The machine has the ability to utilise a variety of raw materials, the only prerequisite being that the substances are mouldable. Trials have been conducted on raw materials ranging from 100% clay through to mixes containing varying proportions of sand, loam and gravel. These tests indicate that the basic requirements for a successful mix is a proportion of clay combined with varying amounts of coarse particles with sufficient moisture to enable compaction and adhesion of the material under pressure.

Cement or other stabilising agents may be included in the mix to allow bonding of an otherwise unsuitable raw material or to create a stronger and more durable product.

The moisture content of the raw material can range between 6% and 15% depending on the type, or if any stabilising additives are used.

Some shrinkage of unstabilised bricks occurs over the first few days, the amount depending on the type of raw material, moisture content and weather conditions. It is generally, a good policy to let the bricks stand to allow any physical changes to take place before using them.

The most reliable method of determining a raw materials suitability is to simply make bricks from a particular sample and conduct tests on them as required.

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