Foundation Systems

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Foundation Systems
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What Does the Foundation System Do?

• Support the load or weight of the house and
  transfer it to solid ground
• Repel water that may accumulate in the ground so
  that the basement stays dry and healthy
• Anchors the house solid to the ground

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Major Components of a Foundation System

• Strip (or Wall) Footing
• Column Footing
• Foundation wall
• Column or Pier
• Weeper or Drainage Pipe
• Basement Floor

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The Make up of a Foundation System

• Step 1 - Excavation
• A cut, cavity, trench, or depression made by
  removing earth. Excavations are dug to prepare
  the site for footings, foundations, and the
  installation of pipes for site drainage.

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The Make up of a Foundation System

• Step 2
• Forms are constructed on the undisturbed soil at
  the bottom of the excavation. It might look like
  this

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Key Terms

• Form
• Any framework designed to contain wet concrete.
  Forms can be made of steel, lumber, or a
  combination of lumber and plywood.
• Footing
• A base providing a larger bearing surface against
  the soil for load bearing parts of the structure.
  Footings are generally made of concrete poured
  into place.

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Key Terms

• Keyway
• The part of a footing that locks the foundation
  walls into the footing. Usually a groove cut
  into the top of the footing.
• Rebar
• Reinforcing steel rods that are embedded into
  concrete to make it stronger. Rebar has a
  patterned surface that makes it bond to concrete.

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The Make up of a Foundation System

• Step 3
• The foundation wall is constructed on top of the
  footings once they are fully cured. Foundation
  walls may be constructed out of concrete, block
  or even pressure treated wood

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Key Terms

• Foundation Wall
• The wall that sits on the footing and transfers
  the load of the house from the mudsill down to
  the footings. Basically the foundation walls are
  the basement walls.
• Anchor Bolt
• A bolt, usually L shaped that is embedded into
  the foundation wall. It is used to securely
  fasten the sill plate to the foundation.

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The Make up of a Foundation System

• Step 4
• The drainage system or weepers are installed.
  This consists of a large perforated pipe that
  runs around the outside of the perimeter of the
  house, beside the footing. It is buried in
  gravel and covered with a landscape fabric. The
  outside of the foundation wall is covered in a
  waterproofing membrane that is designed to direct
  any water down to the drainage pipe and safely
  away from the house.

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Key Terms

• Weepers
• Perforated drainage pipe installed around the
  perimeter of the house, designed to capture any
  water accumulating near the foundation and drain
  it safely away, either to the municipal storm
  sewers or to a sump pump installed inside the
  house.
• Waterproofing Membrane
• Plastic membrane installed on the outside of the
  foundation, below the finished grade, or ground
  level. The membrane does not make a waterproof
  seal itself, it just acts as part of the
  waterproofing system by creating a path of least
  resistance for water to travel easily to the
  weeper pipe and therefore safely away from the
  house

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The Make up of a Foundation System

• Step 5
• Backfill. Once the water proofing system is in
  place and after the floor has been framed,
  (depending on the foundation type) the excavation
  is backfilled. Any portion of the hole that was
  excavated, that is not now occupied by the
  foundation gets filled back in. Typically the
  same soil that was removed during excavation is
  used for backfill. The backfill is then graded
  to ensure that water is not allowed to accumulate
  near the house.

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Key Term

• Backfill
• The process of filling the unused portion of the
  excavation around the house back in. It is
  important to ensure that proper grading is
  maintained when back filling.

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The Make up of a Foundation System

• Step 6
• Pour the basement floor. Once the drains have
  been installed in the basement, the area up to
  the top of the footings is filled with gravel,
  and then a concrete floor is poured on top of
  that.