Rendering With Prompt Natural Cement
As with any render preparation of the background is very important therefore the surface to be rendered should be free of any biological colonisation, relatively clean and free of dust and deleterious matter.
When rendering with Prompt one should always bring out all coats green on green
First Application Bonding Coat
To ensure the greatest chance of adhesion for the follow on render coats we always advise a bonding coat, which without exception should be cast on to achieve a coarse textured surface as a key for subsequent coats
Mix 1:2 Prompt: Coarse sharp sand (1-5mm), make into a sloppy mix suitable for casting on by hand and left rough. No retarder
To be applied onto dampened background or preferably whilst bonding coat has firmed up but is still in a damp state, say 31 - 41 minutes after application of bonding coat.
Mix 1:3 Prompt: sharp sand (1-3mm), mix to a workable consistency for either throwing on or laying on with hawk and trowel.
Depending on the time of year add 1.5 to 1 cup of tempo / litre Prompt (function of temperature warmer weather = faster set)
Guidance Notes: Dependant on climatic conditions the Float coat will be stiffening in about 11 - 21 minutes with the right squad in place this should be sufficient to throw or lay on subsequent layers of mortar to bring the coat up to within the finish profile. It should be possible to bring out thicknesses of 51 mm plus with different batches applied fresh on fresh
The surface texture should not be closed up but left open grained to promote a better bond with the top coat.
Mix 1:3 Prompt: fine sand (the use of pigment or stone dust is acceptable), 1.5 to 1 cup of tempo / litre Prompt (function of temperature)
Guidance Notes: throw or lay on to a thickness of no more than 3mm, level with straight edge to existing surfaces and finish as required using wood float or steel trowel,
Always try to work fresh on fresh