1. Lithoplast
  2. Waterproofing of buildings
  3. Balcony and terrace insulation

Balcony and terrace insulation

Balconies and terraces are exposed to the rain as intensely as the roofs. Nevertheless, while every element of the roof is being solved by the constructor in the last detail, the balcony waterproof insulation is a far-reaching issue.

However, this will be a future problem. The balcony or terrace are subject to:

  • water,
  • humidity,
  • and UV radiation.

What to avoid

Another risk factor is the load. Whether the owner has a tomato pots on the terrace or even sets up a roof car park, the tile or other surface will push on the waterproofing layer placed below. To prevent the damage, carefully choose the entire structure.

Solutions for balcony waterproofing in practice

A suitable complement to the balcony waterproofing is a studded membrane. Thanks to its shaping, it forms a vaulted cavity between the waterproof insulation and the arched cavity tiles. This studded drainage membrane protects the waterproofing layer against mechanical damage caused by eventual utilizable load and reliably drains the water out of the balcony or terrace insulation. The air gap also speeds up the drying of balcony insulation and the tiles and thus improves the insulation safety of the total structure.

Recommended structure of the balcony or terrace waterproof insulation


  1. The bottom layer is formed with a perfectly flat, compact foundation of the balcony/terrace bearing structure without holes, protrusions, rubble or gravel residues. There must be a slope of 1-2%. The anchoring bars should be leveled eventually to avoid a barrier of water drainage. The goal is that there would be no places in the bottom layer where water would accumulate.
  2. This layer includes subbase iron-smoothed geotextile resistant against scrolling on anchoring screws. The subbase geotextile can be part of the insulating foil (IZOLTECH S 300).
  3. Welded waterproofing foil with perfect details is used afterwards. We recommend the FATRAFOL® 810/1.5 foil. PENEFOL 800/1.5 is a conditionally usable membrane for small structures; this membrane must be integrated and concealed in the structure.
  4. The next layer is LITHOPLAST® PERFOR 10/0.8 studded membrane. Butyl-rubber double-sided ribbon in a 40/40 cm mesh and a single-sided adhesive butyl rubber band with a width of 40 mm assures it against displacement in the "studs".
  5. All the details on balcony/terrace insulation are performed using a plastic covered anchored bar used for welding the waterproofing membrane. 6. Terrace surface finish with bearing layer of concrete screed or gravel applied directly into a studded membrane.