Garden Beds

Our garden beds have shown evidence of water seal degradation for years. In the past leaks from the garden beds into the garage have not been repaired, but drip pans were installed to divert dripping water to the drainage system. Unfortunately, this masked the symptoms, but allowed the problem to get worse. The following diagram shows our 8 garden beds that are built into the structure of our building. 

Garden Bed 1 (GB-1) is located above the garage entrance and in front of unit 4. The following photos show the garden bed from above, and a very large paint blister that is above the pedestrian door to the garage. When first observed, the paint blister was filled with water and then ruptured to release the water. It is most likely coming from water leaching through the garden bed base.

Garden Bed 2 (GB-2) is is the first garden bed on the raised entry walkway on the right along the Unit 4 terrace. A penetration through the garage ceiling (above guest parking) carries an irrigation pipe into this garden bed, and has been leaking for a number of years. A drip pan had been installed to divert the leaking fluid to the drainage system. The photos below show the garden bed from above, and the drip pan installed on the garage ceiling. Note the effect on the surrounding concrete.

Garden Bed 3 (GB-3) is the second garden bed on the raised entry walkway on the right along the Unit 4 terrace. The photos show the garden bed from above, and a nearby drain pipe from underneath. Note the drip tray beneath the drain pipe. The water leaching through the concrete may be from the garden bed and/or the walkway near the tile drain. The stalactites growing on the concrete is a result of calcium hydroxide being leached from concrete which indicates that the concrete is degrading.

Garden Bed 4 (GB-4) is the garden bed at the end of the raised entry walkway on the left. The photos below show the garden bed from above, and from the side along the boundary area with 46VP. Note the water leaching from the garden bed at the slab level. A tap test of walkway tiles near the garden bed and the timber balustrade indicated that the tiles are debonding.

Garden Bed Water Seals: A preliminary investigation indicates that our garden beds had been water sealed with bitumen which would be consistent with the method used in the original bathroom water seals in our building. It is not unusual for garden bed water seals especially with irrigation systems to degrade with time. It is clear that the time has already come for our garden beds to be resealed.
Water Sealing Garden Beds:  Re-sealing the garden beds will be difficult, messy and expensive. Removing, preserving, and reinstating plants and soil in complicated. Also, repairing any degraded concrete would also be messy and expensive.
Climbable Elements: A number of our garden beds do not meet current building code requirements as they are climbable elements near barriers meant to protect people in trafficable areas elevated >1m above a lower surface. Repairing the garden bed water seals may trigger a requirement for our garden beds to meet current building code requirements.  The strata committee will discuss this issue with a BCS consultant. The relevant garden beds include: GB-1, GB-4, GB-6, GB-7 & GB-8. The most troublesome one is GB-1 as it is at a very high elevation above the garage entrance and may require a one metre high barrier above the current garden bed level.
Degraded Concrete: It is difficult to accurately assess and quantify the degree of degradation in concrete from the surface. Intrusive inspections are necessary to reveal the extent of degradation. This type of work is priced on rates and can result in unexpected high costs. Delaying repairs on degrading concrete is very unwise as degradation and repair costs can exponentially rise with time. It is imperative to eliminate the source of the problem quickly and to repair the damage. Discussions with a reputable remedial builder suggest that current damage appears to be limited to the localised areas shown in the photos.
Where do we start?
The strata committee is currently working on an integrated strategy to address these issues concurrent with external entry way improvements. The strata committee is looking forward to the relaxation of social restrictions to allow the opportunity to discuss these considerations with all OC members.