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RE: Field Observations - Stupid things I've seen

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John Ott,
Commercial transport airplanes are designed with a 1.5 Factor of Safety (ratio of ultimate load to limit load).
Steve Smith, PE, SE
Systems Stress
(425) 294-7681
M/S 02-56

> ----------
> From: 	JohnOttCE(--nospam--at)[SMTP:JohnOttCE(--nospam--at)]
> Reply To: 	seaint(--nospam--at)
> Sent: 	Monday, June 28, 1999 10:46 PM
> To: 	seaint(--nospam--at)
> Subject: 	Re: Field Observations - Stupid things I've seen
> Talking about stupid plumbers...........
> About ten years ago, we had designed an apartment building with underground 
> parking where the wood main beams spanned close to thirty feet. There was 
> plenty of height so the joists were shown to rest on the main beams. It was 
> anticipated that the plumbing waste lines would run between the floor joists 
> over the main beams and there was a special note on the plans calling for the 
> plumber to run the waste lines between the floor joists to a wall.
> Well, I got a frantic call from the builder one afternoon and was he beside 
> himself. The builder was a particularly good builder and always knew what was 
> good construction. He immediately realized a problem had developed. He had 
> gone to the lumber yard to pick up some hardware. During the time he was gone 
> the plumber, in his ultimate stupidity decided to not read the plans and to 
> run the waste line through the middle of the main beams at the center of the 
> span of the beams.
> Did this brain dead plumber drill a hole through the center. No! He took a 
> chain saw and cut a notch slightly deeper than the wood beam. Naturally the 
> builder was a little bit more than mildly concerned. He wanted to know what 
> to do.
> I told him to order a new beam, shore the building up, remove the damaged 
> beams and to install the new beams and backcharge the plumber. He did just 
> that! However I have always wondered if the plumber learned anything at all. 
> I have seen many plumbers on a job with a chain saw. I have always taken the 
> time to inform them that if they cut any framing it will be at their risk. I 
> sometimes think of the safety factors in the Code and wonder why they are so 
> high. After all airplanes are designed with a 5-10% safety factor. But when I 
> think of the plumbers (Electricians and H.V.A.C.) with chain saws I can see 
> that quality control is lacking for our industry.
> John Ott