Barrier Waterproofing Systems

What went wrong?

We at Barrier Waterproofing Systems receive dozens of calls every week to examine and evaluate residential
foundation water problems. Over 80% of the homes we inspect are in the 12-year or younger age bracket. We're
constantly asked:

"What went wrong?"
"How could a house so new already have drainage problems?"
"How did this pass inspection?"

"Did the builder meet code specs?"

"Why wasn't this discovered during our inspection?"

... and so on. The answers to all of these very logical questions become obvious if we have an understanding of
how foundation drainage is usually installed during construction, if installed at all. We hope you'll find the
following informative.
Dealing with a wet basement can be extremely frustrating. Seepage can deteriorate foundations, damage walls
and flooring and destroy personal property items such as irreplaceable photo albums and family heirlooms.
Insurance coverage for wet basements varies from state to state and company to company. But typically, the
damage from water seeping in from the outside or backing up from the sewer is not covered by standard
homeowner policies. In some cases, special coverage can be purchased to cover these risks, but it is usually
limited in the types of personal property it covers and amounts of coverage that may be purchased.
It is the responsibility of each homeowner to prevent water damage before it starts. This can be done through
proper home maintenance and installation of systems engineered to prevent, intercept and remove water before
it gets into the basement.

In order to prevent wet basements, it is important to understand where the water is coming from. Below are
some of the common sources that cause seepage into basements:

1. Groundwater in water-saturated soils being forced into the basement by hydrostatic pressure, either through
wall cracks or porous concrete walls, the cove area (where wall meets floor) or through cracks in the floor.

2. Storm sewer water from the municipal storm sewer system backing up into the home’s existing perimeter
foundation drain and leaking into the basement (this can only occur if perimeter foundation drain system is
connected to the municipal sewer system)

3. Sanitary sewer water from a combined municipal storm/sanitary sewer system backing up into the home’s
drainage system causing sewer water to come up through sink drains and floor drains on lower levels.

Basement water problems are often unpredictable. A home may have had a dry basement for years, but start to
have water seepage problems during a wet spring, even though the wet weather is not the worst that the house
has seen in the past. Area development may cause groundwater levels to rise, may increase storm water runoff
and overload storm sewer systems, or affect underground springs. The waterproofing on the exterior side of the
basement walls may have developed cracks due to house settlement or various soil conditions. Tree roots may
have damaged and blocked the underground drain tile.
When homeowners experience wet basements for the first time, it is imperative to determine if the water
problem is going to cause further damage. Essential to solving this question is determining where the water is
coming from.
Groundwater Under Hydrostatic Pressure

Symptoms that point to subsurface groundwater under hydrostatic pressure are water coming up through cracks
in the basement concrete floor or water coming in at multiple locations (cove joint, wall cracks, etc.)

If you have an older house within a town and the house has a basement with no sump pump, it is likely the
perimeter foundation drain system, if any, connects directly into the city storm sewer system. If the level of the
basement is below the street level, there is the potential of storm water backing up in the city storm sewer
system and being pushed into the perimeter foundation drain system. This can saturate the soils around the
house at the basement level with storm water under hydrostatic pressure, causing water to leak into the
basement.

Another source of subsurface groundwater is an underground spring.

No matter where the water is coming from, there are two primary methods of preventing subsurface groundwater
from entering the basement.

1. Apply advanced waterproofing on the exterior face of foundation walls.

2. Install an interior perimeter drainage system to relieve the hydrostatic pressure and discharge the
groundwater away from the house.

Installing waterproofing on exterior walls will eliminate water from penetrating the walls and the exterior cove
area, preventing deterioration of foundation walls and securing the structural integrity of the foundation. See
EXTERIOR WATERPROOFING for more information on our advanced process. Hydrostatic pressure can
force water up from below the floor slab, where it is impossible to install waterproofing after the foundation walls
have been set on the footings and the floor slab is in place.

To prevent water intrusion from below the slab the best method is to have a perimeter drainage system properly
installed. The intent of the perimeter drainage system is to relieve the hydrostatic pressure. The groundwater is
pushed into the drain system and not into areas where it can damage carpets, walls, or belongings and become
the source of mold infestation.

