Ceresit CT17 - Deep penetrating primer-10L
What is Ceresit CT17?
Ceresit CT17 is a solvent-free, deep-penetrating primer designed to strengthen and stabilize porous or "dusty" surfaces before tiling, floor leveling, or rendering. It works by soaking deep into the substrate to reduce absorbency and improve the bond of subsequent layers like adhesives or CT16 primers.
| Technical Specification | Value / Detail |
|---|---|
| Material Base | Synthetic resins (Solvent-free) |
| Application Method | Brush, roller, or spray |
| Average Coverage | 0.1 to 0.5 L/m² (depending on substrate porosity) |
| Drying Time | Approx. 2 to 4 hours |
| Color | Light Yellow (to identify treated areas) |
| Substrate Type | Plasterboard, aerated concrete, screeds, gypsum |
| Indoor/Outdoor | Suitable for both internal and external use |
- When should I use Ceresit CT17 instead of CT16?
Use CT17 first if your wall is "chalky," dusty, or highly absorbent (like old brick or aerated concrete). CT17 strengthens the wall from the inside, whereas Ceresit CT16 creates a surface "grip" for the final render. - Why is Ceresit CT17 yellow?
The light yellow tint is a deliberate feature. It allows you to see exactly which parts of the wall have been treated, ensuring no patches are missed, which is critical for consistent surface strength. - Can CT17 be used on floors?
Yes. CT17 is excellent for priming floor screeds and concrete slabs before applying self-leveling compounds or tile adhesives to prevent air bubbles and improve the bond.
- Surface Prep: Clean the substrate of any loose debris, oil, or grease.
- Application: Apply CT17 liberally using a brush or roller. For very porous surfaces, two coats may be necessary.
- Cross-Check: Look for the yellow tint to ensure the entire area is covered evenly.
- Drying: Allow it to dry for 2–4 hours. Once dry, the surface should be scratch-resistant.
- Next Step: Apply your Ceresit CT16 Primer or Tile Adhesive once the CT17 is fully cured.
- Pro-Tip for Porous Walls: On highly absorbent surfaces like aerated concrete (thermal blocks), dilute the first coat of CT17 with water (1:1 ratio) to help it soak deeper, then apply a second coat undiluted.
- Pro-Tip for Speed: CT17 is "solvent-free," making it safe for use in poorly ventilated indoor areas without needing heavy respiratory protection.
CERESIT® CT 17 is a solvent-free universal primer for absorbent substrates (walls, floors, ceilings) indoor and outdoor prior to fixing ceramic tiles, pouring floors, fixing floor lining, papering, puttying, painting, or fixing thermal insulation boards. Substrates primed with CT 17 are of lower absorbency, which prevents too rapid over drying of adhesive mortars, flooring, putties and paints.
Available canister size: 5L, 10L