NHL Renders - Some recommended mixes
St Astier Natural Hydraulic Limes (NHL)

Background Prepare background Re-point and dub out as necessary with compatible mortar.	Stipple Coat Cast or sprayed on only Must be used on poor suction, dense / smooth surfaces. Leave as Cast Cure 2-4 days	First Coat Cast, spray or lay on. Well-keyed background. Control suction. Leave Keyed Cure 4-7 days	Second Coat Cast, spray or lay on. Control suction. Straightening coat. Leave keyed. Cure 7-10 days. Finishing coat in 2 coats work.	Finish Cast, spray or lay on.Control suctionFinish as required Cure min 3-10 days
Cob / Earth	Mix 1A - Sand SG3-5mm	Mix 1B - Sand SG10-15mm	Mix 1C - Sand SG5-10mm	Mix 1C - Sand SF / FS3-5mm
Wooden Lath		Mix 2B/3B - Sand SC12-15mm (8-10 cover)	Mix 2C - Sand SC8-10mm	Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm
Metal Lath		Mix 3B - Sand SC10-15mm (8-10 cover)	Mix 2B - Sand SM10-20mm	Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm
Soft Brick / StonePorous Blocks		Mix 1B - Sand SC10-15mmMix 2B - Sand SC10-15mm	Mix 1B/C - Sand SC/SM10-12mmMix 2B/C - Sand SC/SM10-12mm	Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm
Medium Brick / Stone / Blocks	Mix 2A/3B - Sand SG*3-5mm	Mix 2B/3C - Sand SC10-20mmMix 2B/3B - Sand SG**10-15mm	Mix 2C/3D Sand SC/SM8-12mmMix 2C/3C Sand SG**6-10mm	Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm
Dense Brick / Stone/ Blocks/ Concrete	Mix 2A/3A -Sand SG3-5mm	Mix 2B/3C - Sand SC10-20mmMix 2B/3B - Sand SG**10-15mm	Mix 2C/3D Sand SC/SM8-12mmMix 2C/3C Sand SG**6-10mm	Mix 1C - Sand SF3-5mmMix 2C - Sand SM5-8mm

* Stipple coat optional, depending on background suction and conditions.
** For harling applications.

Note: a wide variety of finishes can be achieved by adopting different binder and sand mixes to satisfy all requirements.

Coat thickness and optional mix ratios are related to exposure and background conditions and are the responsibility of the designer.

Curing and protection must follow best working practice.