Concrete has been around for a long time now, and as it is a porous material, so have ways to waterproof it. The past 40 years or so, we have seen very progressive change regarding HOW we can waterproof structure. The new solutions are installed faster, work better, and last long than the older methods. Unfortunately, building codes often take a lot longer to align with the pace of technology. This is why it is so exciting to see the New York City (NYC) Building Code confirming new revisions to restrictive waterproofing clauses (released in 2014) that previously required the use of an external waterproofing membrane for concrete structures.
The key changes in the clauses allow designers to make more appropriate waterproofing decisions for the unique characteristics of their building designs, opening the door to innovation and progressive change:
1807.3.1 – Floors required to be waterproofed shall be designed and constructed to withstand the hydrostatic pressures to which the floors will be subjected. Waterproofing shall be accomplished by creating a continuous water seal below the floor using appropriate waterproofing materials. Joints, penetrations and other interruptions shall be sealed in accordance with manufacturer’s recommendations. Floor waterproofing must be transitioned to accomplish a complete tie-in with the foundation wall waterproofing.
1807.3.2 – Walls required to be waterproofed shall be designed and constructed to withstand the hydrostatic pressures and other lateral loads to which the walls will be subjected. Waterproofing shall be applied from the bottom of the wall to not less than 12 inches (305 mm) above the maximum elevation of the groundwater table or as directed by the registered design professional. The remainder of the wall shall be damproofed in accordance with Section 1807.2.2. Joints, penetrations and other interruptions shall be sealed in accordance with manufacturer’s recommendations.
The new building code change allows project designers to choose the best waterproofing product for their project, rather than being hand-tied by the former restrictive clause into using only an external membrane. The updated building code supports the evolution and demand for better and more reliable waterproofing methods; moving forward with new innovations in durable and sustainable building design.
One of these reliable waterproofing methods is crystalline technology’s category leader, Kryton’s Krystol Internal Membrane (KIM). When combined with water, KIM’s proprietary chemicals react to form millions of needle-like crystals. These crystals grow and fill the capillary pores and micro-cracks in the concrete, blocking the flow of water. As time passes and stresses form new cracks, any incoming moisture causes the crystals to reactivate – ensuring continuous waterproofing over the years.
KIM is also the only PRAH (Permeability Reducing Admixture for Hydrostatic Conditions) on the market, and is an attractive concrete waterproofing solution for Architects who employ the look of exposed concrete within their design, yet need the concrete to be very effective against hydrostatic pressure. As the benchmark concrete waterproofing admixture, KIM reduces project costs, saves time, and mitigates the overall risk of damage to the concrete structure.