Home Inspection Glossary: Caisson ===> Catch Basin
Caisson
A deep foundation element formed by drilling a large-diameter hole into the earth and filling it with concrete and reinforcing steel. Caissons are designed to transfer structural loads to stable soil or bedrock well below the surface. They are typically used when surface soils are weak or expansive, and are often found beneath porches, decks, raised patios.
In residential construction, caissons are usually not visible during a home inspection, as they are buried below grade. However, their presence may be inferred based on visible features such as:
• Elevated structural piers
• Oversized post bases
• Exposed grade beams or footings on sloped lots
Inspectors should be aware of caisson use when evaluating settlement concerns, structural supports, or permitted structural additions.
Related Terms: Grade Beam, Foundation, Pier, Structural Settlement
Calibrate
To adjust a tool or instrument so that its readings are accurate and consistent with a known reference or standard.
Inspector's Note: Inspectors who perform radon testing, gas detection, combustion analysis, or indoor air quality assessments must ensure that their instruments are properly calibrated according to manufacturer guidelines and—where applicable—regulatory requirements. A miscalibrated tool can lead to false readings, improper conclusions, and potential liability.
Calibration should be verified at regular intervals and documented. Some tools may require professional calibration by a certified lab, while others allow field calibration or bump testing. Calibration: The process of adjusting an instrument to ensure that its readings are accurate when compared to a known standard. Calibration is required at regular intervals for many precision tools used in specialty inspections.
While calibration of household equipment is beyond the scope of a standard home inspection, inspectors using instruments such as radon monitors, gas detectors, or IAQ sensors are responsible for ensuring those tools are properly calibrated. Failure to follow manufacturer or regulatory calibration requirements may affect test validity and legal defensibility.
Related Terms: Calibrate, Radon Monitor, Gas Detector, Indoor Air Quality Testing, Specialty Inspection
Canopy
A roof-like structure that projects beyond the exterior wall of a building. Canopies typically providing shelter over a door, window, walkway, or loading area. Canopies may be supported by brackets, posts, or they might be cantilevered from the structure.
Inspector's Note: Inspectors should check for proper support, secure attachment, signs of water intrusion at wall penetrations, and any evidence of settlement or rot in structural elements.
Related Terms: Portico, Port Cochère
Cant Strip
A beveled support installed at the junction between a flat roof and a vertical surface, such as a parapet wall. It creates a gradual transition to prevent sharp angles that can stress roofing membranes, helping to reduce cracking or splitting at that intersection. Typically used beneath base flashing in built-up or modified bitumen roofing systems.
Inspector's Note: While often concealed, the absence of a cant strip can contribute to membrane failure at roof-to-wall transitions. Sharp 90° angles in flat roofs are a red flag for potential long-term deterioration.
Cantilever
A structural element that projects beyond its support and is anchored only at one end. Common examples include bay windows, floor overhangs, and balconies.
Inspector's Note: Cantilevered structures should be evaluated for proper support, water management, and insulation. Watch for sagging, rot, or thermal bridging—especially where floors extend past the foundation.
Related Terms: Beam, Ledger, Soffit
Cantilevered Void
A trapezoid-shaped cardboard or foam form placed beneath a concrete foundation to create a gap between the soil and the slab. Used in areas with expansive clay soils, the void allows the soil to swell without lifting the structure.
Inspector's Note: Often found in post-tensioned or slab-on-grade foundations in regions with expansive soil. While usually concealed, signs of improper soil movement, cracking, or structural shifting may indicate failure of the void system.
Related Terms: Expansive Soil, Void Form, Slab-on-Grade
Cap
The decorative or protective topmost part of a column, pilaster, newel post, or molding. Also used on fence posts or wall ends.
Inspector's Note: While mostly aesthetic, caps can protect the tops of exterior wood elements from water damage. Look for signs of rot, missing caps, or poorly sealed joints.
Related Terms: Trim, Pilaster, Post
Cap Flashing
A type of flashing attached to a vertical surface that overlaps base flashing below it, preventing water from migrating behind the base flashing. Also called counter flashing.
Inspector's Note: Common around chimneys and roof-wall intersections. Ensure it’s properly sealed, overlaps the base flashing, and is not pulling away from the wall.
Related Terms: Base Flashing, Counter Flashing
Cap Sheet
The top layer in a built-up roofing (BUR) system, typically coated with minerals or granules to resist UV damage and weathering.
Inspector's Note: On flat or low-slope roofs, inspect cap sheets for blistering, cracking, or delamination. Improper repairs or ponding water can shorten their lifespan.
Related Terms: Built-Up Roof, Modified Bitumen
Cap Sheets
Layers of felt or fiberglass membrane bonded with bitumen and laid over an existing roof, typically as part of a repair or restoration process. Not to be confused with the cap sheet of a built-up roofing system.
