HOURDEX a multi use binder

St Astier Natural Hydraulic Limes (NHL) 

For building mortars, renders stipple and base coats, roofing, chimneys, floor tiling.
Based on St. Astier natural hydraulic lime  with addition of OPC and additives for highly workable and breathable mortars.

  POWDER Test std. MORTAR (sand 0-3mm, Volume 1:3) Test std.
Dry Density 800 g.l.
BS459 1425g.l +/- 25g dry 
1650g.l +/- 50g wet
EN 1015-6
Whiteness 40.55 NFX08.012    
Workability (depending on water addition)     210mm +/- 10mm EN1015-3
Water retention     81% +/- 3% CSTB 2669-4
Compressive strength
24 hrs 
7 days 
28 days 
1.5 N.mm2

4-5 N.mm2
6-7 N.mm2

Thermal conductivity     0.540 W/m.K EN 1745
Vapour permeability     1,60.10-9kg/m2sPa (0.77g x m2 x h x mmHg) EN 1015-19
Elasticity moduli     7000 – 9000 MPa CSTB
Capillarity     0.75 g.min.  
Fire resistance     Class A1 (with silica or calcareous sands)  

Mortar preparation: Up to 5 minutes in conventional drum mixers.

Sand: Clean, well graded 0-3mm (general). Lower or higher granulometries can be adopted.
Avoid monogranular sands. Sands for renders base coats should not be below 0-2mm.

Adequately dampen materials or background if too dry or with high suction. Do not work in temperatures below 5oC or above 35oC. The building materials or background should not be frosty or too hot or water saturated. Protect fresh mortars from frost, rain or strong direct sun. Storage: in dry store. Reseal open bags a.s.a.p

Bricks, blocks, 1 bag (25kg) 85 litres 1 : 3 sand
Floor tiling 1 bag (25kg) 85 litres 1 : 3 sand
Roofing 1 bag (25kg) 70 litres 1 : 2.5 sand
Chimneys 1 bag (25kg) 65 litres 1 : 2.25 sand

Renders (base coat)
Manual application
Sprayed application

1 bag (25kg)
1 bag (25kg)
70 litres
60 litres (+/-10%)
1 : 2.5 sand
1 : 2 sand
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The above details are given for general information purposes and do not constitute a specification. For further Guidance, contact your St Astier Distributor.
Copyright © 2016 CESA, Chaux et Enduits de St Astier