Wet Basement Page

What can you do about the water in your basement? First we need to look at what exactly is happening in your basement.

1. How do you know if you have a problem with water in your basement?  A few possibilities are:
   1. You see damp or dark spots on a certain area of the floor or walls.
   2. You see paint peeling off walls or floor.
   3. You have wet carpet or if you place something on the floor the bottom gets wet.
   4. You can see your walls bulging inward.
   5. There is dampness where the wall meets the floor.
   6. You have a crack on your wall or floor that has seeping water.
   7. You see stains on your wall from water.
   8. You see moisture coming from a penetration in the wall, i.e. a water or sewer pipe.
   9. You have high humidity if you see mold, mildew or have a pungent odor when you enter the basement.
   10. You see any efflorescence.
2. The next step is to look at what type of concrete you have.
   1. Are your walls concrete block or poured concrete?
   2. Is your floor smooth or rough?  (The test we use for this is: If a child is running across the floor and falls on the concrete, will they burn their knee (like on a basketball court,) or will they skin their knee?  If they would burn their knee your concrete is smooth and if they would skin their knee your concrete is rough.)
   3. Has the wall or floor ever been painted or sealed?

Common waterproofing techniques

These are the techniques that are commonly used to rid basements of water. 

Basement Channeling - This is one of the most common and often recommended ways to remove water from a basement.  It is often used in conjunction with a dehumidifier to remove moisture from the air.  This method assumes all basements will get moisture in them though the walls.  This moisture will run down the walls and into a channel that runs along the wall or in the floor.  This channel then diverts water through the channel to a sump pump or drain to take the water out of the basement.

Pros:  Removes visible water from the walls of a basement.

Cons:  Expensive to have contractors install channels and sump pump, it does not stop moisture from entering your basement, it does not address moisture coming from the floor, the channels become a place for mold and mildew to grow, you must maintain the sump pump and replace it if and when it goes out, electricity is required to run a dehumidifier and sump pump that adds to your energy bills.

Internal French Drains – Many states, counties, and cities have outlawed this method of removing moisture from a basement.  In this method a channel is cut in the basement floor to the soil.  In this channel a French drain is installed going to a sump pump or drain.  Moisture will run down the channel and be caught in the French drain to be taken away by the sump pump or drain.  Be sure and check with your state, county and city building codes to make sure this is an allowed method.

Pros:  Can remove a significant amount of water from a basement.

Cons:  Many states, counties, and cities have outlawed this method of removing moisture from a basement, expensive to have contractors install channels and sump pump, it does not stop moisture from entering your basement, it does not address moisture coming from the floor, the channels become a place for mold and mildew to grow, you must maintain the sump pump and replace it if and when it goes out, electricity is required to run a dehumidifier and sump pump that adds to your energy bills. In most cases a dehumidifier will not remove enough moisture from the basement to avoid mold growth.

Paint-on waterproofing products – This is one the most common and least expensive option.  This involves going to a home improvement store and purchasing a can of waterproofing paint and then painting your walls with it.

Pros:  It is cheap and easy to install.

Cons:  Paint-on waterproofing products cannot stop vapor pressure, it is difficult and expensive to remove when it fails.  Alkali and moisture in the concrete will create saponification and efflorescence causing the paint to “blister” and “bubble” off the concrete over time.

“Tanking” the basement – This is another expensive process of basement waterproofing.  In this method, some type of barrier is placed all around the basement.  Usually this consists of some type of painted or squeegee applied elastameric membrane on the floors and walls.  This membrane is similar to putting swimming pool liner all the way around the inside of your basement.

Pros:  Keeps the livable basement area dry, cracks are covered by membrane but not sealed

Cons:  Between the liner and the wall there is a chance for mold to grow and become a health hazard, if significant moisture gets between the liner and the wall you can see the liner release from the wall and “bubble inward”, this method can be very expensive.

Silicate based sealers such as Endur-O-Seal’s HydraSeal, HydraLoc, and HydraBlok – These sealers are silicate based sealers that are applied with a standard pump up garden sprayer.  They penetrate into the wall and react with the alkali to fill the pores of the concrete becoming a permanent part of the concrete matrix and keeps water from penetrating into your basement.  By filling the pores the concrete is densified and strengthened.

Pros:  Stops water from entering your basement, neutralizes the alkali in the concrete with a chemical reaction thus eliminates efflorescence and saponification, allows the surface on the concrete to be painted, easy to install yourself, less expensive than contractor applied products, permanent, hardens and densifies  the concrete, non-toxic, non hazardous, reduces Radon.

Cons:  Will not seal anything larger that hairline cracks, can not seal painted surfaces.

Solutions to you Wet Basement Problems!

You see damp or dark spots on a certain area of the floor or walls.

