Alternatives To Solid Wood Exterior
Trim
There are other choices for exterior trim besides solid wood,
but understanding how different materials perform and knowing their
limitations is the key to satisfaction.
by Paul Fisette - © 1997
OK. So we all want to use clear, vertical grain, all heartwood
western red cedar or redwood for our exterior trim. This material
is a time-proven warrior, successfully protecting homes for
centuries. It resists decay, remains stable, holds paint well and
works easily. But recently, the supply of these materials has been
strained and prices have become budget-busters for many
projects.
Perhaps just as popular as cedar and redwood is solid wood trim
made from other locally available species. Solid wood is a familiar
material and many builders will use nothing else. Lumber yards who
sell to pro builders report that 90% of the trim they sell is solid
wood, once you eliminate vinyl from the mix. But high-grade trim
material of any species is getting pricey. Builders complain that
the grades are slipping. That the "good stuff" is getting harder to
find.
The apprenticeship method of learning still found in the
building trades encourages the use of conventional materials. The
adoption of new materials and applications is slow to develop.
However, builders are moving away from solid wood trim. Builders
are discovering options: finger jointed wood (primarily red cedar,
redwood, pine and fir); laminated veneer lumber (LVL); hardboard or
medium density fiberboard (MDF); and fiber-cement products.
There was, until very recently, another promising trim product
available to builders. Louisiana Pacific (L.P.) manufactured and
distributed a paper-overlay oriented strand board (osb) product
called Inner Seal ® Trim and Fascia. Amidst a squall of reported
failures involving Inner Seal ® siding products and a resulting
class-action suit against L.P., the trim and soffit products were
pulled from the market. A company spokesperson in the Conroe, Texas
plant where Inner Seal ® siding products are manufactured, defends
the product as a good idea and a good product, indicating that L.P.
yanked the trim line only because it was loosing money. The
antiquated, continuous-press mill used to make the trim products is
blamed for the loss.
As we move away from the tried-and-true toward new products and
new technologies, we must remember there is no panacea. There is a
price to pay. Some products are difficult to install because they
are unfamiliar. Other products are made of materials that require
fussy installation to provide long, durable service. Others closely
resemble their solid-wood cousins but behave differently. The
products reviewed in this article cover a broad range of
performance and price. They all require a shift in attitude, but
not a drop in performance.
Finger Jointed Wood
Of all exterior trim options, finger jointed material is
most readily accepted by builders. It is welcomed as a less-
expensive alternative to solid wood even in the conservative
Northeast. "The Northeast is one of our hottest markets," says
Keith Kersell, manager of sales and technical services, Pacific
Lumber Company (PALCO), Scotia, CA. Keith sees the heaviest demand
for finger jointed exterior trim in New England, California, the
Gulf States, and the Eastern Seaboard.
Finger jointed wood has a lot going for it. It is a more
efficient use of wood fiber. Short high-grade lengths of wood are
extracted form otherwise low-grade lumber and reconstituted into
long, straight, clear pieces of trim. Exterior weather-resistant
glues like melamine-urea or phenolic resin are used to bond the
short lengths together to endure exposed conditions. And as far as
labor goes, there is no learning curve. It is installed just like
solid wood.
Trim stock is available in virtually all species and profiles.
Most popular is 1- and 5/4- inch trim that is 4" - 12" wide. The
wider widths like 10's and 12's are often created by edge-gluing
several narrower widths together. Edge-gluing is done at the
producing mill's option. When you order finger jointed trim at the
lumber yard, you buy a glued product - period. The mill assembles
the trim boards according to the widths available during the
production run. If they have narrow widths available, then you get
edge-glued trim boards. Sixteen-foot lengths are standard fare, but
finger jointed trim is readily available in lengths up to 24 feet.
Long lengths and 5/4-inch thickness are especially desirable for
corner board applications where unbroken lengths and deep returns
for siding are called for.
Finger jointed material comes in several grades: clear vertical
grain all-heart; clear vertical grain (sapwood present); clear flat
grain all-heart or clear flat grain (with sapwood). The best choice
of course is clear, vertical grain all-heartwood.
Only heartwood is naturally resistant to decay. And vertical
grain material holds paint much better than flat grain material
because it is more stable. It shrinks and swells less across its
face and has less grain-raising than flat-sawn lumber. As wood
moves (shrinks and swells) under a coating of paint, it stresses
the bond between the paint and the wood. Ultimately the film of
paint is sheared from the surface of the wood. Builders often think
that they are going to get vertical-grain performance form
flat-grain material as long as it is clear. This is just not
realistic. It is getting harder and harder to get vertical-grain
material because the size of available trees are getting smaller,
but specify vertical grain whenever you can get it.
