Interior water proofing vs external water proofing

Hi, my name is Geoff Woodmansey president of GPW Construction Inc. I have been working in the residential construction industry for over 38 years. My original skill set was carpentry based and I have built hundreds of homes and structures of all sizes and shapes. I have been a general contractor for 30 of my 38 years and have seen some unbelievably poor work to the most mind-blowing spectacular work. I fell in love with construction as I learned and studied everything and anything I could. Which has expanded my skill set 100-fold. From raising homes to replace foundations to installing exotic hard wood floors at $30+ and square foot for materials. At every turn there was something new to be learned.

I recently took on a project that required a renovation of an existing basement in an upper middle-class home. We started demolition in the usual manner and soon discovered that an internal water proofing system was used to manage an existing leaky foundation.

After a little investigation heavy black mould was discovered behind the waterproofing membrane, forcing us to retreat and bring in a mould remediation team at a large expense to the homeowners.

Not only did it cost a ton of extra money, the family had a two-week-old little boy living in a highly toxin home. They had no idea of the risk or the presence of the mould that had been festering and growing behind their walls.

So, why am I taking the time to write about this? Time and time again we run into homes with leaky or damp foundations. Thank goodness most of my client’s choose the best and, in my opinion, the only way to correct the problem is to waterproof the exterior of your home rather than the inside. After removing a half dozen of these interior water proofing systems in the last 10 years and seeing the mess they had caused, I thought it was time to put out the word and share my experiences.

Here’s a little list, it may be short but it’s the simple facts regarding interior waterproofing.

1.      Water will still be coming through your foundation, which will be slowly but surely worsening the condition of an already compromised foundation.

2.      Leaks never get smaller

3.      Mould will eventually start to grow and thrive behind your basement finish’s.

Don’t be fooled by the propaganda and fast talk that several of the company’s that do this work spin. Ask a soils (geotechnical) Engineer or a structural engineer about what’s the best way to waterproof your wet basement. I’m pretty sure what they will say.

All the best

GPW Construction