Your browser appears to be outdated. This website may not display correctly!

Information Pages

In the interest of minimizing confusion we offer the following definitions.


Diagram of typical foundation

 

Foundation Terminology

The footing portion supports the load or weight of the structure.

The stemwall keeps soil from falling into the structure and gives a surface on which to build or frame the structure.

The reinforcing steel acts structurally to give tensile strength to the footing and stem wall.

1 to 1 Ratio:
The “angle of repose” of common soils. Many jurisdictions allow 1 to 1 or 12” of vertical drop per 12” of horizontal travel for NON-load bearing slopes. Load bearing slopes are spec'd at a 2 to 1 Ratio.
2 to 1 Ratio:
The ratio of a horizontal distance to drop which has been ruled as necessary to support a residential building load. The interior piers or supports under a home must be 2 to 1 away from an adjacent step in grade. In other words, a bearing pad must be no closer than 4 feet to a 2 foot drop.
ADA Accessible:
A home designed/built for wheelchair access. Special provisions need to be made to provide a home with ADA access. A design path must be established prior to excavation. Excavation and foundation grades are critical to ADA access.
Air entrainment:
Percentage of air present in the concrete admixture. Concrete exposed to weather extremes must be air entrained.
Anchor Bolt:
Bolts which fasten the wood framing to the foundation. An anchor bolt is a hold down component. Anchor bolts are used in conjunction with plate washers and brackets to fasten the structure to the foundation. Commonly found and used in sizes from ½”x8” to 1¼”x48” and all sizes in between. See also bolt retrofitting.
Backfill:
Backfill is the soil around the structure which covers the stemwall. Backfill must be 12”-18” deep to conform to frost code.
Bearing Capacity:
The ability of the native soil OR a compatible fill material to support a structure. See also 2 to 1 ratio.
Cant or Chamfer Strip:
Strips of wood used to form vertical lines in the wall for crack control. Also used to chamfer edges on decorative retaining walls.
Center Pier:
The short section of concrete wall between multiple garage doors.
Cheap:
Often describes the lowest bidder on any project. Most often “cheap” means only that you'll pay more later.
Code:
The governing agency relevant to your area. Clark County, WA, uses WAC; a combination of IRC, UBC, and IBC. For a listing of some code sections relevant to foundations, click here.
Damp Proofing:
The act of coating a foundation wall with a tar-like emulsion or other membrane in an attempt to keep moisture from occurring on the inside or structure side of a concrete wall. Damp proofing is the minimum requirement for treating a concrete basement wall. We guarantee our basements to be dry provided you follow our cost-effective construction path.

Daylighted (basement):
A basement which allows one to walk directly out into the yard. Special provisions must be made so that daylighted areas meet frost code. We have strong opinions regarding properly daylighting a basement; call for details. Also see daylight basement drawing (right).

