Posted by JWmHarmon on December 18, 2002 at 12:41:42:
In Reply to: Re: Are old houses being blown down where you live? posted by steveA on December 18, 2002 at 08:10:05:
The old house I used to live in was made with oak 2X6 framing. These were true 2X4 structural members - not 1 1/2 X 3 1/2 pieces. The floor joists were true 2X12's spaced on 16 inch centers. The subfloor was made of 1X6 lumber (species undetermined, but not pine) which was actually 1 inch by six inches, not 3/4 X 5 1/2. These boards were laid diagonally forming structural triangles over the entire surface of the floor. Pine and oak finished floor boards were laid perpenicular to the floor jiosts and further triangulating the subfloor. Walls were braced with let-in braces made of true 1X4 oak boards.
If you have ever picked up a dozen oak boards, you will immediately notice the difference from a dozen fir/pine/spruce boards.
The house I used to live in was HEAVY. It was structurally braced in all planes. It was nailed with "real nails" and not the little wire nails shot from air-nailers used today. It had a rock roof - made of slate, weighing who-knows-how-much.
Compare this with the relatively flimsy materials used to build my current 1970's American stick built home with corner plywood bracing, roof trusses, and plywood floor with thin siding material.
Which house would you rather be in in a violent wind storm? The heavy as a rock older home, or the just-enough-to-hold-it-together, engineered home of the 1970's?
Why was the older home not anchored? It was so heavy that it didn't need to be anchored. The sheer weight was greater than the possible wind loads trying to blow it over.
My 1970's engineered home needed to be anchored because the weight is less than that needed to resist the wind loads. If not anchored adequately, it would blow away in a hundred-mile-per-hour gust.
When my engineered house of the 1970's proved to be inadequately designed, I repaired it with rebar and appropriate anchors. I keep hoping that we don't get 150 mile-per-hour wind gusts. I don't think it would stand. I would much rather have the old house I lived in to ride out such a storm.
Before we condemn the current codes, let's make sure that the materials and workmanship will withstand the predicted forces trying to destroy the building. We should learn something from the hurricane that destroyed Homestead Florida, and the many tornados of "Tornado Alley" in the American midwest. Maybe, just maybe, there is some wisdom behind all those codes.
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