Technical Reference

Treatment Procedures.

Step-by-step waterproofing, structural repair and rehabilitation methods, grouped by the chemistry they use, each mapped to the Armstrong products that carry it out. Select a treatment to view the full procedure and product recommendations.

Choose a treatment

Treatment · Cementitious & crystalline

Cementitious Waterproofing

Acrylic polymer elastomeric cementitious coating system

Applications

Roof slabsTerracesSloped roofsWater tanks and sumpsBasementsMasonry wallsBathrooms and toilets

Procedure

Clean the surface thoroughly, removing dirt, dust, loose plaster and other contaminants. Chip off loose mortar and cement lumps and wire-brush the surface.
If tar or bitumen felt was previously applied, remove it completely, including the contaminated layer.
Dampen the surface so the pores are full, with no water standing on it.
Apply a primer coat of ROOFCOAT FLEXI 100 mixed 1:2 with cement and about 500 ml of water.
Where the surface is cracked or holds water, bed geo-fabric into the wet coat, overlapping the strips.
Apply two coats of ROOFCOAT FLEXI 100 mixed 1 litre to 2 kg of cement and about 200 to 250 ml of water, each coat at right angles to the last, 3 to 4 hours apart. ROOFBOND RFX PLUS 210 is mixed from its 5.1 kg of liquid and 15 kg of powder and applied the same way.
On a new building, apply the treatment on the mother slab and lay the cement screed over the second coat while it is still damp.

Important Suggestions

Surface preparation decides the result. The substrate must be free from dirt, dust, laitance, loose particles and grease. Take the coating up the walls at every floor-to-wall junction.

Why This Treatment?

The polymer cementitious coating forms a tough, elastic, jointless membrane with 120%+ elongation that bonds to damp concrete. It suits surfaces that stay damp or sit in water, takes a screed or tile bed over it, and survives cleaning inside tanks.

Recommended Products

ROOFCOAT FLEXI 100

Acrylic polymer modified elastomeric liquid mixed with cement into a brushable, flexible waterproof coat. Non-toxic, suitable for drinking-water structures.

ROOFBOND RFX PLUS 210

Two-part flexible cementitious coating. No penetration at a 50 m water head, bridges cracks up to 3.5 mm.

Dosage & Coverage

ROOFCOAT FLEXI 1001 litre + 2 kg cement + about 200 ml water

Coverage20 to 30 sq.ft per litre for two coats

ROOFBOND RFX PLUS 21013 to 14 sq.m per 20.1 kg unit