Precast or in-situ concrete benchtops can have a range of effects: raw or highly finished; natural greys, tinted or integrally coloured; surface patterned, stamped, acid–etched or crazed; sand/glass blasted; or with exposed polished aggregates. There is no limit to what you can create with this versatile material.
Concrete benchtops are a highly desirable commodity, because concrete can give warmth and a colour depth not available in granite or marble. Due to concrete’s versatility, it is one of the most extensively used building materials in the world, mainly because it can easily be formed into intricate shapes and is extremely durable.
Many homeowners are taking advantage of concrete’s flexibility and its capacity to integrate additional practical features such as sinks, draining boards, backsplashes and wet walls.
Concrete benchtop surfaces develop their own distinctive nature, depending on what the designer has specified and how the eventual user treats it. As the owner interacts with the benchtop the surface acquires its own character over time. Its unpredictability is part of its attraction. Texture and colour can vary, and regular use imparts a warm patina or shine to the surface.
Concrete benchtop contractors will offer their own standard or individualised colours. Samples can vary; due to each contractor’s own method for building the benchtops, and utilizing diverse types and amounts of cement and aggregates. There are also a wide range pigments, stains, and aggregate colours, so each concrete benchtop can be as individual as you like.
Check the Weight
The general rule of thumb for benchtops is about 50mm thick. A 50mm thick slab weighs approximately 120Kg/m². Floors and standard cabinetry should be checked for structural soundness before the benchtop is designed, but most cabinetry and floors should support the concrete slabs, as the weight of the benchtop is distributed over a large area.
How It Is Done?
Benchtops are either precast in a shop or built on site. Precast benchtops are poured in shops where conditions are easily controlled. They use special casting tables, which enable them to easily cure and seal the benchtop before relocating it to your home, most owners prefer this option as the kitchen or bathroom can be out of commission for some time. Precast benchtops will give a finished surface straight from the mould, only requiring a light sanding, polishing and coating with sealers.
Benchtops built on site can easily be formed to client’s specifications - radius edges, curved corners, etc. In-situ or concrete cast in place needs to be hand-trowelled, then left to cure for a week or so, prior to cutting, polishing and coating with sealers.
Whichever approach you prefer, you can always find a contractor who will do it for you.
What Is It Made Of?
Concrete benchtops are comprised of cement, aggregates, and a combination of admixtures. Other additives such as fibre reinforcement, silica fume pozzolan, and acrylic can be used as well.
Concrete benchtops can sometimes develop hairline cracks, but these tend to be non-structural and result from the natural shrinkage of the concrete. Your contractor should use reinforcement, which may help to prevent these cracks, which do not affect the durability of the concrete and should be considered part of the distinctive nature of your benchtop. The reinforcing used can be steel, wire mesh, fibreglass, and/or fibres. Depending on the benchtop, more than one type of reinforcement might be used.
Will It Stain?
Concrete benchtops should always be cured and then sealed. Your contractor will advise you on the sort of sealant, method of placement and number of coats that they need to apply.
The sealant is essential as it is water and stain resistant. If left in its natural state, concrete’s porous nature means it will stain. Staining can also occur if cuts or the heat of hot pans has damaged the sealant, though such an event is likely to damage other benchtop materials, as well. Your contractor can provide you with information on the sealers used and how to protect it.
How To Clean It
Clean it like you would any other benchtop with a mild, non-abrasive, non-ammoniated cleaner, your contractor will advise you on what to use.
Remember to always make sure that the contractor has references that vouch that they do the type of quality work you are looking for.