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TT - Bathroom Application Guide

Installation Guide / Wet Rooms Topciment: Application Tips for Bathrooms. Industry guidance for preparation, drying times, and step-by-step application in wet rooms.. 🛑 IMPORTANT: Always make a physi…

tomas martinsson
Updated by tomas martinsson
Installation Guide / Wet Rooms

Topciment: Application Tips for Bathrooms

Industry guidance for preparation, drying times, and step-by-step application in wet rooms.

🛑 IMPORTANT: Always make a physical color sample! NEVER start a bathroom without presenting a physical sample of at least 60×60 cm in the correct color and texture. This saves time and prevents color shade disputes with the end client.

Pre-Start Checklist & Drying Out

• Inspection: Check falls/slopes and inspect for hollow voids under the tiles before starting work. The bathroom must be in sound structural condition.
• Cleaning: Have the client clean and degrease the bathroom a few days prior to arrival to remove soap scum and grease (grout lines must have time to dry).
• Drying Out: No showering in the bathroom for 3 days prior to start. Run underfloor heating for 1–2 days after the final shower, but turn it off completely 24 hours before applying cement. Use a dehumidifier/fan if underfloor heating is absent.
• Disassembly of Fixtures: Remove vanities, toilet bowls, etc. Obstacles in the workspace significantly prolong sanding and application times.
• Accelerating Drying: All layers except the final topcoat (topsealer) can be accelerated using standard circulation fans (never use heat guns/fan heaters). The topsealer must dry naturally from the inside out.

Substrate Selection & Preparation

🛡️ Are you only applying microcement on the floor?
When applying Topciment on tiled floors, or when setting a drain grate in tile adhesive, a moisture-barrier epoxy is always required to prevent subsurface moisture discoloration.
See full instructions for Primapox 100 Barrier here ↗

Microcement Application

1.
Priming and Reinforcement: Before starting with the microcement, ensure you have reviewed the substrate preparation guide for your specific surface above. Prime and mesh the surface according to the substrate type. • Cement-based repair mortar and tile adhesive: Prime the surface first with resin. Then embed the reinforcement mesh (50g or 58g) directly into a coat of Plus primer.
• Vinyl sheet: Embed the reinforcement mesh directly onto the prepared vinyl surface using Plus primer.
2.
Base Coat (Microbase): Apply Microbase in two coats. Ensure the mesh and first base coat on the floor are in place before applying the final wall coats for seamless corner transitions. Sand the entire surface thoroughly with 40-grit paper between coats and before applying Microdeck.
3.
Cleaning: Vacuum the surfaces extremely thoroughly and wipe down with a dry microfiber cloth before starting the topcoat. Dust creates scratches and causes material to dry prematurely.
4.
Topcoat (Finish Layer): Apply the decorative topcoat—either Microdeck (medium texture for floors/walls) or Microfino (fine texture for walls). Never touch up material that has started to dry, as this creates permanent color differences.
5.
Final Sanding: Sand the final decorative coat smooth using a random orbital sander or by hand. Sand cautiously around corners and edges to avoid sanding through to the base coat (which causes dark marks).
• Microdeck: Sand with 80-grit on machine (120-grit by hand).
• Microfino: Sand with 120-grit on machine (240-grit by hand).

Sealing & Topcoat Application

1.
Clean the surface carefully with a microfiber cloth (especially crucial on light colors to avoid dirty edges). Protect the surface from cords and tools, as untreated cement is extremely prone to scuff marks at this stage.
2.
Apply two coats of Presealer. Mask and protect the floor to avoid dripping onto unsealed surfaces (causes permanent spots). The second coat absorbs less and runs more easily—roll out drips immediately.
3.
Apply two coats of 2-component polyurethane sealer (TT Topsealer Dragon). Work the product into pores with firm pressure, then lighten up to level strokes. Cross-roll (vertically then horizontally) and finish strokes softly. Total recommended coverage is 0.15 l/m² across both coats for complete protection.
4.
Critical Step (Drain): Apply transparent wet-room silicone in the joint between the drain grate and microcement 3 days after sealing is complete. Also ensure the area between grate and waterproofing membrane is fully sealed with silicone or sealer if Primapox was not used as a primer. This prevents the underlying mortar from drawing in moisture, which causes permanent staining around the drain. *(Note: If only the floor was installed, do not seal here—Primapox must be used as primer).*

Drying Times & Post-Completion Care

• Silicone & Plumbing: Wait at least 3 days (preferably 5 days) before applying silicone and allowing plumbers to commence work. Any water spilled during installation must be wiped up immediately.
• Protective Covering: Do not cover the floor for the first 3 days. Afterward, protective paper may be used for a couple of hours at a time, but must be moved regularly. Leftover covering risks permanent color variations during curing.
• Usage: The bathroom and shower can be used no earlier than 5–7 days post-application.
• Furnishings & Cleaning: Rugs and solid objects may be placed after 14 days. Clean the surface with plain water only during the first two weeks.

Important Information for the Client

• Cleaning: Microcement must only be cleaned with pH-neutral cleaning agents. Acidic or strongly alkaline detergents damage the protective sealer.
• Squeegee: The client should always use a squeegee after each shower. Because microcement is seamless, standing water remains on the surface, which risks leaving limescale and water stains over time.
• No Bottles on the Floor: Shampoo bottles, soaps, and similar items must not be left standing directly on the microcement floor—use wall shelves. Water trapped under bottles can "suffocate" the breathable sealer, causing permanent marks.
• Future Maintenance: Inform the client that the shower area and floor will require a fresh coat of protective sealer in the future. Depending on shower frequency, this is typically needed after 2 to 5 years. Details are covered in the maintenance guide that must always be handed to the client.

Step-by-Step Guides (PDF)

Download or open complete technical guides for each substrate in PDF format:

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