Engineered:
This means that a houseplan or set of blueprints need be analyzed for resistance to loading failures and a design path be decided upon and detailed by a licensed structural engineer. Architects, designers and home design books DO NOT normally qualify to meet the standards required by local jurisdictions.
Foundation Forms:
We primarily use the Rapi-Form system of reusable fiberglass faced HD plywood. Our forms come in 24” height increments and allow us to pour walls as tall as 26 feet. Another option is the Styrofoam ICF or Insulated Concrete Form which stays in place on the job. Other options exist and we can “face” or line our forms for crack control and decorative facing (see our gallery). We can also line our forms with styrofoam if one is sold on the "ICF concept" but is deterred by the high cost of ICF forms.
Frost Code:
Building code dictates that a structure must have 12”-18” of backfill or cover over the structural footings so that frost doesn't penetrate the ground and heave or lift the structure. Often garages and daylighted basements are trench-dug so that they can meet frost code.
Garage Return:
The section of wall between the edge of the garage door and the edge of the garage itself. Most often points of concentrated loading; these are nearly always engineered.
Haunched:
A haunched edge on a slab is a thickened edge. The thickened edge is added as a footing support to carry the weight of the building.
Hold Down:
Sometimes abbreviated HD. Also spelled holdown. Hold downs fasten the structure to the foundation. Often used by licensed engineers to transfer stresses or loads down into reinforced stress collectors in the foundation.
Hub and tack:
see layout
ICF Forms:
Insulated Concrete Forms. We do Styrofoam forming and can use any of the many systems available. We do not recommend ICF nor try to sell it. Call Al at (360) 904-6941 for details.
Inspections:
We are required to have our formwork inspected by the local building department. Inspections commonly required include: setback, reinforcing steel, foundation forms. Erosion control measures are also evaluated at this stage; measures must be properly in place or job may be shut down. In Cowlitz County it is also required that the drain field be marked out with flagging tape for work to continue.
Layout:
The act of “laying out” or marking the outline of the building on the ground. Layout is done either by us or by a surveying company. Also called “hub and tack.” Initial lot layout and layout for excavation is normally done by the builder. We can do it for a fee.
Lift:
Our concrete forms come in 24” increments and are designed to be stacked to appropriate height. Each 2’ increment is called a lift.
Moisture Barrier:
see damp proofing.
Mono-pour:
A forming system which allows pouring footing and stem walls at the same time.
Monolithic slab floor:
A slab floor with thickened edges or "haunches" for support. Read more...
Mud sill:
See sill plate
Pockets:
Cutouts in the concrete wall sized to accept joists or beams for support. Commonly used in ADA Accessible homes.
Pour line:
The visible seam or line which results from pouring fresh concrete over cured or partially cured concrete.
Pre-hang, pre-hung:
(see also wet-set) Some jurisdictions require that reinforcing steel, anchor bolts and tie-down brackets be pre-hung for inspection; this results in extra charges.
Prescriptive Path :
“Prescriptive Path” is a design model which allows a builder or designer to build to a prescribed path or, in other words, using existing rules of structural design. Read more...
Pricing Schedule (Builder):
Licensed professional home builders are entitled to both volume and efficiency discounts from our Standard Pricing Schedule
Pricing Schedule (Standard):
Our current retail pricing structure without any volume or efficiency discounts. Licensed home builders and clients showing expertise in the construction fields will realize significant savings over these retail prices. Click here to view!
Reinforcing Steel:
Steel bars cast into place within the poured concrete footings and walls. It is commonly stated that “the rebar gives the strength and the concrete is only there to contain and cover the rebar.” This is essentially true. Reinforcing steel, or "rebar," is the material which gives poured concrete its tensile strength or resistance to deflection (bending). Rebar is sized in "eighths" which means that #4 bar is 4/8 or four eighths diameter. Reduced, this becomes 1/2". #4 bar is 1/2", #5 bar is 5/8", and #6 is 3/4" nominal diameter. Structural reinforcing steel is produced by stuffing wire through a roller so that ribs are formed on it. These ribs, when poured into the concrete matrix, grip in such a way that the bar will stretch and break under tension instead of slipping and pulling out. We at Sierra Concrete use only "60 grade" rebar. 60 grade is reinforcing steel which has been tempered, and graded or selected based on tensile strength. 40 grade or "barnyard bar" is un-graded which means that it varies in strength but is generally not tempered.
Retaining Walls:
From an engineering standpoint any wall which keeps material from an area is a retaining wall—even a short footing and stemwall around a crawlspace is keeping your yard out of your crawlspace. That said, those walls which we typically refer to as retaining walls are those walls over 48” tall or showing unbalanced fill of more than 48”. Retaining walls which retain or hold back 48” or more of material must be structurally engineered so that they don’t tip over. This engineering will show a widened footing, use of angles or corners or sometimes a buttress or tie-back wall. Retaining walls showing as much as 10 ’ of unsupported wall may be covered under prescriptive path engineering. Retaining walls generally fall into 1 of 2 categories, restrained and unrestrained, or free-standing (see images to the right). Read more...
Rock Pocket:
A situation which occurs when concrete placement is disrupted by conditions such that the rocks are separated from the cementitious admixture. Rock pocketing can be structural or only cosmetic. Structural deficiencies occur when pocketing exceeds a depth of ½ aggregate diameter. Pocketing of less than aggregate diameter (½” - ¾”) is considered to be cosmetic and need only be addressed if it affects appearance. We strive to avoid ALL rock pocketing and are successful most of the time.
Setback:
Legal distance from a property line. This distance varies by area, even by address. Setbacks can change within subdivisions.
Sill plate:
A strip of pressure-treated lumber which must be present at any interface between wood framing and concrete.
Slump:
Consistency or viscosity of concrete material.
SSTB:
A structural hold down component.
Stacked wall:
Any foundation wall over 24” tall.
Steps:
Steps are divided into 3 main subsections. “Steps in subgrade” result in a step in the footing, a break in the forms and possibly a step in the wall grade or framing surface. Billable steps are: steps in footing, steps in wall and steps in forms. Some jurisdictions require that steps in footing be “boxed” which means that the footing must continue unbroken down over the step in grade.
Strap:
Hold down strap. A hold down which is self-contained, poured into the concrete.
Subgrade:
The excavated portion which the structure bears on. Subgrade must be undisturbed soil or compacted fill material. For compacted material to pass building code it must be termed “compacted buildable fill” with an engineer’s stamp of approval. We at Sierra Concrete will not knowingly build on compacted fill with the exception of occasionally “bridging” a short section like a ditch.
Sweeps:
Sections of Schedule 40 electrical conduit which are “swept” or bent 90 degrees in a gradual curve. A swept 90 will have a radius of 72 diameters or more to allow passage of a stiff cable.
Trench digging:
The method of digging footings into the ground instead of pouring them right on the subgrade.
Vapor Barrier:
A layer of visqueen plastic or other membrane which protects against water vapor intrusion. Not to be confused with waterproof or waterstop.
Vents:
It is required that crawlspace foundations be vented at the rate of 144 square inches airflow per 150 square feet building area. This ratio of 144 square inches/150 square feet is not actually “code required.” Actual code requires that the site be assessed for moisture content and drainage and the 1 square foot/150 square feet rating is a “worst case scenario” or a 10 on a sliding scale of 1 to 10 with 10 being the wettest. Assessment is expensive so generally using the figure of 1’/150’ is the path of least resistance or the least expensive way to go.
Waterstop Wall:
A wall or a footing and wall which is purported to be watertight or proof against liquid water intrusion. (see also vapor barrier)
Wet-set:
The act of inserting rebar or tie-downs into the unhardened concrete matrix.