- NOT UNDERTAKING INDEPENDENT RESEARCH ON PRODUCT BEFORE USING OR SPECIFYING
There are tons of information online about the different type of waterproofing systems and product. The American Concrete institute (ACI, the largest body of Civil Engineers In the world) which sets standards for all concrete and steel related construction has published a guidelines for choosing the right waterproofing admixtures, coatings and systems. The BBA, British and the WTA European standard setting bodies also have these standards.
For the sake of ease of understanding, clarity and accessibility I will focus on the ACI 212, report on waterproofing admixtures. In these report ACI classified waterproofing admixtures broadly into two categories:
- Permeability reducing admixtures for Hydrostatic Condition (PRAH), admixtures that only fall into this category according to the report are 3rd generation crystalline hydrophilic admixtures that increase the density of calcium silicate hydrate or generate crystalline deposits that block concrete pores to resist water penetration . This admixtures can sufficiently resist water under pressure.
- Permeability reducing admixtures for Non-Hydrostatic Condition (PRAN): Examples of this admixture are pore blocking Cillodial, polymer based and silica fumed based admixtures.
The ACI report states that this admixtures should only be used where resistance to water under pressure is limited or nonexistent. It is not suitable for concrete exposed to water under pressure. In tropical climates with high water table in mostly all regions like Nigeria, Ghana and West Africa generally, this admixture Should not be used for any substructure ( below grade) applications such as foundation, basements, water tanks, sewage treatment plants etc.
Therefore when our Magic Indian and Chinese brothers come to you that their admixture, membranes or product can do anything at least you have a parameter for measuring the efficacy of their claims.
If you like to download the ACI 212 report please visit their site or click the link below
- SEEING WATERPROOFING AS A PRODUCT AND NOT A SYSTEM
Waterproofing manufacturers have spent billions of dollars undertaking continuous research on how best to address and prevent leakages in a structure. We all agree that when there is a failure of waterproofing, which results in leakages and damage to the interior of the it can quite be frustrating.
More often than not, we could avert this, when we understand the industry norm and proven research outcome that waterproofing is a system and not product.
Because you have used an admixture on the foundation, retaining wall etc is not a justification for not using a coating or membrane on the retaining walls and other areas necessary. It is important to know that no matter the amount we spend on quality waterproofing it is never a waste.
- NOT ADHERING TO MANUFACTURERS INSTRUCTION
Sometimes because of omission or commission we fail to adhere to manufacturers direction in using products and we do not get the right result. It is important to always ask manufacturers or their representatives who have been
- RUSHED INSTALLATION AND POOR PROJECT MANAGEMENT
Unlike most other jobs undertaken on site, the waterproofing installation can be a delicate exercise. Typically, in most situation you could have three to four different contractor working on the roof, terrace or other area where the waterproofing is to be installed. The challenge here is that these other group of workmen often times, because they do not fully comprehend the importance of the waterproofing installation may undertake actions such as chiseling, hammering, dragging sharp objects etc that will affect the integrity of the treatment.
The catch here is that, when the waterproofing company are mobilized to site, we must always educate the work men on site to the importance of the exercise and limit their movements from those areas.