Continuous Insulation Addresses Problem of Thermal Bridging
Inevitably, thermal bridging is an adversary in the quest for energy-efficient buildings. Continuous insulation bolstered by a moisture barrier is a powerful weapon in the battle. Rising energy costs and a definite move toward green building accentuate the need to corral the problem of thermal bridging.
Thermal bridging typically occurs in 3 ways
- One material has higher thermal conductivity (like studs) than adjoining materials (like batt insulation)
- A thermal envelope is compromised
- There are gaps in building insulation
Thermal bridging may also create problems with condensation. Condensation can induce mold and mildew growth in wall cavities. Condensation may also generate rot and other adverse effects that cause a structure to deteriorate prematurely.
Continuous Insulation a Solution
Continuous insulation (CI) blocks thermal bridging while cavity insulation does not.
An Ohio State University study found that exterior walls with cavity insulation are typically responsible for about 17 percent of structure’s total heat loss. Thermal bridging is an even greater problem in steel-framed buildings. Cavity or batt insulation in a steel structure may reduce the R-value of the wall system by more than 50 percent.
Why is continuous insulation so effective?
First, it reduces the temperature differential between the stud and the cavity, thereby reducing heat loss normally lost to thermal bridging. Second, it keeps moisture from condensing in the wall cavity by keeping the dewpoint on the exterior. This minimizes the potential for mold and mildew inside the wall system. Third, compared to cavity insulation, continuous closed-cell foam insulation offers the highest effective R-value per inch.
Continuous insulation combined with a high performance moisture barrier offers these performance advantages:
Less water intrusion – When continuous insulation is combined with a high performance moisture barrier, there is less water intrusion, and this reduces building degradation, effectively extending the service life of the structure.
More energy-efficient building envelope – Batt-insulated walls tend to lose conditioned air through a variety of cracks and crevices. By contrast, continuous insulation blocks this passage of air which, according to studies, normally accounts for as much as 38 percent of heat transfer in a building with batt insulation.
Thinner walls – Closed-cell foam insulation has approximately twice the R-value per inch as traditional batts, thereby minimizing wall thickness, which maximizes living space and potentially reduces the volume of other building materials required.
DELTA®-VENT SA offers some distinct advantages
When looking for a high performance moisture barrier to complement continuous insulation, DELTA®-VENT SA offers some distinct advantages. It is a fully-adhered self-adhesive, water-resistant air barrier featuring four essential characteristics:
- Watertight
- Highly vapor permeable
- Aggressively self-adhering
- Highest UV resistance of any barrier
Also, DELTA®-VENT SA is the only self-adhering moisture and air barrier that offers the security of a self-adhesive edge lap. DELTA®-VENT SA maximizes the advantages of continuous insulation by eliminating leaks at fasteners and by ensuring the integrity of the overall building envelope.
DELTA®-VENT SA substantially surpasses the stringent requirements of the Air Barrier Association of America and the National Building Code of Canada based on ASTM E2357-11 , the standard test method for determining air leakage of air barrier assemblies.
DELTA®-VENT SA is a three-ply membrane:
- Top layer – Printed, spun-bonded polypropylene
- Center layer – Polymeric sheet that is vapor-permeable and yet watertight
- Bottom layer – Spun-bonded polypropylene with adhesive applied
Conclusion
Since continuous insulation covers the entire wall surface, and not just the cavities between the studs, it effectively addresses the problems of thermal bridging – of particular benefit in harsh climates with severe temperature extremes.
Continuous insulation used together with a high performance moisture barrier offers both top-notch thermal performance and the elimination of moisture penetration. Thanks to the energy-efficiency of the combination, this approach to wall insulation reduces greenhouse gas emissions.
Ultimately, opting for a wall system utilizing both CI and a moisture barrier is of increasing significance to architects, builders and contractors as building code standards are amended and upgraded.
DELTA®-VENT SA combines reliable, long-term adhesion and high tensile strength. For more information about this moisture barrier from Dörken, please contact us today.
Dörken delivers innovative, high-performance air and moisture barriers for commercial and residential construction sold under the DELTA® brand name. A North American manufacturer based out of Beamsville, Ontario, Dörken Products, Inc. is a subsidiary of Ewald Dörken AG, a leading European developer and manufacturer of waterproofing and drainage products sold worldwide. Dörken is known for delivering premium products while providing educational programs and full technical support.
