Exterior Drainage Systems

A typical memrane installation requires several steps.

1) Site Preparation.  811 must be called to mark any underground utility lines.  Any private lines that have been buried must be made known to us (sprinkler systems, electric for street lamps, electronic dog fences, etc), and clearly marked.  Any obstacles must be moved out of the way.  Bushes, flower beds, A/C compressors, decks, etc.

2) Excavation.  The majority of the time, excavation for a membrane will require the use of a machine.

Exterior Membranes

Exterior Membranes are one of the best steps you can take to protect your foundation against water and moisture damage.   20 or 30 years ago, most foundations were given a quick tar coating during construction.  This dissolves fairly quickly from constant contact with moist acidic soil.  10, 20 or 30 years later, there is usually nothing left.   Today, we have much stronger materials that can withstand the test of time, even in the harsh below grade environment.

We use sheet membranes that are a 2 layer combination of HDPE (High Density Poly Ethylene) and Bentonite Clay granules.   Bentonite clay is a natural occurring substance that swells significantly when in contact with water.  Once swelled, it seals any nearby voids, and prevents the transmission of any water or moisture.   We use TegraSeal and CETCO brand membranes, depending on the specific application requirements.

Exterior Footer Drains

Whenever possible, installing an Exterior Footer Drain is a great protection for your foundation.  Unfortunately, not all houses are good candidates for Exterior Footer Drains.  For an EFD to work effectively, the property requires a significant amount of slope so that gravity can carry water away from the base of the footer*.  Most properties do not have enough slope to accommodate this.  EFD’s on crawlspace foundations are more common, since they require significantly less slope.  But if your property allows for it, you should strongly consider an EFD to catch water BEFORE it can get to your foundation.

(* using an exterior sump pump with an EFD is a possibility, but we usually recommend doing that only in severe situations, as an exterior pump tends to be less reliable due to it’s exposure to the elements.)

Foundation Crack Repairs

Poured concrete foundations develop cracks. That is just the nature of the beast. When these cracks go all the way through the wall and allow water to penetrate, then you need to act. There are 2 ways to seal foundation cracks.

1) Exterior Multi-Layer Crack Repairs

Whenever possible, it is always best to seal a foundation crack from the OUTSIDE.
By doing this, you are:
a) working with physics by allowing the water pressure to push sealant INTO the crack.
b) providing a multi material covering that has increased tolerance to the acid inherent in soil.
c) building in fault-tolerance by sealing a much larger area than just the crack location, so when the wall shifts and the crack widens, you are still protected.

2) Interior Epoxy/Urethane Injection
Sometimes, you cannot access the foundation crack from the outside. When this is the case, Interior Epoxy or Urethane injection is an option. This allows us to fill the crack using a low pressure injection system that fills the cracks from the inside out. Epoxy injection does not expand after it has cured. Urethane injection can expand, but only up to 20% after curing. That means if the wall moves and the crack widens significantly, the injection repair will have to be done again. This is why we always recommend performing EXTERIOR crack repairs whenever possible.