Installation Guide

Conrm sealant is within its shelf life and review sealant
precautions prior to application.
It is recommended to remove old or damaged sealant
from a joint prior to installing new sealant. Remove
sealant by cutting away product with a knife or razor and
follow steps below for preparing the substrate. NOTE:
Old silicone sealant must be completely removed as it
will aect adhesion of newly applied sealant or could
cause areas of failure.
Substrate preparation should be completed on the same
day of sealant application. Surfaces must be clean (free
of any material that may prevent adequate adhesion),
stable (substrate must be able to handle joint
movement), dry (free of ice, frost and standing water)
and primed (if required by sealant or needing additional
substrate stabilization) prior to sealing. Be sure to test
any product on the substrate for compatibility before
installation.
Surface sealers and coatings often end up repelling
sealants. Whenever possible, sealers and coatings
should be applied after the sealant is cured, as it is
extremely dicult to apply such materials onto the
surface without contaminating the joints.
If you would like to install a butt joint, be sure to correctly
determine joint movement, due to its high risk of joint
failure when not properly designed.
3
STEP
Prior to Installation
Prior to Installation
3
STEP
Allowing for joint movement is necessary because all
substrates will move due to temperature expansion and
contraction. Joint movement measurement is critical to
determine the type of sealant to use, if the sealant is
capable of performing as expected and to ensure the
joint will properly expand and contract in adverse
weather conditions.
STEP
STEP
1
1
Analyze Joint Movement
Analyze Joint Movement
Environmental stresses such as UV light, temperature
extremes, humidity/moisture levels, physical stress
and other variable loads all aect joint performance.
ASTM C920 can be used to determine if the sealant
has enough “stretch” to handle the dynamic joint in
question. ASTM C920 incorporates a number of tests
that determine cyclical movement on a number of
substrates, accelerated weathering, peel strength,
staining and fade resistance. Some sealants will work
better than others on certain substrates. See specic
product details to determine which sealant is best for
your desired application.
STEP
STEP
Capabilities
Capabilities
2
2
Joints that are too narrow for joint movement will push sealant out during
substrate expansion or split from too much expansion during substrate
contraction which may cause leaks.
Wide joints can handle more movement but need backing material to form a
seal not thicker than 1/2” with large attachment areas on each substrate.
Do not ll nail holes. Do not tool, smear, feather or wipe the bead to a thin
consistency or it will need to be painted.
High relative humidity will slow the cure for water-based sealants.
Cold, dry air will slow the cure for moisture-cured and solvent-based sealants.
H
ot, humid conditions will cause moisture-curing sealants to skin more quickly.
Hot, dry conditions will cause both water-based and solvent-based sealants to
skin more quickly.
Frost conditions can deter adhesion of the sealant to all substrates.
Wet conditions (areas with standing water) should be dried to allow for sealant
contact with the substrate surface.
Troubleshooting
Troubleshooting
Backing materials such as open cell, closed cell, bicellular
backer rods or bond breaker tape/backing tape are used
to control the depth and shape of the sealant. Backing
material functions as a bond breaker to eliminate
three-sided adhesion, helps shape the sealant to allow for
less stress on substrates during joint movement and
allows the sealant to expand and contract properly.
Backer rods should be approximately 25% wider than the
gap and should be rmly placed at a consistent depth not
less than 1/8" and not to exceed 1/2" in thickness. The
backer rod helps push sealant against the substrate to
create a larger bonding area.
Bond breaker tape should be used where the joint is too
shallow to t a backer rod. The bond breaker tape will need to
be sized appropriately. If it is too large, the tape will wrap
around the sides of the joint eliminating bonding area required
for proper adhesion.
Open-cell backer rods should not be used where moisture
absorption into the backer rods can be a problem, including
horizontal and submerged joints. Closed cell backer rods
should be inserted using a blunt tool to avoid puncturing it
as this could cause bubbling in the sealant.
Joints should be completely lled with sealant to ensure
there are no air bubbles. If no backer rod is used, be sure
sealant has adhered to both sides of the joint.
STEP
4
4
Filling the Joint
Filling the Joint
STEP
Tooling is used to shape the sealant (See ideal bead
section). Tooling may not be recommended for all
sealants, see specic product directions. All directions on
the product label should be followed as described. When
tooling, only use aides such as water, soap or oils
sparingly as they an aect curing. Feathering a sealant can
cause premature aging or a color change. If feathering is
required, painting should be considered.
Tooling
Tooling
5
5
STEP
STEP
Clean uncured polymer-based sealants with acetone or
isopropyl alcohol. Follow solvent vendor’s precautions
when using solvents. Clean uncured water-based sealants
with water. After curing, excess sealant must be cut or
scraped away as they are dicult to remove.
Cleanup
Cleanup
6
6
STEP
STEP
Make sure to vary your wait time based on the humidity
level, as reactive sealants will cure slower when it is cooler
and less humid, and water-based sealants will dry slower
when it is cooler or more humid. Once a skin is formed
bead can be tested for durability and may be painted over.
Check specic product information for preferred type of
paint, how long to wait after application before applying
paint, and if compatibility tests are recommended for paint.
Cure Time and Paintability
Cure Time and Paintability
7
7
STEP
STEP
THREE-SIDED ADHESION
AVOID THREE-SIDED ADHESION