QSE Builders are registered builders who also specialize in the repair and replacement of outdoor balconies within 25KM of Melbourne CBD. We offer a 10 year guarantee on water tightness of balcony after works, issued by our licensed Waterproofer
Balconies that leak water into rooms or spaces below is one of the most frustrating things a home owner can experience.
Most of the issues are due to poor attention to detail, especially flashings and design at doorways and windows. Despite the expensive nature and difficulty of repair works to or replacement of balconies and even if the builder adheres to the Australian Standard for Waterproofing Membrane Systems for Exterior Use (Outdoor Balconies) AS 4654.2 (2009), this is still not enough. Balconies are built to the design provided and unless the builder or architect personally takes an interest in and attends to best practice, the balcony will in a short time will start to fail.
The Building Commissions Guide to Standards and Tolerances still states that you can use "particle board referred to in AS 1684.2 (2006)-Installation of particleboard flooring"on external balconies, despite this not being allowed under AS 4654.2 (2009) which adds to the confusion from Builders and designers alike. This doesn't change the fact that many balconies were built with chipboard up to 2009.
In the "olden days", most timber framed balconies had a physical barrier of tin or copper put over the floor joists below and then flashed deck supports to this tin with a timber deck above. Any water fell through the deck, onto the deck below and drain to gutter or to another roof below. No chemical barriers involved.
The Australian Standard does not demand upstand flashings at doors, window or walls which we still find astounding. It simple asks for the membrane to return up walls or sills, even drawing the membrane as if it
is sheeting. Considering 99% of domestic balconies are waterproofed with a liquid membrane, you are relying on a dried film not to crack in corners. This is the #1 failure we see onsite and it always happens at the opening at doorways or windows or at the floor/wall intersection, especially if the balcony has internal drains and cannot drain off the edge.
Water will always get through the grout. It is vital that this sub-tile water can drain on top of the membrane and flow to a drain or off the edge. If it can pool between the tiles and membrane, it can be pumped up walls, past flashings into ceiling below. It also causes effloresces in the grout above.
There are lots of companies who will reapply grout, apply topical waterproofing solution to areas and re-apply caulking to tiles. It is not unusual that some customers have tried these cheaper solutions before realizing that major repairs are required and essentially have wasted their money. Generally, a balcony that is timber framed (built on timber joists and a substrate) will require the replacement of substrate, repair of joists/ceiling below and a new surface on the deck. Typical costs to remove tiles and substrate, repair joists and guttering, new cement sheet based substrate, upstand flashing , membrane and application of trafficable membrane is between $8,000.00 to $14,000.00 for a mid-sized balcony.