Finger jointed trim is not without its problems. It makes many
builders nervous. Steve Ferrari, Project Manger, Kohl Construction
in Hadley, MA is a typical example. Kohl construction is a
progressive-minded company that readily embraces new technology.
Kohl uses all the latest products in their high-end, high-quality
homes. But Ferrari is quick to say, "We are reluctant to use a
finger jointed product outdoors." Builders like Ferrari balk
because of horror stories they hear about finger-jointed trim.
Stories that tell of finger jointed brick molding literally falling
apart after a few years of exposure. And other stories where finger
joints have telegraphed through the finish coating of paint.
While tales of woe sift from the field, finger jointed trim
still holds promise. Most problems lie in the fact that it looks
just like solid wood, but it behaves differently. It is a different
material. Consider that you are gluing two different pieces of wood
together when you form a finger joint. Even if these two pieces of
wood were harvested from the same tree, and exposed to precisely
the same moisture conditions during manufacturing, it is unlikely
that they will have the exact same grain orientation. Therefore, if
exposed to moisture variation in service, each piece will shrink
and swell differently, stressing the joint. You will at least "see"
the joint if the material is not well-protected. Severe exposure to
moisture cycling may eventually cause the joint to fail. This is
the basic undoing of finger jointed trim. It requires special care!
Finger jointed trim can and does work well when it is specified and
handled correctly.
- specify vertical grain material (heartwood of durable species
best)
- specify exterior-exposure adhesive in joints
- factory or field-apply oil-base prime coat on all
surfaces.
- use 2 coats of 100% acrylic latex paint for top coats (do not
use stains)
- maintain protective coating on regular basis
- carefully detail architectural elements to minimize
exposure
Laminated Veneer Lumber (LVL)
The manufacturers of engineered wood have expanded their
vision. You can now buy laminated veneer lumber (LVL) exterior
trim. LVL is made by the parallel lamination of veneers into
thicknesses desired for a given application. And just as the first
applications of structural LVL were inspired by rising costs and
shortages of high-grade lumber; the development of LVL trim is
driven by rising costs and reduced supplies of high-grade
appearance-grade material. South Coast Lumber Company in Brookings,
OR manufactures an LVL trim product called Clear Lam.
South Coast LVL is made of Douglas-fir core-veneers and alder
face-veneers. The layup is glued with a phenolic-based exterior
glue and sprayed with a preservative to protect the product in the
field. The face that is intended to be exposed to the weather is
overlayed with a phenolic-based MDO that is about 20/1000" thick
(MDO or medium density overlay indicates that the overlay sheet is
20 % resin solids by weight). As the 48-inch wide LVL sheets come
out of the press, they are gang-ripped and precision sanded to
widths usable as fascia, soffit and other trim components. Once the
individual pieces of trim have been sized, they are fully coated
with an elastomeric edge coating and primer. All traces of veneer
edge-grain is masked.
Clear Lam is actually a second generation LVL trim product.
Their first product, clear trim , did not have an MDO face. Ron
Rutherford, South Coast Lumber's Sales Manager indicates, "The
reason we have gone to a paper face is because we saw a lot of face
checking in the product we made without the overlay." Field
conditions can be harsh. You can not easily control the amount of
heat and moisture that these products are exposed to. So South
Coast improved its offering. Rutherford reports, "The MDO facing
eliminated the only problem expressed by contractors about our
product."
Clear Lam is stocked by distributors around the country. The
1-inch and 5/4-inch thick material in widths (in 2" increments)
from 4-inches to 12-inches is readily available. Sixteen and twenty
foot lengths are standard. But if you schedule your order with a
3-week lead time, LVL trim can be ordered from the factory in
thicknesses that range from 5/8" to 1 1/4", widths up to 48-inches
and lengths up to 24-feet.
The list of benefits are long: It is easy to cut, nail and
install; it is durable; it paints well; is available in long
lengths and a variety of widths; has no knots or cross-grain; and
is dimensionally stable. So where is the catch you ask? I don't
really have much bad news except that it is a little pricey.
The builders I spoke with like the stuff. Steve Greenwell, owner
of Renaissance Builders in Turners Falls, MA sums up the feelings
of many when he says,"We have used quite a bit of the LVL trim and
we have had great luck. It stays together and paints well."
