SUPPLY & APPLICATION OF APP WATERPROOFING MEMBRANES

  Any building or structure without a suitable waterproofing membrane system is highly likely to be infiltrated by water, possibly causing structural damage. It has been reported that 83% of all building defects are water-related & failed membranes represent a large percentage of this figure. The cost of rectification can be substantial, so to avoid failure, the correct waterproofing membrane selection & application is essential. 

Follow the Dolphin Enterprise Checklist before finalising the most suitable one for your requirement.

• UV Stability - If the  waterproofing membrane is to be exposed to the sun, than it must be UV stable or UV resistant, else it will degrade over time. 
• Elongation - This is the ability of the membrane to stretch & it is measured in percentages. An elongation of 150% means that the membrane can stretch to 1.5 times its length when pulled. Elongation is a must in buildings that will move, such as high-rise buildings, or buildings made with steel, which is flexible. This property will allow the membrane to stretch over cracks that may develop in the future. Membranes with elongation properties of over 200% are also available.
• Breathability - One disadvantage of good waterproofing is that if water does happen to enter into the structure from a point and spread across a surface, that water is trapped inside the structure, and cannot get out. Breathable membranes help to release that water to the air in the form of water vapor. So some membranes are designed to prevent water from passing through them, while at the same time allowing water vapor to pass through. So over time, breathable membranes allow trapped water to evaporate into the atomosphere.
• Tear Resistance - this is an important property, as many membranes that have good elongation also can tear easily. Take a small sample of the material in your hand, and try and tear it into two pieces. This gives a fair idea of its tear resistance. You are looking for a membrane that will not tear even if a reasonable force is exerted on it.
• Abrasion Resistance - this is the ability of a membrane to withstand wear and tear. As most membranes are covered concrete screeds and tiling, the abrasion resistance comes into play during the construction period, when workers are walking on the surface, dropping nails and screws, and scraping hard objects like rebar against the membrane, which can damage it. A very soft membrane with low abrasion resistance may get damaged in such a situation, which can cause it to leak.
• Chemical stability - check that the membrane is chemically inert with respect to its environment in the building. Some membranes, especially outside basement walls, are exposed to the soil and rainwater outside.
• Food Safety - membranes can be applied to the inside of concrete water tanks to make them waterproof. In this case, the membrane must be food safe, as the water is in contact with the membrane.
• Geometry - if a membrane has to be installed over a complicated shape, such as the junction of a column and beam, then a liquid applied membrane is preferable, as it can be applied to any type of underlying shape or structure. A sheet membrane would form folds and creases and leave gaps between the underlay and membrane.
• Case Studies - ask the manufacturer or contractor to give you case studies where the membrane has been used. Ideally, it should have been in place for over eight years. Check with the building owners to see if any leakage or problems have occurred.