Quick masonry


Surfacing of blocks

With Prompt natural cement, perform type or monitoring trials at the same speed as sulphur surfacing, with breakage possible within one hour. This solution is:

  • compliant with CERIB form 71 (March 2008)
  • non-polluting, without heat and odour inconveniences, recycling in special waste tanks or extraction hoods
  • twice as cheap as sulphur


  Dose in weight  Quantity to surface
1 side of 6 blocks
PNC 85 % 9180 gr
Dry sand < 1mm 15 % 1620 g
Tempo (setting retardant)* 0.7% of the cement mass 64 g
Water / 3210 g

* available from a building merchant


  • Dry-mix cement, dry sand and Tempo to homogenise the mix.
  • Add water and mix for 1 minute.
  • Setting time: around 10 minutes at 20°C, 20 minutes at 10°C and 5 minutes at 30°C

Follow CERIB instructions.

The block is compression-tested when mortar strength reaches the desired resistance in the block. Progression in strength of Prompt natural cement mortar: 1 hour: 12 MPa, 3 hours: 16 MPa

Precautionary measures:

  • do not remix after setting has begun
  • avoid excess water
  • keep sacks closed after use
  • during hot weather, work with cold water and sand stored away from sunlight