BALCONY WATERPROOFING REPAIRS

Leaking Balconies – Getting It Right – Do It Once

Leaking balconies, roof & rooftop terraces

  • Can cause catastrophic damage to structures below.
  • Water leaks may cause not only aesthetic
  • superficial damage but can progress to affect the structural integrity of the building envelope itself.
  • If a failed waterproofing membrane is the reason for the water leaks, then re-grouting or surface sealing is not the way to repair or restore a balcony.
  • This is a band-aid method which may stop or slow down water leaks temporarily. However, when the balcony moves, the tiles, grout & membrane will crack & leaks will start again.
  • In many cases, when membranes that have failed, the balcony will require a complete stripped off, structural works if needed, waterproofing re-installed & finish surface.

Items to Consider

  • Strength of subfloor and screed.
  • Presence of substrate dips and hollows.
  • Balcony design i.e., correct balcony slope, fall.
  • Window / door frame installation.
  • Door Threshold sealing.
  • Adequate drainage.
  • Possibility pipes leaking underneath.
  • Existing tiling & expansion joints – if tiling affecting balcony failure i.e., adequate number.

Waterproofing Preparation

  • This is a critical aspect of any waterproofing membrane installation.
  • Substrate must be clean of dirt and other contaminants.
  • Surfaces prepared, including vacuum cleaning and / or diamond grinding as necessary to leave surface smooth, dry, clean and free of all debris.
  • Substrate may need to be washed.

Waterproofing Detailing

  • Before installing a waterproofing system, construction features which represent discontinuity in the membrane layer must be adequately protected & sealed.

Perimeter Upturns

  • Attachment points for railings, balustrades.
  • Joints between horizontal and vertical surfaces.
  • Structural and expansion joints. Install sealant 15mm wide to all junctions and tool off smooth.
  • Reinforce with polyester or fibreglass mat all upturns to a DFT of 1.2mm 100mm above finished floor height or 25mm above water line.
  • Make sure membrane system has been installed 200mm onto balcony floor areas.

Door/Window Step Downs

  • Install sealant 15 mm wide to all junctions and tool off smooth.
  • Reinforce with polyester or 225gsm fiberglass mat to all set downs to a DFT of 1.2mm making sure the membrane system has been installed 200mm onto balcony areas.

Drains & Floor Waste Detail

  • All floor wastes shall have a recessed leak control flange installed.
  • Prime flange with appropriate primer and allows primer to cure.
  • Install membrane system as below and clip flange over membrane when cured.

Drain & Floor Waste Detail

  • All floor wastes shall have a recessed leak control flange installed.
  • Prime flange with appropriate primer and allows primer to cure.
  • Install membrane system as below and clip flange over membrane cured.

Waterproofing Installation

Australian Standards

Installation method of a class 2/3 waterproof membrane system to external concrete in accordance to A4654.2.

Installation Conditions

  • Waterproofing Systems should not be installed in either hot or cold temperatures i.e under 10°C or over 35°C.
  • Surface temperatures will present problems to accelerated and decelerated cure times.
  • Waterproofing membrane.

Type of Membrane

  • Flexible waterproofing membrane withstand normal cyclic fluctuations.
  • Able to withstand ponding water.

Tiling

  • Balcony floors are exposed to direct sunlight and, therefore, to very large temperature variations between day and night-time.
  • These variations create formation of strains due to different thermal expansion and contraction of the substrate and finished surface.
  • It is critical the tiles and laid with joint sufficiently large to absorb thermal movement.
  • Adhesive chosen to bond is fundamental.

 

Paul Evans
Manager / Director
Findlay-Evans Waterproofing