The perimeter drain pipe can be placed around the entire building or a portion of the structure. Runs of drain
pipe also can be placed below the middle of the basement floor slab to relieve hydrostatic pressure under the
middle of the floor. The decision on how much drain pipe to install and where to install it is usually based on the
magnitude of the basement water problem.

One of the most important components of an interior perimeter drainage system is the sump pump. Barrier
Waterproofing Systems exclusively installs top of the line, battery back up, primary with secondary sump pump
systems in every interior drainage system. If the sump pump fails to work during a heavy downpour or power
outage, water could leak into the basement, so we never cut corners and cover all the bases. See INTERIOR
DRAINAGE for more information on our superior process.

Storm Water from the City Storm Water System Backing Up Into House

In many older houses with basements (mostly pre-1980), there is a perimeter foundation drain outside the
exterior wall, at the level of the basement floor, next to the footings at the time the house was built. A pipe was
usually installed from the perimeter foundation drain to the street where it was connected to the city storm sewer
system.

This can become a problem as the city storm sewer system becomes inadequately sized as more development
causes more rain runoff. When this happens, the rainwater in the sewer system can get so high that water flows
backwards toward the house. The perimeter foundation drain fills with water and releases large quantities of
water into the soil next to the footing and basement floor.

The soil becomes waterlogged and the water, which is under hydrostatic pressure, leaks into the basement. This
is a common problem and many cities have outlawed the practice of connecting perimeter foundation drains to
the city storm sewer system.

What should you do if you have this situation? Usually the proper installation of an interior perimeter basement
drainage system connected to a top of the line sump pump is the most practical and least expensive option. The
interior perimeter basement drainage system can usually pump the water out and onto the ground as fast as the
water is backing up from the city storm sewer system.

If that doesn’t take care of it, the other, more expensive alternative would be to dig up and cap the pipe that is
running from the house to the street from the perimeter foundation drain. However, this is not always possible
because many times, this pipe is also draining sanitary waste from toilets and sinks in the house.

If you believe you have this problem, contact Barrier Waterproofing Systems for help.

Sanitary Sewer Water from Municipal Sewer System Backing Up Into House

If the water is coming up through floor drains or sink drains in the basement, then the problem is likely water
backing up from the municipal sanitary sewer system. This usually occurs in older sections of some cities that
have combined sanitary and storm sewer systems. During heavy rains, combined sewer systems can become
overwhelmed with water. This can cause sewer water to back up in the system and sometimes into homes.

This creates a mess for most homeowners because it usually means they are getting other people’s fecal waste
backing up into their basement. To correct this, cities should update their sewer systems so the sanitary sewer
and storm sewer are running in separate pipes. Until this work is complete, the homeowner can install backflow
preventers that help stop sewer water from flowing backward into the house.

Unfortunately, because the city sanitary system works in conjunction with every house sanitary piping, the
backflow preventer usually cannot be located on the house’s main sewer line. It usually requires several backflow
preventers at all basement drain locations, such at every floor drain, every sink, and every toilet.

These backflow preventers require routine maintenance to make sure they are kept free of debris.

We hope that this information will help you make an informed decision with regard to a foundation drainage
system for your new or existing home. Keep in mind that in retrofit situations, years after construction, (when
landscaping, sidewalks, driveways, garages, porches, utilities, HVAC units, or even additions are in place), a
wide variety of techniques, sometimes quite different from new construction methods, are often the most
practical. Let us recommend a system which best meets your requirements.

Conclusion

Water in the basement is one of the most frustrating problems a homeowner can face. Most homeowner
insurance policies do not cover water damage from groundwater seepage or sewer back up. Some insurance
companies offer special coverage for this type of damage, but the type of items that are covered is usually very
limited.

Because much of the cost to replace damaged items and clean up the mess is not typically covered by
insurance or limited in coverage, much of the financial burden falls on the homeowner. Being prepared can help
prevent these types of water problems.

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