Limecrete

Surface Preparation
The area to be concreted with limecrete should be clean of top soil and vegetable matter. A hardcore base of clean hardcore (minimum depth 150mm) should be well compacted down by use of a vibrating plate. A limecrete floor requires no D.P.M. as the lime method is to allow moisture to breath through a structure.

Laying the Limecrete
Limecrete is laid in a single layer of 50mm or can be laid at a greater thickness of 100mm by laying 2 x 50mm layers. These 2 layers should be laid onto one another while the lower layer is still green (no longer than 12 hours between layers)

Mixing
Limecrete should be mixed to the consistency of a floor screed i.e., a semi-dry state, which will hold together when squeezed by hand, wet traditional concrete type mixes will result in excessive shrinkage. If possible a screed mixer or roller pan mill should be used and drum cement mixers tend to result in the mix balling

Finishes
Simple limecrete over- sites can be felt finished by tamping with a wooden or steel tamper and lightly tightened with a timber or polyurethane float or working with a vibrating plate. Fine surface should be screeded and tamped in a float screeding manor and then scoured with the float and trowelled.

Aftercare
Once laid limecrete should be kept damp for 96 hours (minimum). This may call for spraying with water during warm and hot periods. Limecrete must always be protected from freezing conditions for the first 10 days after laying. Traffic should be avoided for 10 days, and thereafter-protective boards should cover the work for 3 weeks before exposure to general traffic.

Mixes
1 Part NHL5
2 Parts blended aggregate – 33% Washed Sharp Sand
66% Aggregate 10-18mm