How to Do Exterior Waterproofing


There are many ways to do exterior waterproofing. Many depend on your budget, how extreme the problem is and what is causing the leak.

It’s best to install an exterior waterproofing system when the house is still under construction, as installing it on an existing house poses many challenges and could create problems. Basements in many older homes are often damp and leaky, making them unsuitable choices for new bedrooms or a great family area.

  • You first need to inspect the perimeter of your home to make sure the ground bordering your foundation slopes away from it and not towards it. Ensure the ground has at least a 2” per foot slope
  • Ensure the drop spouts are discharging water at least 5ft away from the foundation. Take note of shrubs or plants near your foundation. Ensure they are at least 12” away and on a slight slope away from the foundation, as rooted roots may create a pathway for water to flow down your foundation.
  • Repair any defects like cracks or where concrete tie rods and pipes go through the concrete.
  • For serious water problems, consider trying a French drain, which is a continuous system of pipes running beneath the basement floor and along the whole perimeter of your basement.
  • One type of waterproofing, known as “positive-side proofing”, is a technique that uses a waterproof coating or waterproof membrane to bar water from getting into the basement. In the membrane treatment, a thin layer of “Bentonite” clay or plastic sheet material is used to create the water barrier. The thick, tar-like consistency in most exterior treatments can be applied by spray or brush. To do this you will need to dig down to be able to apply the coating down to the foundation.

If all you efforts to waterproof fail you may want to consider installing a sump pump– a hole with a pump in the basement floor – to help discharge water out of your house when water level rises too high. This will not keep the water out but will pump the water out as soon as it enters.

You best decision will be to hire a professional plumber to help you with your home improvement project. A professional plumber will be able to figure out where the problem is instigated at and then will have the skill, experience, and tools to do the job professionally so you can begin to use that extra space.