Dicor EPDM ROOFING SYSTEM RETRO-FIT INSTALLATION GUIDE
The instructions contained herein are guidelines for installing Dicor
EPDM rubber roofing on older RV’s. When applied using the proper
techniques, materials, and tools, the D roof should provide years of
dependable, trouble free performance. To ensure proper warranty
coverage, you should adhere to the installation techniques and materials
described in this installation guide. Use of other procedures and
products may jeopardize your warranty coverage.
Note: Read fully and understand the procedures before beginning installation.
Tools and Materials:
A. Waterbased adhesive (901-BA) is applied to a wood substrate with a
roller. The BRITE-PLY roofing is applied while the adhesive is still
B. Butyl tape (BT-1834) must be under all vents and accessories on the
roof and termination moldings that contact the EPDM roofing. Butyl tape
should also be used under the EPDM membrane where it comes in contact
with the unit body at the front, rear, and side terminations.
C. Lap sealant (501-LS) is a self-leveling caulk used to seal screw-type
fasteners and termination moldings, formulated especially for Dicor
D. Paint roller (not supplied) should be 9” wide short nap type. Used to apply waterbased adhesive (901-BA).
E. Push broom or squeegee (not supplied) used to remove air pockets and
ensure that the EPDM membrane is completely in contact with the
F. Caulking gun (not supplied) used to apply lap sealant (501-LS).
G. Roof decking (substrate, not supplied), depending on the roof load
requirements, should be at least 1/8” luan plywood. If the load
requirements are heavy (storage pods or consistent traffic) a minimum of
1/2” plywood is recommended. In most new unit applications, 1/4” luan
or plywood is the minimum material used, while 3/8” material is more
NOTE: Dicor does not warrant selection of substrate material. Feel free to contact Dicor with any questions.
You will notice a powdery, white talc on the surface of your Dicor EPDM
roof membrane. This talc is used in the manufacturing process of the
membrane. While this talc will not interfere with the performance of
your EPDM roof, and it will eventually be removed by the natural
elements, it is recommended that you clean the membrane within a week
EPDM roofing can be cleaned with Dicor Rubber Roof Cleaner. For
stubborn stains, products containing mineral spirits are recommended.
Do not use Acetone or Citrus Cleaners.
Do not let any cleaning solvent come in contact with the membrane for
extended periods of time. Because dust and dirt may collect on the roof,
regular cleaning with Dicor’s RP-RC160C or RP-RC320S Rubber Roof
Cleaner is recommended. Do not park vehicle for extended periods where
roof will be exposed to tree sap or fruit as staining may result. A soft
bristle brush may be used during cleaning.
1. Remove all appliances, vents, moldings, etc. that may inhibit the current roofing material from being removed.
2. Evaluate the old roof. EPDM roofing must have a sturdy foundation.
Determine if the entire roof should be removed, or if the addition of
decking (substrate) will be sufficient. Remember that the substrate must
be securely fastened on all edges and seams.
3. Either remove the old roof or apply the substrate over the old roof, if removal will create structural damage.
4. When applying the substrate, make sure it extends to the edges of the
roof. Also, make sure all seams are tight and as level as possible. The
substrate should be applied using screw-type fasteners with screw heads
level or slightly below the surface of the substrate. All substrate
seams should be on a rafter for necessary support and to reduce the
possibility of “seam separation”. If seams are wider than 1/16” you may
want to bridge seams with Dicor Fleece Tape 511FT. Additionally, if on
the roof edge, the membrane will be going over a sharp edge, you should
either bevel the edge of the substrate with a sander or place the Dicor
Fleece Tape 511FT over the edge to protect the membrane from the edge.
5. Route-out or cut all vent and appliance openings.
6. Broom or blow-off of substrate all foreign materials and check entire
roof for exposed screw heads or sharp objects that may prematurely wear
the EPDM roof.
