Waterproofing Wet Areas: Bathrooms, Balconies and Terraces

Bituminous coatings are used under tiles and screeds in some regions.

Tips

• Use primers for adhesion
• Apply in two coats
• Reinforce at corners with fabric
• Test with flooding before tiling

Gilsonite-modified coatings improve water resistance and hardness.

Typical areas

Showers, bathroom floors, balconies, terraces and planters – anywhere water stands or splashes regularly.

Bituminous vs. cementitious systems

Bituminous coatings are very water-resistant and economical. Cementitious and polymer membranes are often preferred under tiles because of tile adhesive compatibility. Check the tile adhesive supplier’s recommendations before choosing a bituminous system.

Key details

• Slope screeds toward drains.
• Use pre-formed corner pieces or fabric at wall–floor junctions.
• Seal around drains with compatible collars.
• Carry the waterproofing up walls at least 15 cm, higher in showers.

Flood test

Block drains and fill the area with water for 24–48 hours before tiling. Any leak is far easier to fix at this stage.

See waterproofing grade gilsonite.