Greenwell has used it for fascia, corner boards, window surrounds
and has had only 1 bad piece. However, builders disagree with the
dealers contention that stocking only 16-foot lengths is a
waste-saving measure. This decision creates waste. Greenwell
offers, "If dealers think they are saving waste, let them come
visit my shop and I'll show them a bin full of 6-footers." The
question: if you build a cape or ranch with 9'6" corner boards,
what do you do with the other 6'6"? Dealers should stock these
products in at least 2 lengths, maybe 10-footers and
16-footers.
Often, builders combine LVL fascia and rake trim with MDO
plywood soffits. Half-inch thick MDO plywood costs around $35/sheet
and 48"-wide sheets are stock items in all lumber yards. MDO has a
long and successful track record for exterior painted surfaces. It
is regularly used by highway departments for painted road
signs.
Hardboard Trim
There are currently 4 manufacturers of hardboard trim in
the United States: Temple Inland, Georgia Pacific, ABTco, and
Forestex Company. All refer to their trim lines as (and would like
you to start calling it) engineered wood. Each company's fiberboard
is made in roughly the same way. Hardwood chips are heated with
steam and hot water and then passed through 2 rotating discs to
create the fiber that is eventually pressed into board stock. An
interesting thing happens during this process. When the wood fibers
that were sheared apart are hot-pressed into boards, lignin
normally found in wood cells begins to flow. In a sense the wood
fibers are coated by their own lignin. Lignin is a
naturally-occuring "adhesive" that holds wood together. Brown rot
fungus does not attack lignin. And many scientists believe that it
is this fact that causes hardboard to be a little more resistant to
decay than some untreated species like spruce, pine and fir.
There are many similarities among the fiberboard products sold
to builders. Hardboard trim is readily available in all regions of
the country. All hardboard trim products weigh about the same,
around 50 pounds per cubic foot. This is about twice as heavy as
solid redwood. Hardboard trim products are available in 1- and 5/4-
inch thickness, 4" - 12" widths and 16-foot lengths. Manufacturers
offer 7/16-inch thick soffit material too. The trim is made with an
exterior-grade binder and usually comes in smooth and wood-figured
textures. The motivating force for developing these products is
cost and availability of high-grade solid wood.
TrimCraft ®, manufactured by Temple-Inland Forest
Products, Corp., Dibol, TX, was introduced 4 years ago. Product
manager, Gary Martz, claims, "Market acceptance has absolutely
blossomed." TrimCraft ® is not overlayed with an MDO or
any kind of facing. The material is homogeneous throughout its
cross section. It is a reversible product: smooth on one side and
textured to look like cedar on the other side. Temple laminates 2
pieces of hardboard together to create a 1-or 5/4-inch thick trim
product which is sold for fascia, rakes or corner boards.
TrimCraft ® comes factory primed on all surfaces.
ProTrim ® trimboard is manufactured by ABTco, Inc.,
Roaring River, NC. The company changed hands in October of 1992.
Its name changed from Abitibi-Price to ABTco, but the product is
exactly the same. ProTrim ® is similar to Temple Inland's
product is all respects but one: ProTrim ® is faced with a
paper overlay they call their "fusion finish". The overlay is a
newspaper-quality paper that is bonded with the addition of linseed
oil. "The wood fiber and paper become one.", according to Michael
Donaldson, ABTco's manager of product design. Donaldson claims that
ProTrim ® paints better because of this process. And even
the competition agrees. Gib Landis, sales manager for Georgia
Pacific says,"They have perhaps the best surface in the business.
It paints like a piece of glass." But Landis is quick to add that
there is more to performance than paintability. He feels G.P."s
products are best because "They paint nicely, and are unusually
resistant to rot."
PrimeTrim ® , an unfaced hardboard trim product
manufactured by Georgia Pacific, Atlanta, GA, comes primed on its
face and two edges. It is not back-primed. PrimeTrim ® has
been tested and its resistance to decay has been measured by the
Wood Products Laboratory at Mississippi State University. While it
is still a mystery why --- G.P.'s PrimeTrim ® scored
extremely well. It proved to be just slightly less resistant than
cedar lumber siding and slightly more resistant than redwood lumber
siding when tested according to ASTM D-2017. In this test , wood
samples are exposed to rot fungus, put in an incubator and the
weight-loss due to rot is measured. Other hardboard manufacturers
do not make similar claims.
