Exterior waterproofing is the best way for basement waterproofing. If you can keep the foundation from ever getting wet in the first place, that is great. But the truth is, you can’t keep it that way forever. The reasons are many, but it basically comes down to outside conditions. Anything you do out there is subject to changing extremes in weather, temperatures, soil conditions, pests, landscaping errors, and even your neighbor’s poor choices. Because it is constantly under assault by these factors, it is hard to warranty the home for any significant length of time. But in the short term, of course, a bone-dry foundation is best.
The other time exterior waterproofing is best, is during the construction of the home. This is because you have one shot to really do it right, and maximize the openness of the foundation. We always advocate going the extra mile in waterproofing during construction, but only in conjunction with interior methods as well. Why? Because, again, exterior waterproofing is short-term.
At Superior Waterproofing, we would be remiss to tell you pros with no cons, so consider the following. With exterior waterproofing, you require the very same system you would do inside the home, a wall liner (or sealant) and drain tile. We cover everything up with stone and soil. The natural order of things is that the soil will settle, and ultimately the drain tile will clog, even in the best of circumstances. If you want a long-term solution, it can be accomplished by doing both, exterior and interior together, or even by interior methods alone. So in the long haul, exterior methods often equal a waste of money.
Consider too, when the drain tile clogs. Now the foundation is pressurized. So the water will sit around the outside of the home looking for a weak spot. Most often, when retro-fitting existing homes with exterior waterproofing, obstacles prevent 100% of the foundation from being waterproofed (think of driveways, garages, additions, etc.) That means that the water is simply going to find the areas it wasn’t leaking before, and start leaking! You have basically paid a lot of money to change the leak from point A to point B.
From a purely cost standpoint, consider that not only does waterproofing cost more in terms of material quality in exterior products, but you have excavation costs, landscaping costs, and much more. Oftentimes, exterior work can be 3 or 4 times more expensive than interior work.
From a structural standpoint, homes that have cracks in the walls may not be good candidates for excavation and exterior repair. The reason is that the wall (while still structurally stable) is not new. When you subject an old wall to brand new soil pressure (that it clearly struggled to sustain, hence the cracks), it can become further compromised. Those cracks can widen, the walls can bow inwards, and in some cases, severe damage can result. This can take as little as a few weeks, or as much as a few years. But the risk is real, and can potentially cost thousands. Interior waterproofing can often mitigate this concern.