FAQs Basement And Foundation Waterproofing

There are several ways to keep your basement floor dry, not all are "waterproofing," Real Waterproofing starts on the outside of the foundation stopping water before it moves through the wall.

Interior methods of dealing with water include an underfloor drain system (Drain Tile) which usually discharges the water back outside or a cove channel system that sits on the basement floor and also pumps the water back outside.  We call these water management since the water is never stopped, just redirected.

 There are several wall coating products that are sold as waterproofing but we find the product life to be extremely short under minimal water conditions.  They tend to flake off the walls with continous water pressure.

While Drain Tile tends to outsell the other methods, it's uses should be limited to "hydrostatic" conditions where water is moving up through the basment floor (which is fairly rare).  Because you're not stopping water flow, concrete damage, mold and mildew will all continue.  If the pump stops from a power outage or old age, your basement could easily flood.

Most types of foundation waterproofing require a lot of manpower and equipment to rip out and put in a water-management system in a timely manner.

The good news is that targeting basement water on the exterior using bentonite can be a fraction of a home drain-tile system and it stops the water!

Drain tile is best used for water moving up through the floor (hydrostatic), a fairly rare condition.  Since the collection pipe system is under the floor, water flowing through the solid concrete or stone walls will bypass the system if the hole is above the basement floor.

If you browse this website, you'll see many photos of basements with drain-tile and the water is flowing through those above-floor cracks.

Most home are built above the "water table" otherwise there would be continuous water pressure on the exterior and you would see water all year long.  Concrete foundations tend to be porous, either at the joints  or through the walls themselves, we've seen cinder blocks "bleeding" water through the block faces.

When homes are built, the dirt excavated and backfilled creates a porous bowl.  Rain water will collect in this dirt bowl and if any cracks or holes develop in the foundation, you will have a wet basement.

There's several different versions of bentonite waterproofing powder with different additives for specific applications.  Just like there's many different concrete mixes, bentonite can be blended for maximum water-stoppage  in different  ground conditions.

If applied correctly with a nice chunky, thick mixture, the bentonite waterproofing should last for the life of the structure.  We've done remoldeling work on buildings built during the late 70's that used bentonite membrane waterproofing.  We've had to excavate portions of those buildings exposing the membranes fully intact and working.  

Unless there's extensive remodeling done or major structural damage to the foundation, the bentonite should look the same for the life of the foundation.

In the Midwest we tend to see homes with cracks all of the time.  While we aren't structural engineers, we find that most homes will not collapse with minor cracking but those cracks you see on the inside of the basement will go all the way through to the outside.

Sealing the basement wall cracks on outside is the best way to stop water and help the walls dry up.  The easiest method is to use the bentonite injection system where no digging is required, the dirt next to the wall is injected with waterproofing bentonite which seals the cracks, stopping the water.

Some contractors want to dig up your foundation, usually 36" down and apply a rubber membrane to the foundation and turn it out into the yard.

They excavate this area, the landscaping  is destroyed during the process.  The membrane is attached to the wall and then they backfill the area with porous dirt, nothing is compacted.

If you see a vertical crack on your foundation, it goes from the grass all the way down to the basement floor, it is very rare for a crack to stop in the middle of the wall.

While this method seems to stop water for a short time, our experience is that the water eventually works it's way around the porous backfill, moving around the membrane back to the cracks on the lower portion of the wall.

Great Lakes Waterproofing uses, or has installed most modern waterproofing methods except for this style of exterior rubber membrane.  We find the failure rate after a few short years to be extremely high and the amount of landscaping destroyed to be unexceptable.

Drain-tile combined with a sump pump is a great solution for pumping water outside, if the water is hydrostatic, or "high water table" it's one of the only solutions.

Unfortunately, a drain-tile system is not waterproofing it's water management, it does not stop the flow of water through the foundation, it captures it inside and pumps it back outside.  If the pump stops working (power outage) or the pipes get full of sand and dirt, or worse, iron ochre or calcium, the system may not work permanently.  About 60% of the homes we work on have a drain tile system, it's either blocked or the water is moving through the walls higher on the basement wall.

This is one of the most popular responses we hear and we like it but it's just part of a larger solution.  

If you have low spots next to your foundation, they need to be built up so water doesn't form puddles next to the foundation.  Most codes require 6" of spacing from the top of the concrete foundation to the dirt and then slope down away from the foundation.

With older foundations, the damage is already done and it's usually  inches or feet below the surface where the water is coming in, building up dirt does nothing.  A plastic sheet will rot away and may make matters worse with a funnel effect.  The porous sinking soil will collapse the plastic, it will rip at the low spot, and now all of the landscaping is draining in your problem area.

Unfortunately we don't really have innovative waterproofing, we use methods that go back decades and are still working today flawlessly.

Great Lakes Waterproofing doesn't stick to one brand or method, we use most of them and apply the best solution.  Our manufacturers are always innovating waterproofing but it's typically on a smaller scale, changing the waterproofing properties of our membranes and  bentonite blends.

With more advanced research and development they're able to create better versions of the basic formula for a wider range of ground and soil conditions.

Great Lakes Waterproofing does not believe in the hard sell, some of local waterproofers will spend 2-3 hours flipping through pages of information and will not take no for an answer.

We like to take a good look at the property using advanced water detection equipment like infered thermography and contact water detection meters.  We look outside to see why your getting water in and what's the best way to stop it (outside).

If our estimates go long, it's because the customer asks a lot of questions, our sales team has years of experince with foundations, water and ways to have a dry basement.  We love helping the customer become more informed about basement water issues.

We don't push you to make a decision right away, we want you to make an informed decision on your own time, that's why most home-owners call us back when the time is right.

Most professionals don't consider letting water inside your basement and pumping it out with a sump pump to be real waterproofing, we call it water management.  Real wateproofing is stopping the water completely on the outside of the foundation.

While rare, there are some situations where a drain tile and sump pump are the best method to collect basement water but it should only be used when none of the other options are available.

Around 60% of our homeowner waterproofing projects are homes that have a drain tile system with a sump pump (building code since the early 8o's).  We even see a lot of homes that don't have a sump pump in the sump basket, why is that?

When the contractor built the home, he wasn't running into water with the excavation, since the ground was dry, the chance of having water moving up through the foundation (hydrostatic) is really rare.  The contractor saved a few hundred dollars by not installing a pump.

Years later, when the foundation walls develop cracks and holes, a pump may be needed but usually the water gets to the floor first before it even makes it to the sump basket.  We see a lot of wet basements with a dry sump.