Insuring the Perimeter of a Concrete Slab

Perimeter of a Concrete Slab

If you are building a home that is designed with slab-on-ground foundations, one of the most important things you can do to ensure good energy performance is to properly insulate the perimeter of the slab floor. The thermal boundary between the conditioned space and the ground is a major source of heat flow, and it can account for 15% or more of the overall demand for heating and cooling energy in a typical home.

The conventional path to achieving the minimum insulation required by code in this area is to install rigid foam boards at the perimeter of the concrete floor. This solution, while providing adequate performance, does not always deliver the desired results in terms of comfort and energy efficiency.

A newer alternative to this method is to insulate the top edge of the slab using a simple, inexpensive method that does not require protecting the insulation or creating exotic concrete forms. This is a technique that has been used in New Zealand for several years with great success. It uses 2-inch thick rigid foam cut to the width of the slab, and it is simply placed on top of the bottom of the 2x10s that make up the framing for the deck.

Insuring the Perimeter of a Concrete Slab

This method of insuring the perimeter of the slab is not only more comfortable, but it also reduces the operational energy that must be expended to keep a room temperature at a desirable level. It is not hard to see why this type of insulation is now considered an important part of any energy-efficient design.

While there are other options for insuring the perimeter of a concrete slab, such as wire mesh or steel rebar, these materials tend to add cost without adding any real strength and can create a dangerous fall hazard for construction workers. The safest approach is to use a system like J-Safe that provides effective, non-penetrating, temporary concrete slab edge protection.

J-Safe offers a range of systems that meet and exceed the European standard BS EN 13374 for temporary slab edge protection. The components are easily positioned on the concrete using a special bracket that is secured by nailing to the concrete. The safety posts and barriers are then held stable by a cast-in anchor that is embedded in the concrete at maximum 2,400mm spacings.

To determine the correct placement of the J-Safe concrete slab edge protection, it is recommended to utilize Grids and Construction Grids to generate SnapTo points for the slab framing and to specify a Slab Overhang value of 0.0. The Layout – Slab – Slab Edge command may then be used to define the slab edge polygon for the entire layout. This command cannot be used when the floor framing is not fully defined, such as when the slab edge cuts into the structure of the building. In this case the Whole Perimeter command is usually more useful.