My Take on Construction Mistakes

My Take on Construction Mistakes

Over the past 20 years as a builder and inspector, I have gained plenty of knowledge as to why building defects happen. Here’s my top 5;

1.       No Man’s Land:

I often link building construction to human anatomy. Many parts rely on each other or cross paths. Defects are especially common in junctions where different trades have performed their work.

A good example is the junction of a balcony and door sill. This area relies on the concrete formwork to achieve the minimum vertical upward termination, the water-proofer to membrane the sill substrate before the door is installed, the window installer to install the sill flashing, and the floor contractor to install the internal water stop before installing the floor covering.

If just one of these 4 trades deviates from their role in the process, it can lead to building failure from rain-water.

2.       Trades Push On:

Most trades sub-contract to builders or are paid subject to the completion of a task. They are often not employed on wages.

Therefore, if they turn up to a building site and things are not quite right or ready, they will often ‘push-on’ with their work. Contractors cannot afford to leave a job, with no work to go to that day, especially if working in groups. They can have a narrow focus of getting their job done and ultimately getting paid.

A good example is the construction of a box gutter. The roofing plumber relies on the carpenter to achieve the correct frame to accommodate drainage fall. If the frame is not quite right, it’s often all too hard to get it fixed so the attitude is to push-on and get paid.

A phrase I often use with contractors is, ‘if you touch it, you own it”.

3.       Poor Supervision:

In my opinion the best building practice to achieve quality construction outcomes is to have a good foreman, 2ic, supervisor, or construction co-ordinator.

Clear and detailed instructions to contractors are also important in order to manage the expectations of the job.

If areas of no-man’s land are identified, then it’s often a good idea to get one contractor to take ownership of that area. A good example might be to get a contractor that is responsible for painting and plastering. A good painting job relies heavily on a good plastering job. By combining the two, there is no finger-pointing between the two trades.

4.       Faith in the Contractor:

Since moving into the consultancy space, I have learnt more about building from a regulations and technical perspective in the past few years than I did in the 15 years I spent as the Head Builder of my construction company.

There are many trades that simply require no formal qualifications to work in construction, let alone understand or have a copy of the Australian Standards or the Guide to Standards to Tolerances that their workmanship is bound by.

Installation manuals from product manufacturers also contain extensive and valuable information and diagrams but are often ignored. A good example is the James Hardie Scyon Secura External Flooring Installation Guide. This guide clearly explains how to perform the job to achieve compliance. However, there are too many occasions to count that I have seen this product installed on site with the workmanship not even close to the requirements set out in the guide.

I recommend that builders start to take a bit more ownership of how they instruct contractors to perform works. After all, it’s the builder that wears the majority of risk in the building process.

5.       Prevailing Weather:

Melbourne’s prevailing inclement weather sweeps in from the North-West. However, building design does not often take this into account, leaving the building feeling naked and exposed to the elements.

Cascading rain-water on cladding or glazing can have a heavy impact on window and door openings where attention to detail in flashings, door tracks and weep-holes are critical.  

Many buildings have no roof cover and you simply go from inside to outside with no protection from the weather. Water can ingress the building far more easily.

In multi-unit low rise developments, I often encounter extensive water damage to the north-west elevation from a building defect compared to other elevations with the same defect, simply due to the direction of the prevailing weather.