’t stain as much as other materials.

 

Is slate more expensive than granite?

Slate tends to be less expensive than granite in the majority of cases. Slate is limited in colour where granite is available in a much larger range of colours, typically more expensive though. Granite is also a lot more porous than slate, it stains more easily and in some cases needs to be treated to prevent water intrusion and staining from liquids.

 

custom made vanity sink with slate polished grain showing

 

Is slate the same as soapstone?

Slate and soapstone are definitely different although some colours of soapstone make it look very much like slate. Soapstone contains talc that gives it a soft and soapy feel to the touch and like slate, is a popular material used for worktops and countertops. Soapstone is often softer than slate though and can mark, especially with cuts from a knife and can chip if something is dropped on it. Thus, slate is a more obvious choice for usage in  kitchens where a more durable finish is required.

 

Does slate break or split easily?

In production slate is split (along the cleavage) to achieve the thickness of material required and this is relatively easy to achieve. However, breaking the slate through the bedding  is very difficult and is normally achieved by ‘sawing’ the slab.  Hence, slate is great for tiles and cladding because it splits along the cleavage but has great strength through the bedding making it strong and thin, ideal for roofing where weight can be an important factor. Slate may not split perfectly along the cleavage and may need a finish to generate a surface suitable for a worktop. It does split naturally along the cleavage to make it smooth enough for a roof or floor tile and when using a high quality slate smooth enough for a work surface.

 

smooth edged and finished kitchen worktop with graining

 

Is slate available in different colours?

Natural slate is typically grey in colour although there are many shades from very light grey to black, or even blue and green. The colour of the slate is determined by the area from which it originates but even within a quarry, slate can vary in colour. Traditional slate is most often grey whilst there are Welsh slates that are more blue in colour and used to roof many prestigious buildings such as Buckingham Palace.

 

Does slate absorb water?

Slate has a very low water absorption index making it almost completely  waterproof, one of the main reasons why slate is a preferred material for roof tiles, cladding and tiles in wet-rooms as well as for countertops in kitchens. The slate then is very strong across one dimension and its structural strength leads to very low water absorption.

 

Is slate a good insulator?

Slate is a good electrical insulator making it a great choice for roofing. Slate is not a particularly good thermal insulator but it can be split in very thin forms making it light in comparison with other natural materials. Again, this is one reason why slate is a popular choice for tiles and why we typically have roofing insulation under the slate. Slate resists heat, one of the reasons that it is a popular material for fire hearths or for kitchen work surfaces, where it can withstand the heat of hot pans.  This also makes it great in the kitchen for splash backs around high temperature ovens and hobs.