trim boards should be stored on a level,
flat surface. If stored on an uneven surface for an
extended period, some waviness in the boards could
occur. This may cause them to be unsuitable for certain
trim boards have one of the hardest and most
reasonable handling at the lumber yard and on the job site.
Care should be taken to avoid unnecessary damage.
trim boards are shipped in pallet units
enclosed in protective shrouds. After clipping unit
bands, continue to use the protective shrouds.
4. Additionally, KOMA
offers boards in individually shrink
not remove shrink wrap until ready to install. This will
help keep the material free of dirt and debris.
1. All exterior building materials require some degree of
maintenance and cleaning. Most stains are caused
naturally or environmentally and do not constitute a
manufacturing defect. Just like wood, KOMA
droppings, or stains resulting from normal use and
2. Below are products that are effective for general
cleaning and will not harm KOMA
appropriate selection. Always follow the manufacturer’s
instructions for use and test in an inconspicuous area.
- Super Clean™
- Clorox Outdoor Bleach Cleaner™
- Or equal
3. Denatured alcohol or mineral spirits can be used to
remove smudges left from handling during installation.
4. Do not use harsh (aggressive to PVC) solvents such as
acetone, toluene, MEK, etc.
5. For exceptionally stubborn or ground-in dirt a cleaning
solution can be prepared by mixing: 1/3 cup powdered
detergent (such as Fab™ or Tide™) and 2/3 cup
powdered household cleaner (Spic™ & Span™,
Soilax™) in one gallon of water. Apply the cleaning
solution with a stiff-bristled brush (nylon, or natural
fiber) and rinse thoroughly.
6. If mildew is present, use a solution of 30% vinegar and
70% water or a mixture of: 1/3 cup of non-ammoniat-
ed powdered detergent, 2/3 cup tri-sodium phosphate
(TSP, sold in paint stores) and one quart of chlorine
bleach in one gallon of water. Apply the solution with
a stiff-bristled brush and rinse thoroughly.
WARNING: NEVER MIX CHLORINE BLEACH WITH
AMMONIATED CLEANERS. A DANGEROUS GAS
trim boards can also be cleaned by sanding.
See the sanding section for recommendations.
trim boards are non-structural decorative trim.
2. Nail guns and fasteners intended for typical wood trim
installations will work with KOMA
the back side of installed trim.
4. Fasteners should penetrate solid framing substrate
at least 1 1/4” and be spaced no farther apart than
16” on center.
Figure 1 on the following page demonstrates proper
pressure, nail gun depth stop) to countersink the head
of the nail 1/16” to 1/8” below the surface. Test on
pieces of scrap before applying finished product.
6. Use non-corrosive fasteners for lasting results. We
suggest stainless steel or a coated fastener that has
passed ASTM B117 test criteria.
7. When hand nailing, avoid striking the board surface
with excessive force.
8. Where possible, glue KOMA
trim boards to the
use with PVC (see Figure 4). Always read the adhesive
label or check with the manufacturer to confirm that
the adhesive is appropriate for use with PVC.
thermal movement. Adhesive should never be used as
a subsitute for proper nailing schedule.
10. Use accepted trim installation nailing schedules based
upon standard residential light frame construction
layout (16 o.c.). Wider boards will require additional
fasteners at each fastening location.
Figure 2 specifies the number of fasteners required at each
11. Provide adequate blocking at all joints. Use butt joints
to join boards in long runs, e.g., fascia, frieze, rake, or
12. Pre-drilling KOMA
trim boards may be necessary
in low temperatures.
13. When applying more than
three fasteners to a board
in the same stud/blocking
location, slightly stagger
the line of the fasteners.
should not be used as
load bearing elements or
assemblies for structural
applications. Never install
to a span greater than 16”.
2. Fasten KOMA
edge & center bead board every 12”
edge & center bead
installed surface area.
3. When spanning greater than 16”, install blocking and
bracing. In the case of spanning/covering rafter tails
with spacing greater than 16” o.c., install a continuous
sub-fascia onto which the KOMA
trim boards and
etc.) will be fastened.
trim boards are polymer based and
will expand and contract with changes in temperature.
trim boards will minimize
ture. Where possible, adhere KOMA
trim boards to the
adhesive on the back of KOMA
trim boards (see
fasteners (“fastening schedule” outlined in fastening).
MINIMUM 15 ga.
3. Apply construction adhesive in a stop start diagonal
line pattern with a bead size of 1/4” – 3/8” diameter
on to the substrate area the KOMA
trim boards will
4. Properly bonding joints between pieces of KOMA
trim boards with a suitable structural adhesive or
discourage separation and unsightly gaps.
5. Positioning expansion joints along runs >36’ can
accommodate movement that occurs due to changes
Figure 5 is a cross-section of an expansion/control joint.
If you have any questions pertaining to these
support at KOMA Building Products (800.330.2239).
KOMA® Building Products
Bonding KOMA to KOMA, excellent for filling fastener holes.
Color matched to KOMA with UV stabilizer. Standard
formulation cures in 15-20 minutes; 5 Minute fast-cure
formula available. Delivered through a mixing nozzle from
a plural component gun.
Plural component, fast curing, high
strength, more flexible than epoxies
PL Polyurethane Premium
Attaching trim to substructure and sheathing.
Pl formulation is polyurethane enhanced for superior
elongation and long-term flexibility. Applied from cartridge
using standard caulking gun.
