Expansion Joints and Pre-Compressed Sealants
R-Value of EMSEAL
Precompressed Foam Wall Joint Sealants
Tested in 2009 in accordance with ASTM C518-04 “Standard Test Method for
Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter
Apparatus”. All values in
SI units using:
1 K·m²/W = 5.678263 h·ft²·°F/Btu
per 1-inch (25mm)
R-Value at Standard
Depth One Side of Wall
(50mm) Nominal Material at Mean Temperature Joint Width
2-inch (50mm) Nominal Material with Standard Depth Both Sides of
*Extrapolated from tests of
similarly constituted products--individual tests pending.
R-Value of the uncompressed base foam of which COLORSEAL,
and BACKERSEAL are comprised is R-3.28/inch of depth. As density increases
R-value decreases. As layers of uncompressed foam are compressed to form
the supplied product, the resulting R-values are as stated in the table
would fluctuate up and down slightly from this value depending on movement
at the joint caused by thermal cycling. The R-value would decrease in
summer when the joints close up. In contrast, R-value would increase in
winter when the joints open thereby lowering the foam density of the
material in question.
Expansion Joint and Sealant Selection Costing Your Client a Fortune?
Thermal rating of structural expansion joint seals is seldom among product
selection criteria. Yet the product chosen to seal large structural
expansion joint gaps could be setting the R-value for your entire exterior
is because, as was pointed out in “Exterior Wall Systems, R-Value, and
Revenue” by Tom Kuckhahn published in the September 2003 Construction
Specifier, heat “seeks the path of least resistance, so the R-value of
an actual wall is closer to the R-value of the least insulating portion of
Kuckhahn continues, “Energy is one of the most significant expenses for
commercial facilities, particularly for heating and cooling, which represent
about 32 percent of a building’s operating budget.” This means that
designers concerned with sustainable, green, or simply efficient design
should make energy use their top priority in material selection.
Strip seal: invasive screw anchors and
aluminum rails create a thermal bridge at expansion joints, while rubber
barriers are not air-tight nor do they insulate.
Among the choices for structural expansion joint sealing in walls are strip
seals and pre-coated, pre-compressed, impregnated foam sealants.
Seals” are metal (usually aluminum) rails, mechanically anchored to joint
substrates into which are snapped rubber bellows sealing glands.
Strip Seals violate good thermal design in a number of ways.
First, the thin rubber bellows impart little in the way of thermal
Second, the metal rails create thermal bridges in the wall system in the
same way that wall ties and other non-insulated conductive materials do.
SEISMIC COLORSEAL in
insulated precast wall panels ensure continuity of insulation across
Pre-compressed, Impregnated Foam Sealant (SEISMIC COLORSEAL by EMSEAL) is an open-cell polyurethane
foam, impregnated with water-based acrylic sealant, and factory coated with
low modulus silicone to create a movement bellows.
The R-value of
is 2.15 per inch of depth.
This means that on a typical 3-inch joint, the
R-value at the structural joint gap of a wall sealed with
x 3.5 (the depth of seal of 3-inch SEISMIC COLORSEAL) = R-7.52.
both sides of the wall, this value willdouble to R-15.04
excluding the R-value of the air-space created between the two pieces of
Design flexibility is
further extended through the option to customize the depth. With each
additional inch of depth, you are adding more insulation.
double-Sided SEISMIC COLORSEAL provides the option to seal both faces of
a wall system in a single step.
Finally, because COLORSEAL contains no metal and attaches to substrates
without invasive metal anchors, it does not create any conductive thermal
bridges in the wall system.
now with the advent of
DFR2, not only can you seal and insulate the building, but you get a UL
certified product with
UL 2079 2-hour
fire rating all-in-one.
Kuchahn rightly observes, “decisions made during design and construction
stages affect the cost and performance of buildings for decades to
come-especially in terms of energy consumption.”
seems to make sense then, that independent-lab-certified thermal rating be among the criteria for
specification and acceptance of structural joint sealing materials.
John Ruskin, a nineteenth-century commentator
on architecture among other things warned:
“It is unwise to pay too much, but it’s worse
to pay too little. When you pay too much you lose a little money—that
is all. When you pay too little you sometimes lose everything, because
the thing you bought was incapable of doing the things it was bought to do.
The common law of business balance prohibits paying a little and getting a
lot. It can’t be done. If you deal with the lowest bidder, it is
well to add something for the risk you run, and if you do that you will have
enough to pay for something better."
EMSEAL JOINT SYSTEMS LTD. 25 Bridle Lane, Westborough, MA 01581 EMSEAL LLC. 120 Carrier Drive, Toronto, ON M9W 5R1