1. Locate the ends (front and rear) where the EPDM roof will be
terminated. Use a chalk-line to mark these areas. Make sure there is
sufficient roof structure to fasten to.
2. Cover the roof with the EPDM membrane making sure there is sufficient
length at both the front and rear termination points. Fold membrane
in-half, exposing the roof areas.
3. Open the waterbased adhesive (901-BA) and stir thoroughly. Using a 9”
wide short nap paint roller, apply adhesive to the substrate at a rate
of 160 sq. ft. per gallon. The membrane is to be mated with the adhesive
as quickly as possible.
4. Fold the membrane the opposite direction and repeat step #3.
5. With the membrane in place, adjust to make sure there is sufficient
length at both termination points and on both sides of the vehicle.
Remove wrinkles by lifting and pulling the membrane. Do not stretch the
6. Lightly squeegee or broom to eliminate air pockets, making sure the membrane is completely in contact with the adhesive.
7. Apply butyl tape (BT-1834) to the side of the roof edge molding.
While holding the molding, draw surplus material tight with a downward
pull. (You may staple the membrane in-place spacing 1/2” staples 3-5”
apart to keep proper tension.) For best results, install this molding
from the center of the vehicle toward the ends. When complete, use a
utility knife to cut surplus material from below the molding. Repeat on
NOTE: It may helpful to strike a chalk line to assist in keeping the side-body molding straight and in proper position.
8. Apply butyl tape (BT-1834) to the termination molding. On the
front, the front cap should lay on top of the membrane. Using a
screw-type fastener, install the termination moldings – making sure
there is sufficient roof structure. On the rear of the vehicle, the
membrane should lay on top of the rear cap.
NOTE: Butyl tape should also be used under the EPDM
membrane where it comes in contact with the unit body at the front,
rear, and side terminations. See all termination drawings for correct
9. Using a utility knife “X” cut all roof openings. Make sure all
openings are cut the same size as previous openings. Round all 90 degree
cuts to eliminate “running cuts”. Surplus material should be stapled
inside vent openings. Do not stretch the rubber membrane. Trim all
10. Apply butyl tape (BT-1834) to all appliances, vents, etc. Re-install
using screw-type fasteners. When installing the vents, appliances, etc.
you may notice that the EPDM membrane near the screws begins to “creep”
and small air pockets form. Simply “walk” the bubble toward the opening
and hold-in-place while installing screw-type fasteners.
Caulk all screw heads, front and rear termination bar and all accessories.
Note: Only Butyl Tape can be used with Brite-Ply membrane to assure proper seal.
11. Install lap sealant (501-LS) using a 1/4” to 3/8” bead, as follows:
A. Bridging the membrane on all appliances.
B. Both ends of the front and rear termination molding.
C. Top edge of side roof edge molding.
D. All screw heads located on the roof.
NOTE: Do not use silicone – it will not adhere to the EPDM rubber.
12. Clean all surplus caulk and debris from the roof.
NOTE: If the unit has a fiberglass or metal side radius
cap, a bonding adhesive may be used in these areas. Normally, pulling
the membrane tight under the side edge roof molding will be sufficient.
If you determine a bonding adhesive is necessary, please call Dicor for
Proper care and maintenance of your recreational vehicle,
including your EPDM roof, is important for trouble-free performance.
Normal maintenance is simple, easy, and requires no special material.
Keep your roof clean. Clean your roof at least four (4) times annually.
For normal cleaning:
– Use Dicor Rubber Roof Cleaner RP-RC160C concentrate to clean
complete roof or RP-RC320S ready to use cleaner in a spray bottle for
smaller areas. (See CAUTION below.)
– Rinse complete roof with clean water to remove any loose dirt or debris.
– Using a medium bristle brush, along with the cleaner mixed with 2
or 3 gallons of water, scrub the entire roof. Rinse thoroughly with
clean water to avoid residue build-up on the roof or sidewalls of the
– For more difficult stains, you may use RP-RC160C in its original
concentrated form. For stubborn stains, use a cloth dampened with
mineral spirits. DO NOT use mineral spirits in a large area or allow it
to soak into the membrane.
