Insulation of a stone house from slipform

There can be no doubt that insulation should be of paramount importance when considering the construction of a new home. Slipform stone houses are no exception to this rule. Helen and Scott Nearing, early proponents of this stone building technique, claimed that their New England homes were comfortable year-round without much thought of insulation; in fact, his first slipform house was built directly into a Vermont bluff and made use of bare cornice as a single wall. While the thermal mass of the earth itself surely served to keep house temperatures above freezing, by modern standards there can be no doubt that this uninsulated stone house would be ideal for a cold winter. . Insulation is key to efficiency, and there are several ways to insulate a slipform stone structure.

Wall of beams and fiberglass batting

A common approach to the issue of insulation in stone and concrete structures is to build a standard stud wall against the interior wall. This framed wall is then insulated in the traditional way, using fiberglass batt insulation between the studs. While this approach works well and provides the comfort of familiarity for many builders, stud wall construction is wasteful, and the studs themselves present an opportunity to thermally bridge, significantly reducing the overall insulation of the wall. House.

rigid insulation

Rigid insulation offers a number of opportunities when it comes to insulating stone houses with slipform. Properly installed rigid insulation does not allow thermal bridges and creates an airtight envelope inside the house. There are a number of techniques for building this type of insulation directly into the walls themselves, either by placing the insulation inside the forms as you build, or by replacing the interior forms entirely with nail foundation: OSB-attached rigid insulation, wood plywood or even plaster. on one side.

Adding rigid insulation after walls are up can present a challenge for the typical homeowner/builder. The biggest hurdle here is figuring out how to secure the insulation to the stone/concrete wall. One of the best ways to do this is to use furring strips – narrow boards attached to the wall, into which screws can be driven. A powder actuated nail gun or ramset can be used to attach the furring strips to the wall. Another method is to embed the furring strips into the concrete itself as you build the walls. The downside to this approach is that the furring strips will degrade and rot over decades, leaving gaps in the wall and weakening the overall structure. Completely removing the furring strips and replacing them could be a challenge.

spray insulation

This ingenious product could be used to spray a seamless layer of foam insulation directly onto the inside of a slipform wall. The insulation would then be cut, sanded or flattened before a plaster finish coat is applied. Both of the above approaches present difficulties when it comes to hanging anything on the walls, as there are no interior studs to screw or nail. Strategically placed furring strips could be used for this purpose.

There are a number of other conventional and unconventional approaches you can take to insulate your slipform stone masonry structure, but these three options are simple to implement and proven in many homes over a number of years. Regardless of what you decide, it is very important to ensure that your slipform stone house is comfortable and well insulated.