Concrete – Preparing The Base

It seems to me that many people think that a concrete driveway or path will cover any number of shortcuts and other sins.

Well if you want a good finish, that will last, you need to make sure that preparation isn’t skimped.

Without a good base for the slab to sit on cracks will soon spoil the finished look of your drive or path.

This is what I would regard as the minimum preparation for laying a concrete driveway or path for a new home.

Well prepared base for concrete path.
  1. The area of excavation, and base, should be a minimum of the area of concrete plus 150 mm all round, except where the edge is against a wall.
  2. During dry weather excavate the area to a depth that will allow for the depth of the slab plus for a gravel base of at least 100mm.
  3. Check the excavated surface for soft areas. Typical soft areas can be; water logged, topsoil, and badly backfilled trenches.
  4. Excavate any soft areas and backfill with gravel well compacted in 100mm layers.
  5. Lay the gravel base to the required level making sure its well compacted, preferably with a vibrating plate compactor.
  6. Keep people and equipment off the area and make sure surface water is not allowed to flow across the area.
  7. Cover with a polythene layer. You can normally buy this off a roll by the m at a building suppliers for small jobs.

 

For more posts on on getting your paths and driveways correct see Concreting

Liquid Limestone

You might have heard of Liquid Limestone as an alternative paving material…….But what is it?

Really its just a different type of concrete.

It is much more common in West Australia than other states.

The differences between conventional concrete and Liquid Limestone are:

  • Instead of standard Portland ‘Grey’ Cement it uses White Cement.
  • It uses crushed limestone rather than other types of rock gravel and sand.
  • Quite often a plasticiser is added. This means the mixture can be poured without having to add too much water.

Various patterns can be applied to the surface as the concrete sets. (see above photo)

As well as the standard limestone appearance the supplier can add various pigments. If you want a strong colour I think you would be better off  just going for coloured concrete.

Because it can be laid in large slabs like concrete there are less joints than in conventional brick or concrete slab paving. (There will still need to be some joints. For joint spacing see: Concrete Joints 1)

With the lighter colour it can be cooler underfoot than other pavements.

To maintain its appearance liquid limestone will need to be sealed around a week after laying.

Thanks to Concept Concrete WA. for these two great examples of  Liquid Limestone Paving

For  posts on on getting your paths and driveways correct see Concreting