Infiltration 
Air from the environment that penetrates crevices in a building. Penetration of water into the earth or through a structure. 

Infiltration Test 
Testing a buried pipeline for leakage by sealing the empty line and checking to see if any water leaks into the system from another source. 

Infinite 
1. Lacking limits or bounds. 
2. Very great, vast, immense. 

Inflatable Plug 
Elastomer plug, which can be inflated and is often used to seal off a portion of a pipeline that needs to be pressure tested. 

Inflate 
To blow full or expand out as with air or gas. 

Inflation 
Increasing price levels. A loss in the purchasing power of money. When a dollar today is worth more than that dollar tomorrow. 

Inflation Equity 
Increase in the value of property brought on by inflation. 

Information Reporting 
Income reporting to the Internal Revenue Service using Form 1099 stating income earned.

Information Stake 
Stake used to give grades at different distances from the hub near which is located when surveying. 

Infrared 
Invisible rays just under the red end of the visible spectrum. Waves are longer than those of the spectrum colors but shorter than radio waves; they have a penetrating heating effect and, consequently, are used in cooking, photograph, etc. 

Infrared Brazing (IRB) 
Use of infrared radiation to heat the material being brazed. 

Infrared Soldering (IRS) 
Use of infrared radiation to heat the material being soldered. 

Infrared Testing 
Testing can be done either by inducing heat energy into an object, which is active, or by using the natural infrared energy of an object, which is passive. Testing is used to test insulation materials and installations, with variations of 0.01 degrees Fahrenheit able to be detected, as well as variations within the material being examined. 

Infrasonic 
A frequency of sound below the range audible to humans. 

Infrastructure 
The basic public works in a city including roads, parks, bridges, schools, utilities and communication systems in a community. 

Infusorial Earth 
Chalk-like gray or white silicon, composed of fossilized remains of marine life, which is used for thermal insulation for steam piping, paint extenders, scouring powders, filters, etc. Also called Tripoli or Diatomaceous Earth or Diatomaceous Silica. 

Ingress and Egress 
Access from a land parcel to a public road or other means of exit. Right to exit and enter through land owned by another. 

Inharmonious 
Inappropriate and possibly harmful use of land.

Inheritance 
Personal property or real estate that is passed on to the heirs of a deceased. 

Inheritance Tax 
State tax based on the value of property received through inheritance. 

Inhibitor 
Any substance that slows or prevents a chemical or organic reaction. Concrete set up is retarded by addition, to the cement mix, during hot weather, of starches or fatty acids. 

Initial Interest Rate 
Original interest rate on an adjustable mortgage. Sometimes the initial "teaser" rate is below the current market rate. 

Initial Payment 
The down payment on the price of a piece of real estate. 

Initial Rate Cap 
Specific limit of some adjustable rate loans (ARMs) defining the maximum amount the interest rate may increase at the expiration of the original interest rate. 

Initial Rate Duration 
A time period, lasting either months or years, before the initial interest rate expires and an increase takes place. 

Initial Rate of Absorption 
In accordance with ASTM C67, weight of the water that can be absorbed in one minute by a partially water immersed brick. 

Initial Set 
The first hardening of mortar. 

Injunction 
A court order issued to a defendant in an action either prohibiting or commanding the performance of a defined act. Violation of an injunction could lead to a contempt of court citation. 

Inlay 
To set pieces of wood, metal, etc. into a surface, making a design that is normally level with the surface of the base material. Tabletops are often created with different types of wood. 

Inlet 
1. An entrance, opening or passage as to a culvert. 
2. A narrow strip of water extending into a body of land from a river, lake, ocean, small bay or creek. 
3. Opening for the intake of fluid. 

In-line Pump 
Small pump, which is pumping fluid through a line on which it is supported and mounted.