Inspector's Note: Found in roof overlays and sometimes misused as a shortcut for full replacement. Look for edge lifting, incomplete sealing, or signs of moisture trapped below.
Related Terms: Roof Overlay, Modified Bitumen
Cape Chisel
A narrow, flat chisel used to clean out mortar joints between bricks, typically in preparation for repointing.
Inspector's Note: While not commonly used by inspectors, knowing the tool helps when describing repair techniques or explaining what masonry contractors may do to correct deteriorating mortar joints.
Related Terms: Tuckpointing, Mortar, Brick Veneer Carbon Monoxide: A colorless, odorless, and deadly gas produced by the incomplete combustion of fuels such as natural gas, propane, oil, or wood. Abbreviated as CO.
Inspector's Note: Inspectors should check for proper venting of fuel-burning appliances and the presence of CO alarms where required by local codes. Even when outside the standard, inspectors often report missing or faulty CO detectors as a safety concern.
Related Terms: Combustion Air, Draft, CO Detector
Carport
A roofed structure designed to provide shelter for vehicles, typically open on one or more sides. Unlike a fully enclosed garage, a carport lacks walls and may be freestanding or attached to the main structure of a home.
Carports are commonly built with:
• Wood or metal framing
• Pitched or flat roofs
• Concrete slabs or gravel bases
Carports may or may not be permitted structures, and some have been enclosed after construction, potentially without required approvals.
Related Terms: Garage, Porch Roof, Ledger Board, Foundation Settlement, Flashing
Cartridge Valve
A type of plumbing valve that uses a replaceable cartridge to control water flow and temperature. Cartridge valves are commonly found in single-handle faucets, where a single lever regulates both hot and cold water. The cartridge contains internal seals and mechanisms that allow smooth operation and easy replacement.
Inspector's Note: Dripping or stiff faucet handles may indicate a worn or faulty cartridge. Replacement is typically straightforward and does not require removing the entire faucet.
Related Terms: Mixing Valve, Faucet, Shutoff Valve
Casement Window
A window with a sash that is hinged at the side and swings open like a door. Casement windows are typically operated with a crank or lever handle and open outward, although inward-swinging designs exist in older or European homes. The sash presses against weatherstripping when closed, providing a tight seal.
Inspector's Note: Older casement windows may lack cranks and instead use a lever or latch to open and close the sash manually. These systems often rely on friction stays or manual hold-open hardware. Some inspectors refer to casement windows as “crank windows” in conversation, especially with clients. However, using the term casement in reports provides greater precision.
Related Terms: Awning Window, Hopper Window, Window Operator, Sash
Casing
Casing refers broadly to the trim or molding that finishes the perimeter of an opening, such as a window, door, attic hatch, or mechanical access panel. It conceals the gap between the rough opening and wall surface, and provides a visual transition between building elements. Casing styles vary by region and era and can offer clues to a home’s age or remodeling history.
Inspector's Note: Damage to casing, such as staining, separation from the wall, or buckling may indicate underlying moisture intrusion, settlement, or deferred maintenance.
Related Terms: Window Trim, Door Trim, Jamb, Scuttle
Casing (Window and Door Trim)
Trim or molding used to finish the perimeter of a door or window opening where it meets the wall surface. Casing covers the gap between the rough opening and finished surface, concealing framing irregularities and providing a visual transition. It is most commonly found around doors and windows, but also surrounds attic scuttle openings, crawlspace hatches, and mechanical access panels throughout a home. Materials vary from wood and MDF to PVC and composites, with styles ranging from plain to ornate.
Inspector's Note: Casing is a finish detail, but its condition can offer early clues about more serious underlying structural issues.
Related Terms: Jamb, Sill
Cast-Iron Pipe (Plumbing)
A type of heavy, rigid piping used for drain-waste-vent (DWV) systems in many older homes. Cast iron pipe is made by pouring molten iron into molds and is known for its durability and sound-deadening qualities. It is not to be confused with ductile iron pipe, which is used in high-pressure municipal systems and not found in typical residential DWV applications.
Cast iron piping has been largely replaced by ABS and PVC in new construction due to cost, ease of installation, and resistance to corrosion. Older cast iron pipes were joined using molten lead and oakum; modern repairs typically use no-hub couplers secured with stainless steel bands.
Related Terms: Corrosion, DWV, No-Hub Coupler, ABS, PVC, Galvanized Pipe
Catch Basin
A drain structure designed to collect water from a low or wet area, with a pipe exiting from the side to direct the water away. The bottom of the basin typically includes a sump or pit to allow sediment and debris to settle out before water enters the piping system. Catch basins may be located in yards, driveways, garage floors, or basement utility areas, wherever surface runoff or wash water needs to be managed.
Inspector Note: Inspectors may observe catch basins in exterior and interior settings.
Related Terms: Floor Drain, Drainage, Surface Water, Garage, Grading