Having blogged about basement waterproofing for well over 2 years now, I’ve come across plenty of misunderstandings about sump pumps and their place in the waterproofing “solution bag.”
Many customers call, thinking that all they need is a sump pump, when the majority of the cases, it couldn’t be further from the actual solution.
The sump pump is a mechanical device that sits on the front lines of any moisture issue in the basement. It is designed to be the easiest, quickest, and most volume displacing method of getting water out from underneath your basement floor. Sump pumps are a great answer if all you have is ground water coming in contact with your basement floor. However, it’s very rare that this would be the ONLY way that water was trying to get into your basement.
There are two other ways that water typically comes into the basement (and I’ve talked at length about these): inward migration of moisture through the foundation walls and water coming in through the gap between the footing and foundation wall.
Unless the moisture and liquid water somehow only get diverted to underneath the basement floor, and you experience absolutely not seepage around the floor/wall joint, then it’s possible that the sump pump might be the only solution you need. But 99% of the time, the sump pump is only part of the solution.
Other solutions to consider:
A subfloor drainage system can help to capture most of the water coming through the footing / wall joint that a sump pump alone would miss. Interior drainage is connected to the sump location and can in fact help the sump pump to deal with more volume then just the sump alone. Drainage at the other end of the basement can help to ferry water through it’s channels to the pump, where as in the pump would have to work twice as hard to reach the same water.
Water, a natural level, will always seek its own level. As a sump pump works it lowers the level of water near it, however, the water further away is still at a slightly higher level. This creates a shift and the water will rock to level itself out naturally. If drainage was present, the water could uniformly be removed faster and with less resistance.
Foundation Wall Vapor Barrier
Vapor Barriers have had people confused for years now. Correctly attaching a vapor barrier directly to the foundation wall will drastically limit humidity and the level of moisture that can break into the basement via the foundation walls. Vapor barrier can be directly connected to interior drainage and any moisture or liquid water that is trapped by it, will find its way to the drain and be directed to the sump pump basin.
One of the most common questions that I’ve received about Vapor Barrier is “Do I need it?”
The answer as I’ve stated before, is a strongly suggestive YES. It will help to completely address all the possible entry points of moisture into the basement, provide long term protection against wall leaks and wicking.
If you don’t use a vapor barrier, I wouldn’t suggest finishing off the basement until you did.