Water & sanitation
Repair and waterproofing of basins, washhouses, reservoirs and canals
Overview
Repairing and waterproofing a basin
The restoration of basins, washhouses and hydraulic structures requires materials capable of ensuring long-term watertightness, durability in permanently wet environments, and compatibility with existing substrates.
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Solution
When used as a mortar, PROMPT natural cement is ideally suited for carrying out repairs on masonry substrates (stone, brick) or on old concrete, whether Portland cement-based or natural cement-based. It can also be used for waterproofing and jointing in masonry structures.
Technical
Before carrying out repairs, it is essential to prepare the substrates.
On concrete substrates, cracks must be identified (these are easily visible after spraying and as the surface begins to dry). They must be widened, if necessary, and cleared of all loose material before being cleaned.
On masonry substrates, the joints must be thoroughly cleaned. They must be cleared of all loose material and free of moss, lichen and roots.
Whatever the substrate, it must be thoroughly wetted so that it is damp but not dripping before carrying out the repair.
Prepare a mortar using one part PROMPT natural cement to one part sand. Mix thoroughly, then add water until a workable consistency is achieved. Apply the mortar using a trowel or a spray pot. Press firmly to ensure good adhesion.
To finish, grout the masonry joints with PROMPT natural cement mortar mixed in the same proportions. To grout non-submerged areas, the mortar may be mixed with hydraulic lime. Remove any excess mortar and clean the stones immediately to prevent staining. Between two walls made of different materials, such as concrete and stone, a joint filler can be applied before applying the mortar.
On walls that are permanently submerged, apply a PROMPT natural cement-based render as a waterproofing measure.
Re-submerge within 24 hours. The non-submerged sections must be left to cure for at least 24 hours.
Technical Characteristics
Natural PROMPT cement is a rapid-setting hydraulic binder designed for use in demanding environments:
- Rapid setting and early strength development
- Excellent adhesion to mineral substrates (concrete, masonry, stone)
- Low shrinkage, reducing the risk of cracking
- High resistance to moisture, immersion and aggressive waters
- Compatible with marine and hydraulic engineering standards
These properties ensure reliable performance for both structural repairs and waterproof rendering systems.
Benefits of Use
Repairing and waterproofing with PROMPT natural cement mortar is the solution:
- Quick: very short time before the water can be used again
- Aesthetic: its colour closely matches that of stone
- Natural: safe for aquatic life
Tips
To repair surfaces where water is running down or where there is water under pressure, apply a first coat of PROMPT natural cement mortar or pure paste over the entire surface. This will instantly seal any micro-cracks. Cracks through which water is leaking must be treated as described in the information sheet: Stopping water ingress.
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Product
Everything you need to know about PROMPT natural cement
As the only cement that develops strength immediately upon setting, it enables the fastest possible return to service. In its formulation, it also acts as a powerful accelerator for all hydraulic binders (lime, cement, cement-sand, cement-ash).