Throughout my career inspecting buildings, I have never seen a parkade (parking garage) without at least one moisture stain, or active leak. It’s very common for parking garages to leak, and when they do, the stains left behind are often not removed. This may scare off a potential buyer, when in reality the leak may have been solved already.
Here is a list of what to look for when inspecting a parkade:
Efflorescence is a chemical salt that becomes drawn out of the concrete when moisture passes through it. It’s commonly described as a white, chalk- like substance. It stays behind, even after the leakage problem is solved. When inspecting these stains, look at the pattern of the staining. If you see small, perfect circles on a ceiling, you can bet that water has been dripping at some point. A pale, whispy stain with no soft edges is probably left over from construction, and is likely not a concern.
All concrete, during curing, will crack and shift slightly. New, small cracks may form as the live load of the building changes. These most commonly appear as vertical cracks on the exterior foundation walls, and are a common point of water entry. One or two of these can be normal, however, if a wall is cracked in multiple locations and all are leaking heavily, an expert should be called.
Some water ingress at side walls may be caused by improper or defective waterproofing at the exterior wall.
Leakage around drain lines is common, particularly below landscaping and patio decks on ground floor units. Some cast iron drain lines may corrode and leak in the slab, leading to cracks and staining around the connection in the garage. Repairs usually involve removal of the drain base, and part of the cast iron stack, and replacing and waterproofing as necessary.
Widespread leakage, or heavy staining around the parking garage may indicate a waterproofing membrane failure. This is a potentially expensive repair – a building with complete membrane failure may need to remove significant amounts of the landscaping above, and torch on a new membrane. Repairs sometimes involve destruction of landscaping, concrete walkways and patios. The photo above is from a building in Vancouver – they ultimately dug up the entire courtyard and re-waterproofed.
Perimeter Drain Failure
The image above is from a condo with a failed perimeter drain. We can see the rust colored sediment leaching through, as well as a water stain running along the base of the wall. Since the pipe was completely plugged, no water was being carried away from the base of the foundation, into the storm drain, and instead seeped into the basement. The rust color is due to the oxidization (rusting) of the iron in the soil.
Epoxy injections are a popular solution for concrete leaks. They can be identified by small injector plugs that follow a crack line, usually along the ceiling of a parkade. Epoxy repairs will remain forever and cannot be cleaned/removed to hide the repairs. When inspecting these areas, consider that they may have been done recently or long ago – it’s very difficult to determine.
Repairing heavy leaks using epoxy injections is not the best method – the source of the water should be eliminated before any action is taken.
As an alternative to Epoxy Injections, products such as the Kryton Krystol waterproofing compound, can be used with good long-term performance. One advantage to these products is that the finished result looks much more professional – with no visible epoxy residue, oil or injection plugs left over. The installation involves chipping or “routing” out the crack with a chipping gun and packing the product into the trench. The product expands and “follows” the water source, effectively stopping the ingress.
Garage leaks are common, and knowing what to look for can greatly help buyers differentiate between small repair jobs and larger issues. A certified home inspector can help you identify any issues in the building. And, of course, always read any strata documents provided by your seller.
Due to advances in waterproofing technology, we have added information regarding the Kryton waterproofing system (an alternative to epoxy injections), as well as improved the general readability of the article.
Author David Fairbairn is a certified, licensed home inspector serving Vancouver and the Lower Mainland. He has been featured in the media and has contributed to "24" Newspaper, and Global TV. He has spent years working with residential and commercial building projects, and holds a Power Engineering License in BC. Why not give him a call for your next Home Inspection? Call 604 395-2795 or email firstname.lastname@example.org today!