| Habitat | The place where animal or plant species live. |
| Half-Round Slicing: | Half-Round Slicing: Produces a cathedral-like grain veneer with more rounded tops. A variation of rotary cutting that shows modified characteristics of both rotary and plain sliced vendors. |
| Hardboard | A generic term for a panel manufactured primarily from interfelte lignocellulosic fibers (usually wood), consolidated under heat and pressure in a hot press to a density of 496 kg/m3 (31 lb/ft3) or greater and to which other materials may have been added during manufacture to improve certain properties. |
| Hardener | A substance or mixture of substances that is part of an adhesive and is used to promote curing by taking part in the reaction. |
| Hardness | A property of wood that enables it to resist indentation. |
| Hardwoods | Generally one of the botanical groups of trees that have vessels or pores and broad leaves, in contrast to the conifers or softwoods. The term has no reference to the actual hardness of the wood. |
| HCFC | Hydrochlorfluorocarbons or hydrogenated chlorofluorocarbons. Because they are less destructive to ozone, they are a substitute for CFCs (1/10th the environmental damage of CFC) although less efficient as refrigerants and sometimes quite toxic. |
| Healthy Housing | CMHC's sustainable housing program defined as the "Integration of healthy building materials and innovative housing technology that protects the health of the occupants while reducing environmental impact". |
| Heart Rot | Any rot characteristically confined to the heartwood. It generally originates in the living tree. |
| Heartwood | The wood extending from the pith to the sapwood, the cells of which no longer participate in the life processes of the tree. Heartwood may contain phenolic compounds, gums, resins, and other materials that usually make it darker and more decay resistant than sapwood. |
| Heat Island Effect | Occurs as a result of solar energy retention on dark absorbent constructed surfaces causing artificial rise in local temperatures. Principle surfaces that contribute to the heat island include streets, sidewalks, parking lots and buildings. |
| Heat Recovery Ventilator (HRV) | Also known as an Air to Air Heat Exchanger, an HRV maintains high indoor air quality without excessive additional energy costs. It consists of two separate air handling systems - one collects and exhausts stale indoor air, and the other draws in fresh outdoor air and distributes it throughout the home. |
| Heating, Ventilating and Air Conditionin | Heating, ventilating and air conditioning. The mechanical systems that heat, cool, ventilate, filter, humidify or treat air in buildings. |
| Heavy Timber Construction | A type of combustible construction in which a degree of fire safety is attained by placing limitations on the sizes of wood structural members, and on thickness, and composition of wood floors, and roofs, and by the avoidance of concealed spaces under floors and roofs. |
| Hem-Fir | A commercial designation for western hemlock and Amabilis fir, which are nearly identical in appearance and physical properties so they are harvested, processed and marketed together. |
| Hemicellulose | A celluloselike material (in wood) that is easily decomposable as by dilute acid, yielding several different simple sugars. |
| Hertz | A unit of frequency equal to one cycle per second. |
| Hollow-Core Construction | A panel construction with faces of plywood, hardboard, or similar material bonded to a framed-core assembly of wood lattice, paperboard rings, or the like, which support the facing at spaced intervals. |
| Honeycomb Core | A sandwich core material constructed of thin sheet materials or ribbons formed to honeycomb-like configurations. |
| Honeycombing | Checks, often not visible at the surface, that occur in the interior of a piece of wood, usually along the wood rays. |
| Horizontally Laminated Timbers | Laminated timbers designed to resist bending loads applied perpendicular to the wide faces of the laminations. |
| Hot Setting Adhesive | An adhesive that requires a temperature at or above 100¡C (212¡F) to set it. |
| Hot-Melt Adhesive | An adhesive that is applied in a molten state and forms a bond on cooling to a solid state. |
| HPL | The synergies that exist between composite panel substrates and the many decorative surfacing options available provide limitless design and application opportunities. Please use the information on this website and the advice of your supplier to help you specify the appropriate substrate and decorative surface to best meet the needs of your application. |
| HPVA | HPVA's mission is "to promote and support the long-term growth and prosperity of our industry, our members, and the natural resources upon which we depend," but we also develop industry statistics and keep our members up-to-date on the latest developments and technology affecting the industry. |
| HUD stands for Housing and Urban Development | HUD stands for Housing and Urban Development. Panel products must meet specific standards set forth by HUD. For more information about the HUD requirements, visit CPA www.pbmdf.com or the American National Standards Institute at www.ansi.org. |
| Hydrogen Bond | An intermolecular attraction force that results when the hydrogen of one molecule and a pair of unshared electrons on an electronegative atom of another molecule are attracted to one another. |
| Hydrophilic | Having a strong tendency to bind or absorb water. |
| Hydrophobic | Having a strong tendency to repel water. |