Forestrim ® , another unfaced fiberboard trim product,
is the new kid on the block. Forestex in Forest Grove, OR
introduced Forestrim ® just 1 year ago. At this time it
comes only in a 5/8-inch thickness, but the company is
experimenting with a 1-inch thick product and expects to have it
on-line soon. Trim boards that are 3 1/2-inches wide are readily
available and other widths can be special ordered.
Each of the manufacturers I talked with expressed concern over
the reputation hardboard siding seems to have developed among
builders. Many builders I know (myself included) have had problems
using hardboard siding. Thickness-swell is a problem. Wood fibers
are compressed in the hot-press when the boards are made. Some of
this compression stress is relieved over time. This causes the
swelling that is observed around nail heads and at the ends of some
boards. Hardboard is more likely to absorb moisture and swell where
unprotected fibers are exposed to weather. The forces associated
with thickness swell are so great that they cause paint coatings to
fail along the edges of boards. Water enters cracks and unprotected
penetrations (like over-driven nails) in the paint surface
accelerating the degrade process. Even if the claims of
rot-resistance are accurate, softening, swelling and delamination
of fiberboard is an undeniable concern.
Buckling can be a problem too. As we go from solid wood to
hardboard during the manufacturing process, we tear down the grain
structure of wood, randomize the fiber direction and put it back
together as a homogeneous material. The low longitudinal expansion
of solid wood is averaged out with the higher tangential and radial
potentials. As a result, hardboard shrinks and swells more along
its length than solid wood. But manufacturers blame improper
application, detailing and maintenance for swelling and buckling
problems.
You should flush-nail this product with corrosion-resistant
nails. Over-driven nails must be sealed with a paintable caulk.
Butt joints must have a 1/8-inch gap that is filled with a flexible
caulk. Edges like those where corner boards are joined should not
be mitered. All surfaces (face, nail heads and cut edges) should be
sealed with 2 coats of acrylic latex paint. Do not install
hardboard in direct contact with concrete. Never nail from both
ends of a board toward the middle. And hardboard should be reprimed
prior to finishing if it is left unpainted for longer than 60 days.
If you follow these rules, manufacturers claim you won't have
swelling or buckling problems. The problem then becomes a
maintenance issue.
Temple Inland's Martz says that their TrimCraft product can go 5
to 10 years between painting as long as the base coat of paint is
applied correctly. By all accounts, to expect this kind of paint
performance on any material is truly optimistic. But good flashing,
smart detailing and frequent painting should keep customers happy
with hardboard trim products.
Installing hardboard trim takes some getting used to. Steve
Ferrari says, "I love it, but my carpenters hate it." Steve, like
many builders, has had very good luck using these products. He is
fussy with the details. And the houses I visited looked perfect
after 4 years of service. However, his carpenters find it difficult
to nail. Getting the right setting with nail guns is tricky. And
they have patched and sanded quite a few nail heads to make their
jobs top-shelf. Overall, it takes a little more to time to install
than conventional wood trim. But for his money, Ferrari thinks it
is a good deal.
Fiber-Cement
Fiber-cement trim has a unique appeal: once you install
it, it's there forever. And as one builder said, "It is not what it
does on the wall, it is what it doesn't do." Fiber-cement composite
is a mixture of wood-fiber reinforcement (under 10%), Portland
cement and sand. It is durable, dimensionally stable, fire
resistant, and immune to the effects of insects, water, and
sunlight.
There are two players in the autoclaved fiber-cement market.
James Hardie Building Products, Inc., Fontana, CA and Eternit,
Inc., Blandon, PA. James Hardi has been manufacturing fiber-cement
for over 100 years in Australia. They offer a full compliment of
fiber-cement building products including roofing, siding, trim and
underlayment. While Eternit and Hardi manufacture very similar
composite trim materials, it is Hardi that is wooing the
light-frame construction market. James Hardi manufactures
HardiTrim ® , a 7/16-inch thick trim product that is
manufactured in 4-, 6-, 8-, and 12-inch widths. It is sold in
12-foot lengths. They also manufacture 1/4-inch thick
HardiSoffit ® in 16-, 24-, 36- and 48- inch widths and 8-,
9- and 10-foot lengths. Eternet, on the other hand, makes several
products, but all are sold in 4'x8' (or larger) panel format, not
user-friendly!
HardiTrim ® is a new product and all sizes are not yet
available in all markets. Furman Lumber's Houston branch is Hardi's
largest distributor and offers all sizes to the Southwestern
market. The product should be rolled out in Northern markets within
a year. With a 50-year transferable warranty and at 60% the cost of
solid wood it is expected to become a popular offering for
Furman.
