Wood or timber "decking" can be used in a number
of ways: as part of garden landscaping, to extend living areas of houses, and
as an alternative to stone based features such as patios. Decks are made from
treated lumber, composite lumber, composite material, Aluminum, Western red
cedar, teak, mahogany, ipê and other hardwoods and recycled planks made from
high-density polyethylene (HDPE), polystyrene (PS) and PET plastic as well as
mixed plastics and wood fiber (often called "composite" lumber).
Artificial decking products are often called "wood-plastic
composites". These days, WPC's have more widely known by different brands
like Trex, Azek, Ecornboard etc.
Historically, the softwoods used for decking were logged
from old growth forests. These include Atlantic white cedar, redwood and
Western red cedar (redcedar). Atlantic City built the first coastal boardwalk
in the United States, originally constructed of Atlantic white cedar. However,
it was not long before the commercial logging of this tree and clearing of
cedar swamps in New Jersey caused a decline in the availability of decking.
Atlantic City and New York City both switched to Western red cedar. By the
1960s, Western red cedar from the US was declining due to over-logging. More
expensive Western red cedar was available from western Canada (British
Columbia) but by then, pressure treated pine had become available.
But even with chemical treatments (such as chromated copper
arsenate or CCA), pine decking is not as durable as cedars in an outdoor
environment. Thus, many municipalities and homeowners are turning to hardwoods.
Decks are often built from pressure treated wood. Pressure treated wood is long
lasting and holds up to wet and icey weather conditions. Pressure treated wood
however is treated with chemicals which have been known to be toxic.[1] Slivers
received from pressure treated wood most generally become infected. Pressure
treated saw dust also contains toxins such as strychnine, also often used as
rat poison. These toxins, when inhaled, can require hospitalization for both
acute and chronic exposures.
Generally, hardwoods used for decking come from tropical
forests. Much of the logging taking place to produce these woods, especially
teak, mahogany and ipê, is occurring illegally, as outlined in numerous reports
by environmental organizations such as Greenpeace, Friends of the Earth and
Rainforest Relief.[2][3][4] US tropical wood imports are rising, partly due to
the demand for decking.
Due to environmental concerns, composite decking (a mixture
of two materials, typically wood pulp and recycled material such as plastic
bottles or plastic bags) have appeared on the market. Proponents of composite
decking have touted this as a much needed development as this helps to curb
logging of trees for new decks. However composite decking has been found to
contain harmful chemicals, cannot be refurbished, and despite claims from
decking companies, the composite deck still attracts molding.[5]
Residential decks may contain spaces for BBQing, dining and
seating. BBQ areas ideally should be situated near the patio door while out of
the way from general foot traffic. Dining spaces will include patio tables, for
a typical 6 person outdoor patio table building an area of 12' x 16' is ideal.
If deck space is available, homeowners may choose to include a seating area for
outdoor couches and benches.
Construction[edit]
The deck of a house is generally a wooden platform built
above the ground and connected to the main building. It is generally enclosed
by a railing for safety. Access may be from the house through doors and from
the ground via a stairway. Residential decks can be constructed over steep
areas or rough ground that is otherwise unusable. Decks can also be covered by
a canopy or pergola to control sunlight. Deck designs can be found in numerous
books, do-it-yourself magazines and web sites, and from the USDA.[6]
Larger buildings may also have decks on the upper floors of
the building which may be open to the public as observation decks or a Skyrise
greenery.
A deck is also the surface used to construct a boardwalk
over sand on barrier islands.
Laying deck or throwing deck refers to the act of placing
and bolting down cold-formed steel beneath roofing and concrete floors. This is
usually done by an ironworker, sometimes in conjunction with a cement mason or
carpenter. It regarded as one of the most physically demanding jobs in the iron
working industry.
In the UK the various ban on smoking in public buildings was
expected lead to an increase in the use of timber decking for outdoor spaces
where smokers can gather.[7]
No comments:
Post a Comment