Footers Flashcards
What is a footer?
An enlarge net extension of the foundation which desperses the weight of a structure into the ground.
What does PSI mean?
Pounds per square inch
what is the standard psi concrete strength in your area for footers?
2500 psi
what is the acceptable percentage of calcium that can be added to concrete during cold conditions?
2%
How do you calculate how many cubic yards of concrete needed in a footer?
1) concert inches into feet (8”/12’) 2) LxHxW 3) convert to Cubic Yards: divide LxHxW by 27
When and where do you use a footer bulkhead?
Changes in elevation. example: walkouts or townhouse steps
Why do we use footer bulkheads?
holds weight when change in elevation
Do you need extra concrete for footer bulkheads?
Yes
What is rebar?
steel bar that adds extra strength and support to concrete
what is the diameter of #4 Rebar?
1/2”
what is the diameter of #7 Rebar?
7/8”
what is a stanchion pad?
concrete pier used to support a stanchion post.
How do you determine the thickness of a stanchion pad?
Standard 24”x24” by 12” depth
Grade beam
horizontal load bearing foundation
floating footer
unformed footer used when poor soil conditions exist. it is usually wider and has rebar
conventional footer
footer that is formed and trenched
underpinning a footer
is a method used to increase footer strength and depth.
On unstable ground, at what point would you convert from using sub grade block to a grade beam?
Once you hit frost level and there isn’t good soil.
frost line
depth of frost footer (24”)
what is the minimum forst line in your area?
24”
what is the elevation of a stanchion pad in relation to the top of the footer?
1” below footer
what is the maximum tolerance for a footer to be out of square and out of level in your market/
1/2” square and 1/4” level
within what time period should the footer forming material be removed?
24 hours
where should any excess concrete be unloaded?
6 mil poly
what is a keyway?
groove in footer designed to provide a channel for concrete to tie into. 3 1/2”W and 1 1/2” deep
what mix concrete do you use for a footer in your area?
2500 PSI
How do you check a footer to ensure its squareness?
Pull diagonals on foundation plan
