There is no doubt that insulation should be of primary importance when considering the construction of new homes. Slip-form stone houses are no exception to this rule. Helen and Scott Nearing, the early proponents of this stone building technique, claimed that their New England homes were year-round comfortable without much thought about insulation; in fact, his first slip-form home was built right on a Vermont cliff and used as a bare ledge as a wall. While the earth’s thermal mass certainly served to keep house temperatures above freezing by modern standards, there can be no doubt that this uninsulated stone house would make for a cold winter. Insulation is key to efficiency and there are several ways to insulate a slipform stone structure.

Fiberglass padding and stud wall

A common approach to the issue of insulation in stone and concrete structures is the construction of a standard truss wall against the interior wall. This framed wall is then insulated in the traditional way, using fiberglass batting insulation between the studs. While this approach works well and brings the comfort of familiarity to many builders, post wall construction is wasteful and the posts themselves present the opportunity to create thermal bridges, significantly reducing the overall insulation of the home. .

Rigid insulation

Rigid insulation offers a number of opportunities when it comes to insulating slip-form stone houses. Rigid insulation, properly installed, does not allow thermal bridges and creates an airtight envelope within the house. There are a number of techniques to build this type of insulation directly into the walls, either by placing the insulation inside the forms as you build, or by replacing the interior forms entirely with nail base: rigid insulation coupled with OSB, plywood or even plasterboard. on one side.

Adding rigid insulation after walls are up can be challenging for the typical homeowner / builder. The biggest hurdle here is figuring out how to secure insulation to the stone / concrete wall. One of the best ways to do this is by using furring strips, narrow boards fixed 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 approach is to embed the screed 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.

Aerosol insulation

This ingenious product could be used to spray a seamless layer of insulating foam directly onto the inside of the slipform wall. The insulation will then be cut, sanded or crushed before applying a finish coat of gypsum board. Both of the above approaches present difficulties when it comes to hanging something on the walls, as there are no interior studs to screw or nail. For this purpose, strategically placed furring strips could be used.

There are many 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 several years. Whatever you decide, it is very important to make sure your slipform stone house is comfortable and well insulated.