Tiled Balconies That Leak
There are often problems encountered with balconies that have ceramic tiled surfaces on a timber substrate.
Firstly the main cause is due to the tiles being inflexible, nearly impermeable, bedded on an adhesive, laid on a membrane, over a timber substrate and the tiles grouted with non-elastomeric material.
As timber is hydroscopic, movement occurs in the substrate notably with humidity and moisture that in turn produces stress in the ceramic tiles and grout. Consequences are often cracks to the tiles and also to the grout.
These cracks provide a passage for water to enter. The membrane is then called on to do its job which, providing there are no flaws in the material or its application at the time of construction will remove the water ingress via a drain into the stormwater system. This is providing that the balcony was constructed with a drain similar to that shown below. If not, what often occurs is that the water flows in the direction of the drain as a result of the falls built into the balcony; but the drain has only been designed and built to accommodate water from the top inlet and not between or below.
The pictures below show the result of water ingress into a balcony due to cracked tiles and an incorrect drainage fitting used. It should be stated that the drain balcony fitting shown above are a fairly recent innovation and were not generally available prior to 2000.
Photo showing the drain outlet from a leaking balcony, Terracotta tile, Membrane.
Balcony timber structure decaying as a result of the moisture ingress.
(note the membrane should be dressed down and into the drain outlet)
Balcony waste (plastic) cut to size and placed on top of the drain.
Badly fitting cover plate to receive a grill cover.
The issue of a requirement to apply and have granted a building consent to undertake any remedial work has and still is open to some interpretation.
If we are dealing with maintenance, and or repair of any component;
Schedule 1 of the NZ Building Act: exempted building work can apply:
- General repair, maintenance, and replacement
- The repair and maintenance of any component or assembly incorporated in or associated with a building, provided that comparable materials are used.
- Replacement of any component or assembly incorporated in or associated with a building, provided that: (a) a comparable component or assembly is used; and (b) the replacement is in the same position.
- However, sub-clauses (1) and (2) do not include the following building work:
(a) complete or substantial replacement of a specified system; or (b) complete or substantial replacement of any component or assembly contributing to the building’s structural behaviour or fire-safety properties; or (c) repair or replacement (other than maintenance) of any component or assembly that has failed to satisfy the provisions of the building code for durability,
for example, through a failure to comply with the external moisture requirements of the building code; or (d) sanitary plumbing or drainlaying under the Plumbers, Gasfitters, and Drainlayers Act 2006.
This exemption enables building owners to maintain their buildings, including carrying out any repairs or replacement, without having to get a building consent providing it fits the above criteria.
On the other hand if the work required to be undertaken does require a building consent and by so doing can’t meet the current NZ Building Code for one reason or another then an exemption can be applied for from Council: (refer to (b))
2Territorial and regional authority discretionary exemptions:
- Any building work in respect of which the territorial authority or regional authority considers that a building consent is not necessary for the purposes of this Act because the authority considers that—