footings shapes are made by
pouring concrete into a form
Form:
any framework containing wet concrete.
Forms can be made from:
any combination of steel, lumber, plywood.
Common footing forms are made with
2 x 4 lumber and braced to prevent them from being spread apart by the wet concrete. These boards are called haunch boards.
Spreaders, or form brackets:
The boards that hold apart the sides of the forms.
What nails are lumber formwork often assembled with?
Duplex nails because they make disassembly easier later on
A X should be formed in the top of the footing
Keyway
What does a keyway do?
Lock the foundation walls to the footing. It prevents moisture from seeping between wall and the footing.
Keyway is usually X” wide and Y” deep because Z
3 1/2” wide and 1 1/2” deep because a 2x4 is used to form it.
After the rebar has been positioned and the footings have been poured:
the tops of the footings should be troweled smooth.
Other load bearing structures such as columns and chimneys must
also be supported by footings.
Pier are X from foundation
Pilaster are Y from foundation
Pier are separate from foundation
Pilaster is part of it
A footing for a pier can be
round or sqaure
A pier is:
A block of column of concrete separate from the main foundation.
What is a pier used for:
often used to support girder floor systems or exterior decks.
What is sometimes anchored in a pier:
A steel pin or metal bracket is anchored in a pier to secure a wood post.
A pedestal on the pier should be X” above the finished basement floor and at least Y” above the finished grade in crawl-space foundations
3”
12”
When steel posts are used they are sometimes set X
If a concrete column is poured on top of a footing, Y
directly on the footing and concrete floor is then poured around them.
rebar placed vertically in the footing will keep the column in position.
How do you estimate the total rebar needed for a footing?
Stepped footings:
Footings that step down the sloped site.
When should the vertical step be poured in a stepped footing?
At the same time as the rest of the footing.
If the foundation wall is built with a concrete block, the height of the step should:
be in multiples of 8” because this allows the height of a block with a standard 3/8” mortar joint.
Step footings are set for sloping lot min X” below grade
min 42 in below grade.
The bottom of a step footing is always placed on X
undisturbed soil below frost line.