All basement leak! Don't they?

Ask the average person why a basement leaks and the first thing they will say is:

"That sorry builder didn't waterproof it correctly and now it leaks."

Years ago I learned a valuable lesson on basement waterproofing that is now reinforced daily as I inspect hundreds of leaking basements both new and old. Since I was a small child I have watched, been responsible for and personally waterproofed many basements. I have always bragged that my basements don't leak. To my knowledge, those basements never leaked.

In later years as an owner of a commercial construction company I was asked by George Wilson (yes the local land/gun guru/Realtor) to build an underground vault in which guns would be stored. Needless to say George didn't need moisture in his vault and I assured him that "my basements never leak." Not one to take undue chances (this vault was to be buried below a parking lot), I hired a reputable professional waterproofing company and installed, what at the time, I understood to be the best waterproofing money could buy. It was a hot moped asphalt three-ply felt system.

You guessed correctly, George's basement vault leaked. Water and guns don't mix. Man was I embarrassed. All of my life I had waterproofed basements using a simple cement parging and cold black foundation coating. Those basements didn't leak. Now I buy and install the best waterproofing system available and the basement leaks. What was the difference? It took me years to clearly understand the simple issue, its called water. Add water and almost all so-called foundation "waterproofing" systems will leak. Take the water away and they don't.

Now are you confused?

It's all in the use of words.

What you have been lead to believe is "waterproofing" is not, it's "dampproofing" and believe me there is a big difference. You don't "waterproof" a basement, you "dampproof" it. The products are designed to keep dampness (moisture) from transferring through the wall system. They are not designed to allow a swimming pool on the outside of the wall and not leak. Therefore comes my conclusion of the secret to basements which don't leak.

WATER FOLLOWS THE PATH OF LEAST RESISTANCE

Keep the water away and they won't leak, add water and they will.

The truth is basements don't leak because of sorry waterproofing, basements leak because of sorry grading and poor drainage. If you have ever read one of my home inspection reports involving a home with a basement, here is what it says:

(I didn't author this, it is part of my reporting software package and other home inspectors who you know use this same system.)

"It should be understood that it is impossible to predict whether moisture penetration will pose a problem in the future. The vast majority of basement leakage problems are the result of insufficient control of storm water at the surface. The ground around the house should be sloped to encourage water to flow away from the foundations. Gutters and downspouts should act to collect roof water and drain the water at least five (5) feet from the foundation, or into a functional storm sewer.
Downspouts that are clogged or broken below grade level, or that discharge too close to the foundation, are the most common source of basement leakage."

"In the event that basement leakage problems are experienced, lot and roof drainage improvements should be undertaken as a first step. Please beware of contractors who recommend expensive solutions. Excavation, dampproofing and/or the installation of drainage tiles should be considered a last resort. In some cases, however, it is necessary. Your plans for using the basement may also influence the approach taken to curing any dampness that is experienced."

Here are the secrets to basements, which don't leak.
Miss one and you may need a mop:

Install a proper foundation drain system (preferable even with the bottom of the footing, with adequate stone and a silt filter mat), which doesn't turn up on the end, but slopes to an open drain or sump pump.

The 4" of stone you put under the floor slab must also have a place to drain. (It must be piped or have an area outside where the grade is below the bottom of the inside stone.)

Use a quality "dampproofing" method up to grade level (don't stop it short!).

Seal and "dampproof" around all wall penetrations for plumbing/electrical, etc.

Slope the entire grade away from the home a minimum of a six-inch drop in ten feet for at least ten to fifteen feet away from the home.

Pipe the gutters a minimum of five foot away.

Don't allow gutters, downspouts and below grade piping to clog or leak.

Keep yard sprinklers, drip systems, condensation drains, sump pump drains and leaky hose bibs away from the foundation wall.

Maintain all of the above in good working order.

Want to spend a little extra to make all of this function better? Add a drainage mat and protection board on top of the foundation wall dampproofing and tru-wall flashing on top of and extending over the dampproofing.

It's not about "waterproofing," it's about keeping the water away and allowing the water some where to go.

Give the water a path of least resistance other than through your wall and your basement walls will not leak!