Concerns about cracks
Cracking is a frequent cause of concern in the concrete industry - especially when it appears
in a newer homeowner’s foundation. This section is to briefly help explain why cracks occur,
and when a crack should, or shouldn't be a concern.
Cracks in concrete walls - just as in floors, sidewalks, and driveways - are a common
occurrence. A common adage is that there are two guarantees with concrete: 1) It will get
hard, and 2) It will crack.
That isn't exactly what homeowners – especially newer ones - want to hear, but there is good
news! Although cracks can not always be completely prevented, they can be reduced or
controlled to some extent. Another consoling fact for homeowners is that the majority of
reported cracks are no cause for alarm.
in a newer homeowner’s foundation. This section is to briefly help explain why cracks occur,
and when a crack should, or shouldn't be a concern.
Cracks in concrete walls - just as in floors, sidewalks, and driveways - are a common
occurrence. A common adage is that there are two guarantees with concrete: 1) It will get
hard, and 2) It will crack.
That isn't exactly what homeowners – especially newer ones - want to hear, but there is good
news! Although cracks can not always be completely prevented, they can be reduced or
controlled to some extent. Another consoling fact for homeowners is that the majority of
reported cracks are no cause for alarm.
SOLID FOUNDATIONS INC. - Your Complete Poured Foundation Contractor
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There are many different factors that can play a part in concrete cracking - some within reasonable control of the concrete
contractors, some that are not:
Like with other materials, concrete cracks will follow the “path of least resistance”, therefore, it is fairly common for
shrinkage and temperature cracks to appear at the corner of a window, beam pocket, or other opening.
Unless these cracks are leaking, or showing signs of significant lateral displacement (movement of approx. 1/4” or more),
they are usually of no structural concern, and are not normally covered under warranty (see “Notice on Warranty Coverage”
section below).
contractors, some that are not:
- drying shrinkage
- thermal contraction or expansion
- nearby disturbances such as land erosion, quarry blasting, heavy construction or demolition, etc.
- surrounding soil conditions
- settlement or expansion of the sub-grade
- hydrostatic pressure from water saturation
Like with other materials, concrete cracks will follow the “path of least resistance”, therefore, it is fairly common for
shrinkage and temperature cracks to appear at the corner of a window, beam pocket, or other opening.
Unless these cracks are leaking, or showing signs of significant lateral displacement (movement of approx. 1/4” or more),
they are usually of no structural concern, and are not normally covered under warranty (see “Notice on Warranty Coverage”
section below).
Some Common Causes of Cracks
Methods Used to Limit / Reduce Cracking
Although some of the contributing factors of cracks are outside of the building contractor’s control, we at Solid Foundations
Inc. consistently take the most effective, reasonable control measures to assure that our foundations – your foundation - will
have the smallest, and least amount of cracks possible.
If a small crack should appear, these methods also assure the greatest chance of limiting or controlling further expansion of
the cracks.
These control measures include, but are not limited to:
Inc. consistently take the most effective, reasonable control measures to assure that our foundations – your foundation - will
have the smallest, and least amount of cracks possible.
If a small crack should appear, these methods also assure the greatest chance of limiting or controlling further expansion of
the cracks.
These control measures include, but are not limited to:
- recommending to the builder/customer the adequate thickness and depth of footers for the area and soil conditions
- the proper concrete mix design: proper amount of water, type and amount of cement, aggregates, etc.
- adequate steel reinforcement bar according to each area’s building code and soil conditions
- insulating the concrete when extreme temperature swings are forecast
- proper, and careful backfilling
What if a Crack is Leaking?
If a crack has shown signs of moisture or water seeping through into the basement area, a
“flush-test” is usually the best method to determine whether the leak is occurring above, or
below, the grade of the waterproofing.
If it is determined that the source of the leak is below the grade of the waterproofing, it could
mean that the waterproofing has failed, and that the crack may need to be injected from the
inside of the basement (see "Injecting a Crack" section below). Although this is sometimes
the case, it is more often found that the leak originates from the exposed exterior crack above
the waterproofing grade.