Flexibility, impact resistance, durability
Solvent/Welding Cement White Hot
KOMA Building Products
(Huntsville, AL) 800.330.2239
Welding KOMA to KOMA; dries opaque off-white. Applied
by brush. Available in numerous size cans (smallest with
applicator brush). Water clean-up.
Medium body, clear, one-step self
priming, cleans up with water
Hot White Vinyl
T. Christy Enterprises, Inc.
Welding KOMA to KOMA, UV stabilized, white, excellent gap
filling and for making repairs.
Single component comprised of resins
Notes: The bonding agents listed above have produced excellent results for each category of application. Always test prior to use to determine
suitability and read and follow adhesive manufacturers’ instructions. We encourage other suppliers to provide test data showing equivalent or
superior performance and we will include them in next printing, other technical bulletins, and training/educational materials.
WITH SCARF JOINTS
USE ADHESIVE TO
BOND BUTT JOINTS
1-1/4” FASTENER PENETRATION
INTO SOLID FRAMING SUBSTRATE
BLOCKING AT ALL JOINTS
DIMENSION A AND B MUST BE AT LEAST 3/16”
RATIO OF A:C SHOULD BE 2:1 MINIMUM
APPLY MASKING/PAINTERS TAPE FLUSH WITH EDGES OF GAP AND
INSERT BACKER ROD.
SURFACE. A SECOND FILL WILL YIELD A MORE LEVEL RESULT.
DIMENSION B SUGGESTED MAXIMUM = 3/8”
1. To achieve optimum KOMA
mating surfaces should be clean, dry, and free from
2. We suggest using KOMA
PVC Trimwelder or a first
edge-to-edge, edge-to-face, and face-to-face bonding of
. Take caution to not over-clamp edge
to edge bonds. A film layer is necessary for strongest bond.
3. Use square cut butt joints to join KOMA
4. Fasten KOMA
trim boards securely on both sides of
should be >1/2” from end or edge of material.
Figure 6 demonstrating correct nail proximity to board to
Do not use acrylic painters caulk or silicone caulk.
They will not adhere long term and will contaminate
gaps and joints when you attempt to correct their lack
NO SCARF JOINTS
trim boards can be cut using the same saws
normally used for cutting wood; e.g., circular, miter,
radial, table, panel, band, jig, and industrial gang rip.
It is important that the cutting blades be good quality,
clean and sharp. TCT (tungsten carbide tipped) blades
with a high alternate top bevel (hiATB) or triple chip
grind (TCG) yield the best results. Choose 10” blades
with 80 teeth or 12” blades with 96 teeth for a smoother
2. Maintain a feed/rpm rate that allows for efficient chip
removal. Always position the stock so that the teeth
are cutting into the good or “finished” face.
3. Use of fine toothed scroll or jigsaw blades is not
4. Following these general work practices will
– Plastics absorb heat and care must be taken not to
overheat the work piece. Feed rates are important. Too
slow a feed rate will result in teeth rubbing rather than
cutting, creating friction and melting the chips. Rates
will vary with material thickness, geometry of cutting
teeth, and speed of blade rotation (rpm). Always run
test pieces to determine optimum performance.
– Plastics are not as stiff as some other materials.
Adequate support should be provided for the work
piece. Always secure the stock before cutting.
When rip cutting, use a rip guide or secure a straight
edge to use as a cutting guide.
trim boards do not require paint for protection
from the elements (sunlight, rain, insects). However,
when painted, PVC trim will rinse cleaner and be less
prone to attract dirt and stains that are caused
by environmental conditions.
2. If painting is desired to achieve a custom color, use a
100% acrylic latex paint with a LRV (Light Reflective
Value) of 55 or higher.
3. No special preparation or priming is required prior to
painting. The KOMA
trim board’s surface should be
trim boards do not absorb moisture. Paints will
last longer on KOMA
than on wood since moisture
5. Always follow the paint manufacturers
6. Factory finishing by independent coaters is available in
some areas. Call KOMA
technical support for referrals.
technology, most users will appreciate the immediate
and long-term adhesion advantage of KOMA
commonly cover KOMA
Celuka’s sheet and boards on
(Does not apply to KOMA free foam products)
1. Unlike free foam PVC trim products, KOMA Celuka trim
can be sanded without marring the surface. KOMA trim
may be sanded with any type of sander. To maintain
the proprietary KOMA surface texture, it is recommend-
ed to use a block or belt sander and sand in the direc-
tion of the surface grain. Use 120 grit paper and apply
light pressure. Practice on a scrap piece of KOMA until
the desired result is obtained. When it is necessary to
cut or cope KOMA at the job site for a custom fit, a belt
or pad sander may be used to smooth the edges.
1. Holes can be drilled with standard steel twist drills.
They should be sharp with an included point angle of
between 100º and 120º, a spiral angle of 30º, and a
relief angle of 10º.
2. When drilling, it is important to ensure good chip
removal to avoid overheating the hole walls and
causing a build up on the drill. This can be
accomplished by drilling with a peck or “woodpecker”
method, alternately plunging and withdrawing the drill
to clear chips..
3. Drills ground for rigid PVC are not necessary
trim boards can be routed as easily as wood
and with the same equipment and tools. Standard
carbide tipped router bits with multiple flutes work best
when using hand-held routers.
2. Dimensional consistency and uniform thickness of
trim boards enable it to be machined to tighter
milling with CNC equipment or when performing
repetitive fixture builds.
For specific tooling recommendations, feeds, and speeds,
please call technical support at KOMA Building Products
3402 Stanwood Boulevard
Huntsville, AL 35811
A Division of Kommerling USA