| Here
are some frequently asked questions about designing with the
THERMOMASS Building System. Click on the links to the left
to read questions and answers for other topics of interest
for the THERMOMASS Building Insulation System.
If you are having
trouble finding all of the answers to your questions about
THERMOMASS, please contact
our technical services department via email or call us
at (800) 232-1748. We can help
you with the choices involved in building with insulated concrete
panels. |
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What is the connector spacing? |
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How is this spacing achieved in the field or
plant? |
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What does the connector designation mean? |
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How do I determine which connector to use? |
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What thickness of insulation can be used? |
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What is the minimum thickness of a typical face
(exterior) wythe? |
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What is the typical structural (interior) wythe
thickness? |
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What thickness and combinations are available
for vertically cast walls? |
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Are the connectors visible on the face of the
panel? |
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What types of concrete finishes are possible? |
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What about reveals and designs? |
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Will solid concrete edges affect the panel? |
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What can I do if I must have a solid concrete
section? |
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What covers the exposed insulation at openings? |
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| For many applications, the connectors
are spaced 400mm (16”) on center in both directions.
Depending on panel dimensions and loading conditions, the
spacing may be adjusted. |
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| Insulation boards are supplied with thermally
pre-punched holes at the proper spacing |
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| There are two series of connectors: MC (Metric
Common) and MS (Metric Short). The MC series connectors have
50 mm (2 in) embedments into both the interior and exterior
concrete wythes, while the MS series connectors have 38 mm (1.5
in) embedments. The four digits following the two-digit designation
indicate the insulation thickness: The first number is the insulation
thickness measured in inches, multiplied by 10. The second number
is the insulation thickness measured in millimeters. |
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| All connectors have a molded collar with
a length corresponding to the insulation thickness. The MS
series is designed for panels in which one or both concrete
wythes are 50mm to 63 mm (2.0” to 2.5”) thick
(minimum recommended thickness). If both concrete wythes are
63.5mm (2.5”) or more in thickness or if the depth of
the reveals in the panels allow a net thickness 2.0”
or greater, then the MC series connectors should be used. |
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| Insulation thickness values ranging from
25mm (1”) to 250mm (10”) have been used successfully.
The minimum recommended thickness is 38 mm (1.5”) for
horizontally poured panels and 50mm (2”) for vertically
poured walls. A thickness greater than 75mm (3”) is
normally built-up from multiple layers of insulation.
The required insulation thickness can be determined using
a thermal analysis that incorporates consideration of the
building use, location and potential vapor drives in low temperature
applications. |
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| A minimum thickness of 50mm (2”) is
recommended. This will provide 12.5mm (1/2”) cover over
the end of the shorter (MS) connectors. The thickness of the
wythe should be increased from this minimum by adding the depth
of any architectural reveals, where required, into the face
wythe. |
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| The thickness will vary as a function of construction
method and building loads. For precast, prestressed, and modular
precast applications, the manufacturer should be consulted.
For tilt-up applications, an initial value can be estimated
using a height/thickness ratio of 50. The final thickness must
be set by the engineer of record considering erection, gravity
and lateral forces. |
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Wall thickness can range from 125mm to
350mm (5” to 14”) or more, depending on insulation
thickness and system configuration.
Standard wall configurations* for poured-in-place construction
are 100mm/50mm/100mm (4”/2”/4”), and 125mm/50mm/125mm
(5”/2”/5”), and 150mm/50mm/150mm (6”/2”/6”).
The minimum thickness of concrete in a wythe is determined
by practical limitations of pouring a concrete wall. The insulation
can be fixed at any location within the wall.
* concrete/insulation/concrete |
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For horizontally cast panels, the recommended
12.5mm (1/2”) cover will conceal the connectors. In
vertically poured wall construction, the connector is provided
with a 1/8” space between the connector end and the
form or form liner, however, some connector ends will be at
the surface.
If a connector end is at the surface, there should be no
concern. The connector is fabricated with a gray color and
appears as a piece of aggregate. In addition, the coefficient
of thermal expansion of the fiber composite connectors is
the same as hardened concrete and is non absorptive, thus
eliminating spalling that otherwise might occur if a less
compatible material were used. |
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| It is up to the capabilities of your local
wall producers. The THERMOMASS Building Insulation System can
be used with any type of forming system, with or without form
liners. Finishes can include natural concrete, paint, skim coat
plaster, sandblasted, concrete exposed aggregate, thin brick
or most forms of concrete treatment. Other materials may be
secured to the wall with concrete anchors. |
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| There is no limit to the design possibilities
when making a panel in a form. Reveals, embossed logos and dimples
in the finish are just a few examples. In fact, for a nominal
charge, Composite Technologies Corporation can supply polystyrene
molds for replication of almost any logo produced using a CAD
drawing. |
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| Solid concrete edges will cause thermal bridges.
Perhaps more importantly, however, they will restrict the exterior
face from moving independently of the interior face in response
to temperature changes. This will create stresses within the
exterior face resulting in non-structural cracking and may cause
panel bowing. |
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| There are a variety of methods for reducing
the potential for the two layers of concrete to become monolithically
connected. Solutions are available through our technical department
for specific conditions. |
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| Window and doorjambs can be used to cover
the insulation wherever possible. They should be attached to
one (usually interior) wythe of the panel. The other joint should
be sealed with caulk to allow for movement. Other options are
available through our technical department for specific conditions. |
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What is THERMOMASS?