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Is it true
that Oak is better suited for the manufacture of trailer
floors than Maple?
False!
The answer to this question lies essentially
in the expertise of the manufacturer. Wood is only one of
the components used in the production of trailer floors.
The manufacturing process, the gluing process, quality control,
etc., are all important elements to consider. Strength,
durability and a superior quality of flooring are created
by perfect control of all the stages of production and are
not solely dependent on the physical and mechanical characteristics
of the wood.
Is Maple
less durable than Oak?
No! On
the contrary, Hard Maple possesses characteristics superior
to Oak. Hard Maple resists higher loads, is more rigid,
and has a stronger bond between the fibers than Oak. As
proof, consider that Maple trailer floors have been manufactured
since 1982.
|
Hard Maple
|
Northen
Red Oak
|
White Oak
|
Modulus
of rupture
(Strength) (kPa) |
109,000
|
99,000
|
105,000
|
| Modulus
of elasticity (Stiffness)
(Mpa) |
12,600
|
12,500
|
12,300
|
| Work
to Maximum load (kJ/m3) |
114
|
100
|
102
|
| Shear
parallel to grain (kPa) |
16,100
|
12,300
|
13,800
|
| Side
hardness (N) |
6,400
|
5,700
|
6,000
|
Some people say that it is more
difficult to nail into Maple than Oak; when one nails into
Maple, the wood supposedly has a tendency to split. Is there
any truth in this?
Any experienced
carpenter will tell you: to nail effectively into hardwood
and to avoid splitting, flatten the point of the nail before
driving it into the wood. A normal nail (pointed) could
split hardwood. Using a nail with a flat point prevents
splitting. By applying this simple trick, it becomes easy
to nail into hardwood.
Within the industry, some people
are spreading a rumor that Maple is more difficult to glue
than Oak. Is this true?
Absolutely not!
The study Wood handbook--Wood as
an engineering material (chapter 9, page
8) by U.S. Department of Agriculture, Forest Service,
Forest Products Laboratory classifies Hard Maple, Red
Oak and White Oak in the same category based on their ease
of bonding. Under perfectly controlled conditions using
high quality glue, Red Oak, White Oak and Hard Maple are
rated exactly the same. Based on this scientific study,
we can say that Maple is not more difficult to glue than
Oak.
Actually, everything lies in the knowledge and technique
of gluing the laths, to such an extent that, with a well-tested
gluing technique, a Hard Maple trailer floor will be more
durable than one in Oak.
Is it true that trailer floors in
Maple decay more quickly than those in Oak?
Wood decay is another
false notion that has spread through the industry. In order
to develop decay, it is necessary to have a proliferation
of fungi. According to the technical report Decay
of Wood (1) and the American study The
Nature of Wood and Wood Products (2), the moisture
content of the wood must lie between 30% and 50% (depending
on the species of the fungus and of the wood) for destructive
fungus to develop. For example, air-dried wood could contain
up to 18% moisture. Under these conditions, we can consider
the wood to be immune to fungus attack and consequently,
immune to decay.
Under normal use, the moisture content of a trailer floor
will rarely exceed 20%. Consequently, the probability of
reaching the minimum threshold of 30% moisture content necessary
for the development of destructive fungus becomes practically
zero.
However, if the trailer floor exceeds 30% moisture content
under extreme prolonged conditions, fungi could develop.
But the return to normal conditions (less than 20% moisture
content) would simply render the fungi harmless.
If you still think decay might be a problem, the studies
Wood handbook--Wood as an engineering
material (3) (chapter 3, page 18) and Hardwood
of North America (4) confirm that Maple is as resistant
to decay as Red Oak, which has been used for many years
in trailer floor manufacturing.
Sources:
1 Decay
of Wood. NRC's Institute for Research in Construction
(Canada), 1972
2 The Nature of Wood and Wood Products.
Forest Products Management Development Institute, University
of Minnesota.
3 Wood handbook--Wood as
an engineering material. Gen. Tech. Rep. FPL-GTR-113.
Madison, WI: U.S. Department of Agriculture, Forest Service,
Forest Products Laboratory.463 p.
4 Hardwood of North America
- Gen. Tech. Rep. FPL-GTR-83. Madison, WI: U.S. Department
of Agriculture, Forest Service, Forest Products Laboratory.
136 p.
In the industry, there is a belief
that Maple has a stronger tendency towards shrinkage than
Oak. Is this true?
As explained in the technical report
Wood
handbook--Wood as an engineering material
(chapter 3, page 9) of the U.S. Department of Agriculture,
Forest Service, Forest Products Laboratory, the percentage
of shrinkage in Maple species is comparable to that of White
Oak in identical conditions of humidity. The belief that
Hard Maple performs poorly in comparison to Oak is totally
unjustifiable. Oak demonstrates no marked advantage in terms
of shrinkage in comparison to Hard Maple.
Shrinkage (%) from green to ovendry moisture
content
|
Species
|
Radial
|
Tangential
|
Volumetric
|
|
Maple (Hard)
|
4.8
|
9.9
|
14.7
|
|
Oak (Northern Red)
|
4.0
|
8.6
|
13.7
|
|
Oak (White)
|
5.6
|
10.5
|
16.3
|
Source: Wood handbook--Wood
as an engineering material. Gen. Tech. Rep. FPL-GTR-113.
Madison, WI: U.S. Department of Agriculture, Forest Service,
Forest Products Laboratory.
Is Hard Maple lighter
than White Oak? If so, does that mean that it will be less
strong?
Hard Maple, because it is less dense,
is naturally lighter than White Oak. In concrete terms,
a Hard Maple trailer floor weighs up to 100 pounds less
than a White Oak floor. This creates added savings in transportation
costs proportional to the size of your fleet.
However, less density does not equal less strength. The
physical properties of Hard Maple are such that it is stronger
and has greater rigidity than White Oak. In conclusion,
Hard Maple offers the best of both worlds: light weight
and strength.
As a manufacturer,
can a low inventory level of trailer floors possibly be
interpreted as an inability to deliver an order on time?
Absolutely not. This is a question
of intelligent planning and the availability of manpower;
commonly termed “just in time.”
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