Mapei Primer G is a water-based synthetic resin primer for preparing absorbent building surfaces before compatible tile adhesives and floor levelling compounds. It is particularly useful on gypsum plaster and anhydrite, where directly applying a cementitious product without appropriate preparation can compromise the finished system.
On suitable gypsum plaster, anhydrite screeds and other approved absorbent substrates, Primer G helps regulate surface absorption and prepares the base for the next compatible layer. This makes it a practical choice during tiling and floor preparation where different materials need to work together.
Primer G is aimed at absorbent surfaces, especially gypsum-based materials. For an internal renovation floor combining absorbent and non-absorbent areas, Eco Prim T Plus may be more appropriate; for a textured bonding key on suitable existing tiles, compare Eco Prim Grip.
Imagine preparing a renovated bathroom with gypsum plaster on the walls or an anhydrite floor that must receive a compatible cement-based tiling system. The surface may look ready, but its absorbency and chemistry matter to the layer applied over it. Primer G prepares that absorbent base, helping the installer establish a more reliable starting point rather than treating gypsum like ordinary concrete.
It is also useful when a floor or wall absorbs moisture unevenly and the next finish needs controlled suction. The advantage is straightforward: better preparation before the more expensive adhesive, leveller and tiles go down. Specify the dilution and drying to match the actual surface rather than applying one blanket method across the job.
Clean, sound surfaces are essential. Dilution and drying depend on substrate porosity and the subsequent Mapei system. Primer G is not a damp-proof membrane or waterproofing product.
What is MAPEI Primer G used for?
It primes porous internal substrates such as gypsum and anhydrite before compatible adhesives and levelling products.
What consumption should I allow?
About 0.1–0.2kg/m² depending on the application.
What drying time does the current Australian page state?
A minimum of 2 hours.
Is Primer G a waterproofing membrane?
No. It regulates absorption and prepares porous substrates.
| Property | Value |
|---|---|
| Consistency | liquid |
| Density | 1.01 g/cm³ |
| pH | 8 |
| Solid Content | 18 % |
| Maximum VOC (2004/42/EC) | 0 g/l |
| Application Temperature | 5°C to 35°C |
| Drying Time Before Levelling Compounds or Adhesive (Concrete) | 30 min |
| Drying Time Before Levelling Compounds or Adhesive (Gypsum) | 30-60 min |
| Coverage Rate | 0.08 - 0.15 kg/m² |
Here are some common examples on where Mapei Primer G used by our customers.
