Obtain required bond strength
A waterproofing system is only going to provide protection when it remains bonded to the surface on which it is installed. A system that does not stick will fail to adequately protect the structure below. Therefore, a waterproofing assembly must be selected based on achievable substrate preparation requirements because site constraints can inhibit the preparation work needed for a specific system. Such constraints can include restrictions on large construction equipment, noise/dust generating restrictions due to occupancy, or schedule constraints that may fast track repairs.

Consider snowplow resistance
A waterproofing system must be specially designed to resist damage and perform adequately on open parking and podium decks as well as roof parking levels where snow removal is undertaken. It is equally important to have a proper maintenance plan to ensure snow removal is undertaken with minimal impacts to the waterproofing. A hard wearing surface and high bond strength will often correlate with damage resistance. Ideally, the waterproofing layer will be physically separated from the driving surface by a topping or asphalt wearcourse to provide greater protection against snowplows.

Provide ultraviolet stability
A waterproofing system exposed to sunlight must withstand the damaging effects of ultraviolet (UV) radiation because sunlight can physically break down some waterproofing systems and reduce their effectiveness. Additionally, UV radiation can cause discolouration and other surface distress.

Ensure ease of maintenance and repair
Most waterproofing systems require localized repair and maintenance at some time during their anticipated lifespan to address localized deterioration and achieve the overall service life. A key consideration is how easy and cost-effective it will be to address potential deterioration. Each waterproofing system requires a specific repair approach that will impact the structure’s operation in different ways and costs.

Code compliance
New parking structures must have waterproofing systems designed to be in conformance with CSA S413. This standard includes minimum design requirements to increase performance levels and durability. Attention to these code requirements is required to ensure proper implementation.

Cost
A waterproofing system should be economically feasible or it is of no use. The type of property and its expected service life may dictate the suitability of a high- or low-cost option (i.e. a class “A” commercial property compared to a mid-rise condominium building). However, high cost does not solely correlate to effectiveness for a particular situation.