This is a very visible sign of a moisture problem.  To fix this issue you would use one of our deep penetrating sealers.  These sealers will penetrate into the wall and stop the moisture.  For extra protection our NCS-2O Negative can be applied.  We recommend the entire wall be sealed to stop damp spots.  Sealing the entire wall keeps the moisture from migrating to another area of the wall.

You see paint peeling off walls or floor.

Paint peeling is a sign of saponification which occurs when activated alkali in the concrete reacts with the petroleum products in the paint.  For best results the paint should be removed.  If the paint is a latex paint and the concrete is poured concrete, the concrete can be prepared with a 50 – 50 solution of Clorox and water and NCS-2O Negative will seal the wall or floor.

You have wet carpet or if you place something on the floor the bottom gets wet.

This happens when a porous material is placed over unsealed concrete.  Water will wick through the concrete into the dry porous materials, making carpet pads, box bottoms or anything else on the floor wet.  If left untreated, this moisture can lead to problems with mold or mildew, which can lead to serious health problems.  An easy test to see the moisture coming from the slab is called the tent test.  Use a 36” X 36” piece of plastic (a large plastic garbage bag works well), a dry, empty cup and duct tape.  Place the cup directly on the concrete.  Drape the plastic over the cup to form a “tent.”  Use the duct tape to tape the edges of the plastic tent so the plastic is pulled tight.  Leave the “tent” setup for 3 to 4 days.  If there is moisture collected under the “tent” when you remove it, the moisture had to come through the slab and the slab needs to be sealed.  This type of moisture transmission is sealed with Endur-O-Seal USA’s Deep Penetrating Sealers.  

You can see your walls bulging inward.

If you can see your walls beginning to bulge inward or you are seeing structural cracks due to water damage, you must excavate outside your basement and perform exterior waterproofing techniques that meet the building code standards in your area.  If water is causing your basement to crack you must fix the source of the water.  No waterproofing technique can stop water that is causing structural damage to the concrete.

There is dampness where the wall meets the floor.

This is called a leaking or seeping cold joint.  This dampness occurs when water seeps in the cold joint and the floor where the wall was poured on top of the footer.  This is a common problem in basements.  Sealing this cold joint is often accomplished by applying a deep penetrating sealer to the wall and floor where the leak is occurring.  If additional sealing is required we can walk you through that easy process on the phone.

You have a crack on your wall or floor that has seeping water.

In order to fix seeping cracks it is necessary to seal the concrete of the floor or wall.  After the concrete has been sealed often the crack will dry.  If you are still noticing some moisture in the crack you can use a hydrophobic epoxy such as EurEpoxy sold by Endur-O-Seal to seal the crack.  We recommend the crack be chased with a right angle disk grinder to approximately 1 inch deep and 3/8 of an inch wide.  The epoxy is then placed in this groove to seal the crack.  Please call before attempting this repair so we may help you with choosing the correct epoxy.

You see stains on your wall from water.

Stains can be caused by a number of factors ranging from efflorescence that has hardened to calcium chloride and rust.  If you are interested in cleaning these stains please see our concrete cleaning page here.  To stop further stains from appearing the concrete must be sealed.

You see moisture coming from a penetration in the wall, i.e. a water or sewer pipe.

You need to seal this water penetration with a silicone caulk.  We recommend the inside and outside of the pipe are sealed with 3M 5500 series silicone caulk.  This caulk is very tenacious in bond and stands up to moisture and weather very well.

You have high humidity if you see mold, mildew or have a pungent odor when you enter the basement.

This is probably the most common complaint we hear about basements.  The mold, mildew and pungent odor are all caused by the high humidity.  Humidity occurs when moisture is entering your basement as a gas or is quickly evaporating after it enters the basement.  Mold can then grow on any surface where it finds food and food for mold is everywhere.  To stop this high humidity and limit mold growth you must stop the water and vapor transmission.  Endur-O-Seal USA sealers will stop this water and vapor transmission.

You see any efflorescence.

Efflorescence is a sure sign of water penetration in your concrete.  As water penetrates into the concrete it activates the alkali that is still in the concrete matrix.  The activated alkali then begins to react with the concrete around it and form efflorescence.  If this situation is not fixed, the alkali will continue to react with the surrounding concrete until the concrete becomes brittle and falls apart.  Endur-O-Seal USA deep penetrating sealers fix efflorescence in two ways.  First, our deep penetrating sealers use the alkali as their catalyst for their reaction.  They use the alkali up so it can not begin the reaction to create efflorescence.  Second, the sealers stop the water that would begin the process of efflorescence.

Do you have other questions about wet basements or a problem that is not mentioned here?  E-Mail us a wetbasement@concretesealers.com.  We look forward to hearing from you and fixing your wet basement problems.

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