Extending the Life of a water tank
After many years of use, a water tank may
start to slowly leak. This can be from a number of reasons. A concrete
tank can gets cracks from small ground movements. A plastic tank may
split at the seams over time or from UV degradation. Your options for
repair will then depend on the type of tank you have.
Types of Tanks:
Concrete – a very solid
construction, requiring good ground preparation. Bushfire proof and the
only type of tank that can be placed in-ground. Concrete has a high
thermal mass, naturally keeping stored water cooler as well as
neutralizing acid in the water. Cooler water means much lower risk of
algae blooms and other bacteria forming. However can be prone to
cracking with ground movements. Tends to be the worst for overall
environmental impact.
Poly Tank – a lighter
more cost effective solution that is very popular in residential
situations. Tanks are made from polyethylene in a variety of colours
with minimal impact on the environment . The tanks are generally easy to
maintain and are 100% recyclable. Poly tanks are very strong, won’t
rust and less likely to crack than concrete tanks. Tanks come with a
minimum 10yr guarantee, but tend to use BPA and UV inhibitors in the
manufacturing process. Poly tanks also have a very low thermal mass, so
water will warm on hot days, which can be an issue with bacterial
growth.
Steel Modular Panel Tanks
– long life span (usually a 20yr warranty) and keeps water cool. Comes
in a range of styles and finishes, with a flat roof structure. Stainless
steel tanks can also be considered the best environmentally, with
almost 100% recyclability at end of life, but tends to be the most
expensive.
When fixing a tank, there are only a few methods that can be be considered:
Pros – inexpensive for concrete tanks if done properly and is some cases the water won’t need to be drained before application.
Cons – will not generally work on poly tanks, and needs to be flexible to accommodate tank movement.
Welding (plastic or steel)
Pros – This is an effective way to repair poly tanks, as done properly the weld is about as strong as the original plastic.
Cons – need to remove water to make repairs, and join strength is dependent on the skill of the operator.
Use of a tank liner
Pros – very flexible and
will move accommodate ground movements easily. Custom made to fit any
tank. Usually comes with a 10yr guarantee. Will fit any almost any tank
that is still structurally sound. Does not usually need the same level
of preparation as applied coatings do. Also if you can get inside the
tank, you can usually install the liner yourself.
Cons – you will have to empty the tank. Must be careful with abrasive surfaces as it is possible to puncture lining.