Underlay
Encyclopedia
Underlay or underlayment generally refers to a thin layer of cushioning made of materials such as sponge rubber
, foam
, felt, or crumb rubber
; this material is laid beneath carpet
ing to provide comfort underfoot, to reduce wear on the carpet, and to provide insulation against sound
, moisture
, and heat
. In general, it is a layer which is underneath another layer, so underlay is thus also used to describe many different surface-covering products.
In vinyl flooring or "linoleum
", the underlay is the thin layer of plywood that is fastened over the structural subfloor to create a uniform, smooth platform for the sheet vinyl. For laminated wood flooring, the underlay provides a “vapor barrier” to prevent moisture from coming through the floor of the home and then migrating into the flooring; the underlayment may also have noise-dampening properties.
A self-leveling underlay is a cement-like product that can be pumped in liquid form onto the floor in order to create a level floor.
Underlay is also the term for the material under roofing tiles; this roofing membrane is often made of rubber and is used to seal the roof and prevent leakage.
Bedding underlay (or mattress overlay) is a thick, extra layer of padding between the bed mattress
and bedding
. Underlays are designed to increase comfort and support, while extending the life of the mattress (or mattress protector
). Common underlay materials include: Wool
, foam, and latex
.http://www.spotlight.com.au/departments/bedroom/bedding-faq/http://www.clarkrubber.com.au/foam-and-latex-mattress-proctectors-mattress-overlays-clark-rubber.htmlhttp://www.homeimprovementpages.com.au/article/bedding_underlay
In Music, Underlay refers to text intended for vocalization – positioned either directly or indirectly under notes on a musical staff.
Carpet underlays are typically 6-10mm. They primarily provide foot comfort, but they also reduce carpet wear and provide sound and thermal insulation.
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
, foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
, felt, or crumb rubber
Crumb rubber
Crumb rubber is a term usually applied to recycled rubber from automotive and truck scrap tires. During the recycling process steel and fluff is removed leaving tire rubber with a granular consistency. Continued processing with a granulator and/or cracker mill, possibly with the aid of cryogenics...
; this material is laid beneath carpet
Carpet
A carpet is a textile floor covering consisting of an upper layer of "pile" attached to a backing. The pile is generally either made from wool or a manmade fibre such as polypropylene,nylon or polyester and usually consists of twisted tufts which are often heat-treated to maintain their...
ing to provide comfort underfoot, to reduce wear on the carpet, and to provide insulation against sound
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
, moisture
Moisture
Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...
, and heat
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
. In general, it is a layer which is underneath another layer, so underlay is thus also used to describe many different surface-covering products.
In vinyl flooring or "linoleum
Linoleum
Linoleum is a floor covering made from renewable materials such as solidified linseed oil , pine rosin, ground cork dust, wood flour, and mineral fillers such as calcium carbonate, most commonly on a burlap or canvas backing; pigments are often added to the materials.The finest linoleum floors,...
", the underlay is the thin layer of plywood that is fastened over the structural subfloor to create a uniform, smooth platform for the sheet vinyl. For laminated wood flooring, the underlay provides a “vapor barrier” to prevent moisture from coming through the floor of the home and then migrating into the flooring; the underlayment may also have noise-dampening properties.
A self-leveling underlay is a cement-like product that can be pumped in liquid form onto the floor in order to create a level floor.
Underlay is also the term for the material under roofing tiles; this roofing membrane is often made of rubber and is used to seal the roof and prevent leakage.
Bedding underlay (or mattress overlay) is a thick, extra layer of padding between the bed mattress
Mattress
A mattress is a manufactured product to sleep or lie on, consisting of resilient materials and covered with an outer fabric or ticking. In the developed world it is typically part of a bed set and is placed upon a foundation....
and bedding
Bedding
Bedding refers to the materials laid above the mattress of a bed for hygiene, warmth, to protect the mattress, and for decorative effect. Bedding is the removable and washable portion of a human sleeping environment. It is more easily and economically replaced than the bed itself...
. Underlays are designed to increase comfort and support, while extending the life of the mattress (or mattress protector
Mattress protector
A mattress protector, mattress topper, mattress pad, or underpad is an item of removable bedding that sits on top of or encases a mattress to provide protection to the mattress...
). Common underlay materials include: Wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
, foam, and latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
.http://www.spotlight.com.au/departments/bedroom/bedding-faq/http://www.clarkrubber.com.au/foam-and-latex-mattress-proctectors-mattress-overlays-clark-rubber.htmlhttp://www.homeimprovementpages.com.au/article/bedding_underlay
In Music, Underlay refers to text intended for vocalization – positioned either directly or indirectly under notes on a musical staff.
Carpet
Popular carpet underlays are- foam rubber
- crumb rubber
- felt
Carpet underlays are typically 6-10mm. They primarily provide foot comfort, but they also reduce carpet wear and provide sound and thermal insulation.