Furring vs. Framing
At first glance, furring and framing appear slightly similar. Both involve installing wood members, evenly spaced, to which the builder can attach other construction materials. The two processes, however, are actually quite different. Framing provides the skeleton of the structure, while furring does not bear weight and requires an existing surface for installation.
Frame construction is the standard method by which most houses are built. Framing, also called stick framing, is the second stage of the building process, following the construction of the foundation. A framing crew uses dimensional lumber to build a floor joist system, erect walls and set roof rafters, in that order. Framing includes building both load-bearing and non-load-bearing, or partition, walls.
The purpose of furring is to extend something such as a wall, to increase rafter or joist depth, to provide a nailing surface for attaching sheet materials, shingles or siding or to comply with insulation codes. Furring strips can be thin wood pieces or full size dimensional lumber. The size of the furring strips used depends on the reason for extending the wall or other framing. Furring relies on an existing structure to support it, and furring can be installed directly to a masonry or wood-framed surface.
Framing Uses and Methods
Local building authorities regulate framing to ensure safe homes and buildings that withstand environmental conditions and the weight of the structure above. While there are various framing techniques, such as constructing walls lying down and then standing them up, or, alternately, building them in place, all framing should comply with building codes. Nearly all of today’s framing follows accepted building practices that include uniform spacing of joists, studs and rafters to accommodate the installation of standard-size sheet materials, such as drywall, subflooring and roof decking.
Furring Uses and Techniques
While there are no structural requirements for installing furring, the strips are usually attached at the same space intervals as framing members for ease of attaching sheet material. For example, if a homeowner wants to insulate a concrete block house, he might install furring strips on the interior of the walls, spacing them 16 or 24 inches apart so standard four-by-eight sheets of drywall would fit. He could use two-by-four wall studs, flat, as furring strips, which would provide a 1.5-inch depth between the strips for foam board insulation. Furring can install perpendicular to the framing, such as adding horizontal furring to a roof deck before installing cedar shingle. Furring can also install along existing framing members, such as adding two-by-four furring strips to the bottom of roof rafters to create a deeper rafter space for insulating.