Foundation walls

The following is a list of recommendations that builders can use to utilize the foundation as a mechanical barrier to radon entry. Foundation walls and floor slabs are often constructed of poured concrete. Plastic shrinkage, and therefore cracking, is a natural function of the drying process of concrete. Many factors, such as the water/cement/aggregate ratio, humidity, and temperature, influence the amount of cracking that occurs in a poured concrete foundation. Cracking may be minimized by... 

There are geographic areas throughout the United States in which the majority of foundation walls are poured concrete and other areas where masonry walls predominate. Poured concrete walls are generally available only in areas where contractors have the in-house expertise to build them and either rent or have invested in reusable forms. In areas where both types of construction are found, the costs of each seem competitive. 

The perimeter crack is located between the edge of the floor slab and the foundation wall. This applies to slabs in basements, crawlspaces, and slab-on-grade foundations. As a cold joint, this perimeter crack is always a potential radon entry point. Contractors building radon-resistant houses... 

Every house has some minimum penetration through the slab or foundation walls. The ones always present are water pipe entry and sewer pipe exit. Common additional penetrations are floor drains, sump holes, and air conditioner condensate drains. 

The most common dampproofing treatment for residential foundation walls is a parge coat covered with bituminous asphalt. The parge coat is used for concrete masonry walls but is not necessary for poured concrete walls. This two-stage treatment has been replaced by surface bonding cement in some areas. 

Soil that has been excavated from the basement is commonly used as backfill against foundation walls. This should not be the case where the site material contains clays and silts, particularly organic clays and silts. If local soils are not appropriate, the builder may use gravel to backfill. 

NCMA, Concrete Masonry Foundation Walls, National Concrete Masonry Association, NCMATEK 43, Herndon, VA, 1972. 

Underground steel service lines, when installed below grade through the outer foundation wall of a building, shall be either encased in a sleeve or otherwise protected against corrosion. The service line and/or sleeve shall be sealed at the foundation wall to prevent entry of gas or water into the building. 

The walls of crematoria IV and V, which were built entirely above ground, were of simple brick masonry. After they were blown up, both buildings were demolished to their foundation walls and concrete foundations. The foundation wall of crematorium V, which is approximately 1 m high, is supposed to have been rebuilt.293 The foundation wall of crematorium IV, which is approximately 50 cm high, is also supposed to have been rebuilt out of other rubble at a later time.56... 

A series of test excavations were performed at the place where the [gas] chambers had to have been, in order to find their foundation walls if possible. Pits 10-15 meters in length and 1.5 meters deep were dug. Undisturbed strata of earth were revealed by this. 

Block out- To install a box or barrier within a foundation wall to prevent the concrete from entering an area. For example, foundation walls are sometimes "blocked" in order for mechanical pipes to pass through the wall, to install a crawl space door, and to depress the concrete at a garage door location. 

Brick ledge- Part of the foundation wall where brick (veneer) will rest. 

Caisson- A 10" or 12" diameter hole drilled into the earth and embedded into bedrock 3-4 feet. The structural support for a type of foundation wall, porch, patio, monopost, or other structure. Two or more "sticks" of reinforcing bars (rebar) are inserted into and run the full length of the hole and concrete is poured into the caisson hole... 

Cantilever- An overhang. Where one floor extends beyond and over a foundation wall. For example at a fireplace location or bay window cantilever. Normally, not extending over 2 feet. 

Clip ties- Sharp, cut metal wires that protrude out of a concrete foundation wall (that at one time held the foundation form panels in place). 

Concrete- The mixture of Portland cement, sand, gravel, and water. Used to make garage and basement floors, sidewalks, patios, foundation walls, etc. It is commonly reinforced with steel rods (rebar) or wire screening (mesh). 

Counterfort- A foundation wall section that strengthens (and generally perpendicular to) a long section of foundation wall... 

Crawl space- A shallow space below the living quarters of a house, normally enclosed by the foundation wall and having a dirt floor. 

Dampproofing- The black, tar like waterproofing material applied to the exterior of a foundation wall. 

Drain tile- A perforated, corrugated plastic pipe laid at the bottom of the foundation wall and used to drain excess water away from the foundation. It prevents ground water from seeping through the foundation wall. Sometimes called perimeter drain. 

Expansion joint- Fibrous material ( l/2" thick) installed in and around a concrete slab to permit it to move up and down (seasonally) along the nonmoving foundation wall. 

Footer, footing- Continuous 8" or 10" thick concrete pad installed before and supports the foundation wall or monopost. 

Foundation ties- Metal wires that hold the foundation wall panels and rebar in place during the concrete pour. 

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