If it is determined that a leak originates above the waterproofing, a silicone-based sealant is
used to seal the outside of the crack from the waterproofing to the top of the exposed
foundation wall, keeping any further water from entering the crack.
“flush-test” is usually the best method to determine whether the leak is occurring above, or
below, the grade of the waterproofing.
If it is determined that the source of the leak is below the grade of the waterproofing, it could
mean that the waterproofing has failed, and that the crack may need to be injected from the
inside of the basement (see "Injecting a Crack" section below). Although this is sometimes
the case, it is more often found that the leak originates from the exposed exterior crack above
the waterproofing grade.
If it is determined that a leak originates above the waterproofing, a silicone-based sealant is
used to seal the outside of the crack from the waterproofing to the top of the exposed
foundation wall, keeping any further water from entering the crack.
Notice on Warranty Coverage
Crack injection repairs for leaks due to a failure of the waterproofing, that are still covered by the existing waterproof
warranty, also include cosmetic repairs, as needed. Note: Minor (non-structural) cracks that are not showing signs of
leakage are not a serious concern, and are not covered by warranty. If you would like to make a warranty claim for a crack
that is leaking, please fill out the "File a Warranty" form below - or click here to find out other ways to contact Solid
Foundations Inc.
warranty, also include cosmetic repairs, as needed. Note: Minor (non-structural) cracks that are not showing signs of
leakage are not a serious concern, and are not covered by warranty. If you would like to make a warranty claim for a crack
that is leaking, please fill out the "File a Warranty" form below - or click here to find out other ways to contact Solid
Foundations Inc.
Injecting a Crack
If a crack is leaking below the grade of the waterproofing, a crack injection repair may be
necessary.
The first step in this process is to drill holes along the inside of the crack, to insert plastic
“injection ports”.
Next, a temporary two-part epoxy is mixed and spread along the length of the crack, and
around the ports, making as complete a seal as possible from the top to the bottom of the
crack.
When the temporary epoxy sets up firmly, a special liquid polyurethane foam or epoxy
(depending on the size of the crack) is injected into the ports. As the crack is filled, bottom
to top, the ports are capped off to contain the foam. As the foam expands to completely fill
the crack, any water still in the crack is forced out, then when the foam completely sets and
hardens, it creates a seal that prevents any more water from entering the crack and
causing problems.
necessary.
The first step in this process is to drill holes along the inside of the crack, to insert plastic
“injection ports”.
Next, a temporary two-part epoxy is mixed and spread along the length of the crack, and
around the ports, making as complete a seal as possible from the top to the bottom of the
crack.
When the temporary epoxy sets up firmly, a special liquid polyurethane foam or epoxy
(depending on the size of the crack) is injected into the ports. As the crack is filled, bottom
to top, the ports are capped off to contain the foam. As the foam expands to completely fill
the crack, any water still in the crack is forced out, then when the foam completely sets and
hardens, it creates a seal that prevents any more water from entering the crack and
causing problems.
Cosmetic Finish
After the polyurethane foam or epoxy completely sets, the temporary epoxy and injection
ports are removed. The surface at the crack is then cleaned and prepared, and an
architectural grade cement mixture is applied to cosmetically repair the surface, blending it
in as much as possible with the pattern and texture of the original wall.
When the job is completed, and the repair dries completely, it is usually difficult to
determine exactly where the crack was located. Over time, any slight differences in color
between the original wall and the newly repaired section should also become less
noticeable.
If there are any further questions or concerns, or if the problem should get significantly
worse in the next several months, please feel free to contact us. We will do our best to
answer your questions and/or find a satisfactory resolution to your concerns.
ports are removed. The surface at the crack is then cleaned and prepared, and an
architectural grade cement mixture is applied to cosmetically repair the surface, blending it
in as much as possible with the pattern and texture of the original wall.
When the job is completed, and the repair dries completely, it is usually difficult to
determine exactly where the crack was located. Over time, any slight differences in color
between the original wall and the newly repaired section should also become less
noticeable.
If there are any further questions or concerns, or if the problem should get significantly
worse in the next several months, please feel free to contact us. We will do our best to
answer your questions and/or find a satisfactory resolution to your concerns.
