APPENDIX A
SPECIFICATION
SPECIFICATION
Plaster:
Generally new internal plastering to masonry walls and repairs to existing plaster on masonry
shall be in three coat work to the following specification:
Scratch Coat: 1 part non-hydraulic mature lime putty (thick consistency) to 3 parts, sharp, well
graded sand, with the addition of 2kg of horse or goat hair per tonne of plaster.
Floating Coat: 1 part non-hydraulic mature lime putty (thick consistency) to 3 parts, sharp, well
graded sand, with the addition of 2kg of finer goat hair per tonne of plaster.
Setting Coat: 1 part non-hydraulic mature lime putty (thick consistency) to 1 or 2 parts kiln
dried, sieved silver sand, depending on the finish required.
Limewash:
1 part non-hydraulic mature lime putty added to 3 parts clean water, in a plastic dustbin with a
lid, and thoroughly mixed with a plasterer’s whisk attachment on an electric drill. The
limewash should be the consistency of semi-skimmed milk and when a clean steel trowel is
dipped into the mix it should form a definite line across the trowel but should still be translucent
against the grey steel. Colour with natural earth pigments.
Re-pointing Mortar:
1 part NHL 3.5 lime to 3 parts, sharp, well graded sand, coloured with natural earth pigments,
to suit the stone colour.
Limecrete Floors:
Compacted and levelled clay subsoil (blinded with sand to level, if necessary); breather
membrane (vapour permeable geotextile); 20-10mm Coated fired clay aggregate; breather
membrane (vapour permeable geotextile); 150mm limecrete (1 part NHL 5 lime to 3 parts
uncoated lightweight fired clay aggregate balls in a size of 0 – 20mm, mix to a porridgey
consistency); 65mm lime screed (1 part NHL 5 lime to 3 parts, sharp, well graded sand), screed
to be increased in thickness as necessary in areas where underfloor heating is to be installed.