When it comes to concrete waterproofing, installing waterstops correctly is essential. The horizontal and vertical joints between pours are some of the most vulnerable areas of any structure. If you don’t have a waterstop system installed, or your system is incorrectly installed, you are at risk of leakage and water damage to your property. Because of hydrostatic pressure, water can infiltrate through the joints of concrete structures including:
- Basement walls and slabs
- Subways, pedestrian and vehicle tunnels
- Water treatment facilities
- Canals, dams and locks
There are three general concrete joint types:
Construction Joints – Used between adjacent concrete placements in construction projects.
Expansion Joints – Installed with the aim of separating adjacent concrete pours and protecting them from the stresses caused by compression through seismic events, thermal expansion and live load deflection.
Contraction Joints – Grooves made intentionally to create weaker areas so that the location of cracks due to shrinkage of concrete while curing.
One of the most common methods of concrete waterproofing is applying a PVC barrier into a wall or slab before an adjoining wall is poured. It is strong and flexible, and are installed with the express purpose of obstructing the passage of water through the joint. Although this seems like a reasonably straightforward process, it is highly susceptible to improper installation. Potential installation failures include:
- Waterstop installed too close to steel reinforcement
- Poorly consolidated concrete adjacent to waterstop
- Concrete extending on flange not removed before second concrete pour
- Roll ends overlapping but not welded or spliced together
And these failures are to mention but a few, which is why it is vital that waterstops are installed with great care, and is best left to professionals. Talk to BRA for expert advice.