Foundation work comes with a vocabulary of its own, and most of it gets used in
estimates without much explanation. Here is what the terms mean, in plain language. If you
have an estimate in front of you with a word on it that is not here, call us at (865) 675-4177
and we will explain it.
- Atlas Resistance pier
- A brand of resistance pier installed beneath the footing to transfer a structure's load to deeper, more stable soil. Under footing bracket models are engineered for lifts of up to four inches, in diameters from two and seven eighths to four and a half inches, with capacities from thirty to seventy and a half kips.
- Bead board
- A panel installed against the inside of a basement wall during interior waterproofing. It gives moisture coming through the block a path down to the drain pipe beneath the floor instead of onto the finished surface.
- Bituthene
- An asphalt based waterproofing membrane supplied in rolls. During exterior waterproofing it is applied over a Blackjack coating, and it forms the actual barrier against water.
- Blackjack
- An asphalt coating rolled or brushed onto a foundation wall to seal the pores in the block. It is the first layer in an exterior waterproofing system, applied before the membrane.
- Bowing wall
- A foundation wall that has curved inward under pressure from the soil outside. Block walls are strong vertically but far weaker against a sideways push, so they bow at the middle and crack along a mortar joint.
- Carbon fiber band
- A strip of carbon fiber bonded flat to a foundation wall to hold a crack from widening. Used where a wall has cracked from hydrostatic pressure but has not displaced far. It takes up almost no floor space.
- Catch basin
- The collection box beneath a grate drain. Water and debris drop into it, so debris can be cleaned out rather than washing into the drain line.
- Clay soil
- Soil with a high clay content, common across Knox County. Clay swells as it takes on water and shrinks as it dries, and that repeated movement under a footing is a leading cause of foundation settlement in East Tennessee.
- Efflorescence
- The white, chalky mineral residue left on masonry after water passes through it and evaporates. Harmless in itself, but proof that water is moving through the wall.
- Encapsulation
- Sealing and insulating a crawl space so it is closed off from outside air and ground moisture. Both the sealing and the insulating are required; one without the other does not do the job.
- Also called a footing. The widened concrete base beneath a foundation wall or column that spreads the load across the soil. Piers and anchors work in relation to it.
- French drain
- A perforated pipe buried in the ground to collect water out of the soil and carry it away. Guardian installs four inch corrugated perforated pipe either wrapped in a soil separating sock and topped with gravel, or in the gravel free NDS EZ Flow form.
- Grate drain
- A surface drain with a visible grate over a catch basin, commonly set into a driveway to catch runoff before it reaches the house. Typically a four inch drain with a plastic or steel grate from four to twelve inches.
- Helical pier
- A pier turned into the ground like a screw, using helical plates to pull it down. Because it generates capacity through torque rather than pushing against the building, it suits lighter structures such as additions and porches.
- Hydroduct
- A protective flex board installed over the waterproofing membrane during exterior work, so gravel and dirt cannot tear the membrane when the trench is back filled.
- Hydrostatic pressure
- The pressure water in saturated soil exerts against a foundation wall. It is what pushes walls inward and forces water through cracks, and it is usually driven by poor drainage.
- I-beam
- A steel beam anchored to the slab below and bolted to the floor system above with half inch bolts, used to reinforce a below grade wall that has displaced more than about an inch. Guardian uses a W6 by 16 unless an engineer specifies otherwise.
- Interceptor drain
- Also called a curtain drain. A drain placed uphill of a structure to catch water moving across a slope before it reaches the building. Useful on the ridge and valley terrain common around Knoxville.
- Karst
- Landscape formed where water has dissolved limestone bedrock over long periods, leaving voids, cavities and sinkholes. Knox County sits in karst terrain, which means soil can migrate into a void and leave a footing with less support than it had.
- Kip
- A unit of force equal to one thousand pounds, used to state pier capacity. A pier rated at seventy kips can carry seventy thousand pounds.
- Manta Ray anchor
- The tie-back anchor system Guardian uses to stabilize bowing or tipping walls. Steel rods are driven into the substrate behind the wall until refusal, then set with a pneumatic piston that pulls the rod tight.
- NDS EZ Flow
- A gravel free french drain system using four inch corrugated perforated pipe wrapped in foam peanuts. It is crush proof, moves about thirty percent more water than a traditional pipe and gravel system, and is rated for a hundred year life span.
- Positive slope
- Ground that falls away from a foundation so water runs off rather than collecting against the wall. Restoring positive slope is often the least expensive drainage correction available.
- Push pier
- A pier driven straight down using the weight of the structure as resistance, until it meets soil that will carry the load. Guardian drives six inch by twelve inch concrete cylinders with number four rebar fed through them.
- Settlement
- Downward movement of a foundation as the soil beneath it compresses or washes away. Uneven settlement, where one part of a house drops further than another, is what produces stair-step cracks and sticking doors.
- Soil separating sock
- A fabric sleeve over a perforated drain pipe that keeps soil and sediment out of the perforations. Without it the holes silt up over time and the drain stops draining.
- Stair-step crack
- A crack in brick or block that climbs diagonally by following the mortar joints. It is a classic sign that one part of a foundation has settled further than the part beside it.
- Sump pump
- A pump set in a pit that collects water from a drainage system and moves it away from the house. It is what gives an interior drain somewhere to send the water it gathers.
- Swale
- A shallow, gently sloped channel shaped into a yard to gather surface water and carry it in a chosen direction. It works with the lay of the land and needs no pipe or hardware.
- Tie-back wall anchor
- An anchor that reaches out into stable soil beyond the pressure zone and holds a bowing wall from that side. Typically installed on four to six foot centers with steel C-channel, and the wall must be filled with concrete first.
- Vapor barrier
- Sheeting laid over the dirt floor of a crawl space to stop ground moisture rising into the space. It addresses ground moisture only, not humid air entering through vents.
- Vented crawl space
- A crawl space built with openings to the outside, on the standard practice that outside air would keep it dry. In a humid climate the incoming air is warmer and wetter than the crawl space, so moisture condenses underneath the house instead.
- Water table
- The level below which the ground is saturated. When it rises after heavy rain or snowmelt, it presses against basement walls and forces water through cracks that stay dry the rest of the year.
Common Questions
What is the difference between a footing and a foundation?
The foundation is the whole system that carries your house. The footing, or footer, is the widened concrete base underneath a foundation wall or column that spreads that load out across the soil. When someone says a pier was set beneath the footing, they mean beneath that base.
What does it mean when an estimate says kips?
A kip is one thousand pounds of force. It is used to state how much load a pier can carry, so a pier rated at thirty kips carries thirty thousand pounds. Pier capacities in the range of thirty to seventy and a half kips cover residential work comfortably.
Is a stair-step crack serious?
It is worth having looked at. A stair-step crack climbs diagonally through the mortar joints of brick or block, and it usually means one part of the foundation has settled further than the part next to it. Whether it is serious depends on how wide it is, whether it is still moving, and what is causing it.
Call us at (865) 675-4177 and we will talk through what you are seeing. The inspection and the estimate are both free.