Wondering Which Is The Better Way To Build; Framing Or Masonry? Here Are Some Answers.
I am often asked by my clients if we should use a masonry exterior wall or one that is framed in wood.
Masonry walls consist of concrete blocks stacked up from the slab to the full height of the wall. They are placed in beds of mortar and strengthened with embedded reinforcing steel and hollow cores full of concrete. The strength is dictated by wall thickness, height and density of reinforcement and, of course, loading conditions. Framed walls consist of wood studs usually 16" on center with a stiff sheathing material, water proofing and some sort of siding on the outside such as stucco or siding. Let me answer a few common questions:
Can termites be a problem in wood framed homes?
If the framed wall is built correctly the answer is "no". Pressure treated plates are used at the bottom of the wall. Termites hate PT wood and won't eat through it. Also termite shield should be used. This is like flashing and is placed under the wall and extends out to block passage of subterranean termites in their attempts to travel up the wall. Those and routine maintenance, after construction, such as inspections and treatment allow homes to last a long time. There are many framed homes that are several centuries old which stand as proof that such construction methods are valid.
Is a masonry wall stronger than a framed wall?
In general, a framed wall can be built with adequate strength to handle hurricane winds and other forces. A wooden wall with proper sheathing, nailed properly, is quite strong. A masonry wall is also quite strong. Its strength is a function of its thickness, its height as well as the reinforcement used.
What about Cost? Would masonry or framed walls be cheaper in the long run?
Siding for a framed home can cost more than the typical stucco finishes used over block walls. However other factors, including speed of construction, cost of materials and labor tend to make framing an overall less expensive approach.
What about insulating masonry walls and framed walls?
Insulation is always a challenge with masonry walls. The blocks themselves are not good insulators. Insulation is usually achieved by placing a foil over the pressure treated furring strips, or foam sheets over the wall and can even include filling the cores with insulation. None of these achieve insulation as high as that achieved in a wood wall. Wood framed walls are usually insulated with batts ranging from R-11 right to up in the 20's, depending upon wall thickness. Wood is generally easier to insulate to higher levels. One advantage of masonry is that it has a higher thermal mass which will tend to regulate temperatures a bit better.
Does the relative thickness of masonry walls take up more room in the house?
If one uses a standard 8" masonry block and compares it to a typical 2x4 exterior wall, one can instantly see about a 5" different in the amount of each exterior room that is taken up by the wall. Framing does take up less room.
These are just a few factors to consider. Framing the exterior walls of a home is an excellent way to proceed. Interestingly, most homes that I design are masonry because most folks tend to feel more comfortable with masonry walls. There is a perception of additional strength. But, frankly, the facts indicate that this is a false sense. If done properly (and it is important that it be done correctly) framing is a better value.
