Case study: Moisture in concrete garage floor, Alexandra Hills

Alexandra Hills
Moisture problem – 58sqm garage Alexandra Hills, Qld

The owner of this property called advising he’s having problems with moisture coming through his concrete floor and brick walls.

He has a 50,000 litre water tank directly on the outside of one of the brick walls and his solution to fix the moisture problem and get a coating on his floor was one of significant expense and labour.

The garage was cut into a hill. The outside retaining walls were virtually butted up to the back walls and backfilled so when it rained, the moisture would build and penetrate the walls and sit on the floor.

We were tasked to find a solution without demolishing the outside walls, removing the water tank and dealing with the moisture problem before putting an epoxy flake floor in place.

The moisture issue is known as hydrostatic pressure and poses significant risks to an epoxy floor. The natural direction for moisture within a floor is up and when pressure builds, and particularly over a sealed floor, eventually, the epoxy blows off.

As we were also dealing with a vertical moisture problem, we had to determine how far up the wall the water was travelling.

What we had in terms of case history was a suppliers dilemma some years before where one of their customers had to deal with moisture proofing against the effects of rising tides.

What they found was that even at the ‘high tide’ mark, moisture continued to rise above the level. Knowing this, we found the height of the moisture at the peak and used an epoxy product, applied two feet above this mark to seal the wall and the floor, before coating over it using our flake system.

This solution represented a big financial saving for the client who had further plans for installing pipes, dredging and a reasonable amount of earthworks.