The first thing builders say when told about a fiber-cement
product is, I don't want to have to drill every nail hole. "You
won't have to pre-drill", says Wes Webb, General Manager for
Furman's Houston branch but, "There is a little bit of learning to
do with this product."
A couple of Webb's major builders have switched to HardiTrimª
and while they like the performance that is promised, they find it
more difficult to work with. They use regular galvanized nails to
fasten it and recommend using a 2"x4" sub-fascia to provide
straight, solid nailing. Fiber-cement is dense(80 psf) and hard.
Straight and miter cuts are made using a circular saw equipped with
a carbide-tip blade. The blade is usually thrown away at the end of
the job. A diamond tip blade lasts much longer, but is slower and
its cuts are not as clean. Because the trim is only 7/16-inch thick
corner boards must be built out with 1/2-thick wood backing. All
fiber-cement boards should be field trimmed because factory ends
are not reliable. Fiber-cement does not have nail-holding power of
its own, so solid nail-backing must be provided behind all
butt-joint and miter connections.
Paint lasts a very long time on fiber-cement. Since the material
is so moisture resistant and stable, stress does not build under
the coating as it does with wood products. In fact, Lee Brunner,
N.E. Sales manager for James Hardi reports that PPG and Olympic
offer a 15-year warranty for their factory-applied finish on Hardi
products. Some fiber-cement products need an alkali resistant
paint, but Hardi recommends a regular acrylic-latex.
Working with fiber-cement is different than working with wood.
It is not only more difficult to nail and cut, it is a dusty
material to machine. Health concerns laid out in the Fiber-Cement
Material Safety Data Sheet should be recognized and respected.
These products contain silica that is bonded securely in place in
its manufactured form. But dust masks should be worn while cutting
or drilling. Breathing silica dust can cause silicosis, a
non-cancerous lung disease.
Last Word
Working with new materials requires patience and an open
mind. Everything doesn't work as easily as wood --- to a large
extent because we are so familiar with wood. We were trained to use
wood and our tool boxes are filled with tools made to work wood.
Builders who have used pine trim for years are satisfied with its
performance, yet pine is not a naturally durable wood. It rots if
it is not protected by careful detailing and a good coating of
paint. Pine has cross-grain and knots. It shrinks, swells and
degrades when exposed to rain and sunlight. I love working with
wood and it is always my immediate first choice. But other
materials can work as well if they are treated with the
understanding that will make them work.
Cost Comparisons
| grade/product |
species |
size |
price/lin.ft. |
| A & better |
western red cedar |
1" x 6" |
1.75 |
| select clear |
eastern white pine |
1" x 6" |
1.25 |
| #2 common |
eastern white pine |
1" x 6" |
0.55 |
| hardboard |
assorted hardwood |
1" x 6" |
0.75 |
| LVL |
Douglas-fir |
1" x 6" |
1.35 |
| fiber-cement |
N/A |
7/16" x 6" |
0.45 |
| finger jointed |
western red cedar |
1" x 6" |
1.15 |
Contacts
Hardboard Products
American Hardboard Assoc., 520 N. Hicks Rd., Palatine, IL 60067
312-934-8800
ABTco Building Products Corp., P.O.Box 98, Hwy. 268, Roaring
River, NC 28669 800-334-3551
Forestex, P.O.Box 68, Forest Grove, OR 97116 503-357-2131
Georgia Pacific, P.O.Box 105605, Atlanta, GA 30348 404-521-4000
or 800-447-2882
Snavely Forest Products, P.O.Box 310, 53 Bannard St, Freehold,
NJ 07728 908-462-2323 or 800-233-0118 (distributes LVL Clear Lam
and ABTco)
Temple-Inland Forest Products, Corp., P.O.Drawer N, Diboll, TX
75941 409-829-5511 or 800-231-6060
LVL Trim
Snavely Forest Products (see above)
South Coast Lumber Company, 815 Railroad Ave., P.O.Box 670,
Brookings, OR 97415 503-469-2127
Fiber-Cement
Eternit, Excelsior Industrial Park, P.O.Box 679, Blandon, PA
19510-0679 610-926-010
Furman Lumber, Inc., P.O.Box 130, Nutting Lake, MA 01865
800-843-9663
------ Houston Branch 800-392-3942
James Hardie Building Products, Inc., 10901 Elm Avenue, Fontana,
CA 92337 800-942-7343
Fingerjointed Wood
Pacific Lumber Company (PALCO), Main St., P.O.Box 37, Scotia, CA
95565 707-764-2222
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