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ARCHITECTURE: SELF BUILDING
Materials Sourcebook: Concrete
Image: Cast Advanced Concretes
Choosing concrete will give your home a contemporary edge, but what are the implications, from an eco-friendly point of view, and will it look good forever?
Until fairly recently, the word ‘concrete’ conjured up images of faceless office blocks and graffiti-covered car parks, but now it’s become the material of choice in some of most fashionable homes around. There are several reasons for this. As minimalism crept in, architects and designers woke up to the fact that concrete’s utilitarian, understated looks complemented the pared-down interiors perfectly. New technology means that it can be made and installed in domestic as well as large-scale projects, and it is now available in a range of exciting finishes and textures.
Hard Facts Concrete is a dense material made from a mix of sand, water, gravel and Portland cement. It is cheap, strong, versatile, fireproof and virtually indestructible, and resistant to moisture and invasion by insects.
However, it needs to be sealed with an epoxy or acrylic resin, as it is porous, stains easily and produces fine particles of dust if left exposed. It is also hard and noisy, something to bear in mind if you have young children. Shades vary from white through to dark grey, though dyes can be added for colour, or surfaces can be painted using special concrete paints.
Types Of Concrete Depending on the application you’re after, concrete can either be cast in situ – mixed and laid on site, or pre-cast - made off-site. Mixing and installing concrete is a highly specialised skill, so you should always leave it to the professionals.
Concrete cast in situ is usually used to create foundations and floors, but is also used for baths, sinks and worktops. However, whereas previously it was only used for subfloors, poured concrete is an increasingly popular finish in its own right, though it does need to rest on a strong, level concrete base. The process can be messy and there needs to be space in which to work. And remember that you won’t be able to use the area until the concrete has set – which can be up to 24 hours - and it will take another few weeks to harden (or cure) fully.
Pre-cast concrete is used to make tiles, wall panels, worktops and slabs, but its most common application is to produce breeze blocks, which are widely used in construction. Pre-cast concrete has benefited greatly from advances in technology, as intricate patterns can be created using digital imaging. Installation of tiles, for instance, is less disruptive than casting the concrete in situ, as you don’t have to wait for it to cure. Tiles come in a variety of sizes and finishes, and can be fitted on floors and walls, though as with a poured concrete floor, the subfloor needs to be even and able to take their weight. Thicker slabs are suitable for exterior paving.
