When it comes to design flexibility, speed of installation, and energy-efficiency, tilt-up concrete construction offers the complete package. And with heating and cooling costs typically representing around 30% of a building’s annual operating costs, the energy-saving benefits of tilt-up are worth a second look.
R-values and tilt-up concrete panels
The R-value is simply a measure of resistance to heat flow through a given thickness of material. At its most basic, the higher the R-value, the greater the resistance. But when it comes to the true effectiveness of an insulation material, its R-value is only part of the story.
The standard R-value of ready-mix concrete used in the Tilt-up industry – including the air film – is 1.49 for an 8-inch wall panel. However, since it’s easy to add insulation to any Tilt-Up panel this number can rise substantially.
The 3 most common insulation methods for tilt-up concrete construction
Tilt-Up panels can be insulated using several different methods, depending on the project specifications and building energy codes. The 3 most common insulation methods are described below:
Applied Insulation Systems
Surface-applied insulation systems can be applied to the interior or exterior of the tilt-up concrete panel, and typically result in R-values ranging between 5 and 15.
Interior applied insulation systems are usually attached with Z-type spline to hold the insulation in place. This system isolates the concrete on the ‘cold’ side of the wall, which can decrease the thermal mass.
EIFS (Exterior Insulation Finishing Systems) are a commonly-used exterior system. In this process, insulation is covered with cementitious coating, making it easy to add architectural features.
Integrally Cast Insulation Systems
Insulation can also be imbedded into the down-side or top-side facing tilt-up panel.
Integrally-cast face insulation systems positioned against the down-side face are predominantly EPS (expanded polystyrene) in nature, which facilitates the interlocking with the concrete. EPS insulation works as a substrate for the EIFS process, offering a range of insulation thickness to meet any R-value.
The top-side panel often uses the more rigid XPS (extruded polystyrene) insulation and a metal stud frame.
Concrete Sandwich Panels
This is the most popular insulation method, since sandwich panels can serve both a structural and thermal function.
As the name suggests, a sandwich panel insulation system consists of two wall panels – the interior surface and exterior façade – separated by a layer of ridged insulation.
The two walls, called concrete wythes, are connected by ties through the insulation, which typically spans two pours – the exterior wythe pour and the installation of the interior concrete reinforcing.
The R-value achieved by sandwich wall panels can vary widely; greater R-values are achieved by increasing the thickness of the insulation between the two concrete wythes. Sandwich panels with up to 10-inches of insulation can achieve R-values as high as 50.
The R-value will also be affected by the type of insulation used. Extruded polystyrene (XPS) is much stronger and has a higher R-value than expanded polystyrene (EPS). Other moisture absorbing insulations should not be used.
Sandwich panels can be fully, partially, or non-composite. In composite panels, the two layers are connected as an integral unit. Partially-composite panels use rigid connectors, while non-composite panels use steel, molded plastic, or composite ties.
5 reasons to choose insulated concrete wall panels
Regardless of the method used, an insulated Tilt-Up concrete wall panel system can provide a complete building envelope, including the exterior membrane, moisture barrier, insulation, and interior finish. No need to coordinate multiple trades to complete the separate wall elements.
In many buildings, insulated concrete wall panels can replace structural elements like columns and truss systems. This reduces costs and leads to greater design versatility.
Insulated concrete Tilt-Up wall panels create a tight building envelope, resulting in a highly energy-efficient building.
An insulated concrete wall panel system is designed to provide a service life of around 75 years, with very little ongoing maintenance.concrete
Concrete is inherently more fire resistant than other building materials, which often results in lower insurance costs.
Tilt-Wall Ontario has more than 15 years of tilt-up construction and design experience. Contact us to find out more about the benefits of tilt-up construction.