Summary: Learn how to mix concrete, mix cement, the concrete mix for laying paving stones and patio slabs, the concrete mix for foundations for an extension, the concrete mix for foundations for garden walls, the general-purpose mortar mix for laying bricks and blocks.
Depending on the quantity required there are two ways of mixing concrete and mortar. You can either use a cement mixer which can be hired from a tool hire shop or you can mix up on a large board placed on the ground called a spot board.
Different jobs require different mixes and a selection of mixes with the ratio of ingredients is given below. Depending on the job you are doing you may need to include additional materials to give the mix a specific characteristic. These materials are lime, plasticiser, cement pigment, waterproofer and frost proofer. Some of these are quite self-explanatory, but they are all described in the materials section of this website under Cement, Aggregate and Sand.
Here we look at how to hand mix on a spot board.
The following mixes give the ratio of cement, lime, sand and coarse aggregate for different types of concrete and mortar mixes used in DIY. The proportion indicates the ratio by volume, usually a shovel-load. However, if greater accuracy is required in the mixing to maintain the strength or colour throughout then it is best to use a bucket to measure out the quantities. In some of the mixes below we have included lime, but you can replace this with a plasticiser if you prefer.
General-purpose mortar for laying bricks, blocks and pointing:
For laying paving stones and patio slabs:
Concrete for foundations for an extension:
Concrete foundations for garden walls:
General purpose concrete for a base for slabs or a garden shed:
Alternatively, another general-purpose concrete mix is:
Render mix for an undercoat for plaster or an exterior coating:
Author: C J Mills Google+
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