CAUTION: DO NOT use cleaners or conditioners containing petroleum
solvents, harsh abrasives, or citric-based cleaners. You may cause
irreparable damage to your roof and/or may void your warranty. Use
caution when working on top of your vehicle. The wet membrane may be
Beware of areas where fruit, tree sap, or harsh environmental fall-out may stay on the roof for an extended period of time.
These conditions may result in irremovable stains. If you are in these
conditions, you may have to increase the frequency of your cleaning.
OTHER HELPFUL INFORMATION: – Dicor EPDM roofing
membrane is specially formulated for exposure to the sun and natural
elements. However, it can be cut or punctured by sharp objects. Use
caution when placing any articles or walking on the roof. If damage does
occur, the membrane can be easily repaired using Dicor’s #401-PR or
#402-PR roof repair kits. Contact your local dealer or Dicor
– Cleaning lap sealant used around roof mounted accessories and
railings: If soap and water do not clean the seal to your satisfaction,
use a cloth dampened with mineral spirits to wipe away dirt build-up on
– Repairing lap sealant or adding sealant: If, after a period or
time, the lap sealant needs touched-up or additional seal is needed, use
a cloth dampened with mineral spirits to eliminate all foreign
materials from the surface of the seal, let set for at least 15 minutes
and apply Dicor lap sealant (#501LS, #502LS, #551LS) directly over the
existing seal – allowing the new sealant to touch the EPDM and/or
– If additional UV protection is desired, apply Dicor’s RP-RG320S Rubber Roof Guard Protectant immediately after cleaning.
CLEANING MOLD AND/OR MILDEW FROM RUBBER ROOFING MATERIALS NEEDED:
- BUCKET OF WATER
- MEDIUM BRISTLE BRUSH
- TILEX BATHROOM CLEANER
There are no ingredients in EPDM rubber roofing that will promote the
growth of mold and/or mildew. Atmospheric dirt, shade, sun, humidity
and moisture are some of the contributing factors that form mold and/or
mildew. Regular cleaning of your rubber roof will help prevent mold
and/or mildew from forming on the EPDM roof. Dicor recommends that you
wash your roof an average of 3-4 times a year using a non-abrasive
cleaner and a medium plastic bristle brush. Mold and/or mildew on your
EPDM roof is simply a parasite that attaches itself to the roof and
grows – similar to bathroom mold that grows in your shower. It does not
attack the membrane but is unsightly and if allowed to grow will
discolor the roof completely and may become a stain that cannot be
Please note, the removal of mold and/or mildew is not a job
to be rushed. Allow ample time to complete the job and follow
instructions carefully. Although the products mentioned will not harm
your roof, if you do not follow the instructions, other areas could be
Tilex is a bathroom cleaner that can be purchased at many grocery
stores or discount stores. Tilex contains strong chemicals. Please
read the label thoroughly. Tilex should not come in contact with
painted or aluminum surfaces. If it drips over the sidewalls or comes
in contact with painted or aluminum surfaces, wipe immediately with a
WORK WITH A SMALL AREA in order to maintain
control. Spray a small area approximately 2’x2′ with the Tilex. Allow
the Tilex to remain on the roof for 3-10 minutes per area. Scrub with a
medium bristle brush. After scrubbing, wipe with a damp sponge.
When finished with whatever time frame you intend to spend on the roof (whether you do the entire roof or just a portion)
rinse the roof thoroughly with a garden hose. BE SURE TO RINSE WINDOWS AND SIDEWALLS ALSO.
Most often one application is all that is needed to alleviate the
problem. Depending on the amount of mold and/or mildew and the length
of time growing, more than one application may be necessary.
Follow this procedure with the Dicor Roof Gard (RP-RG320S) protectant.