CRACKING

Cracking and movement has been, and I think will always be, a serious problem unless we pay more care and attention to detail. There are many reasons why this problem occurs and fixing the damage is usually very costly indeed.

Here is one story that had us a little perplexed when we tried to find the cause of this problem. This was a house built approximately 20 years ago using Widebay clay block, which at the time was used in thousands of houses all over the country.

Sever cracking on the corner.

 

The original owner who still lives in the house engaged the services of a structural engineer.
The report stated that the steel reinforcement bars were corroding. This lead to them swelling up and literally blowing the brick work apart. We removed a small section of the brick to reveal that the 16mm deformed reo bar had indeed corroded and swelled.

At first glance, the rod looked as though it had completely rusted through, so I used a hammer and cold chisel and began chipping away fully expecting the rod to just snap in half.
To my surprise, the corrosion was only a millimetre or so thick and the rod looked like brand new underneath. It doesn't need to swell much at all to do this kind of damage.

Our only solution was to cut out the brick work where ever there was cracking up the full height of the wall, remove the rust and treat the steel with the best products available.
It was only a short time into the rectification that we finally discovered why this had happened.

Over the last 20 years, the owner was watering his gardens that were on the three walls of the house that were cracking. He was also washing down the walls using salty brackish water. This explained why the other walls were not affected. The walls were only ever treated with a water repelling silicon compound when the house was first built. This type of construction using the clay bricks required a maintenance program that required further applications of the silicon spray to be applied at least every 12 months to 2 years.

After the rectifications were complete, the owner had all of the walls cement rendered and finally stopped washing down the walls with salty water.

I must admit that he  was a little embarrassed but was really happy with the end result. The work was completed some time ago and there are no signs of any cracking anywhere, at least for now!

If you have any problems like this, I highly recommend contacting the engineer that I use.
You can contact Matthew Cornell via this link. He has an excellent article on this very thing.
Click on this link.   https://www.cornellengineers.com.au/cracks-and-gaps/

Tip!  Do not plant gardens up against the walls of your house and certainly do not wash any thing in salty water.

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Cheers for now.