Replies

1. 
   Piffin | Mar 16, 2003 06:13pm | #1

   I think you've been doing it right, according to all the old basic standards and that he is doing a very sloppy job of his engineeering, based on nothing more than assumptions.

   One of the basic principles of structural design is that load paths must always drive directly to the foundation. Anytime there is deviation from this model, each situation must be individdually analysed and planned with calculations performed to be sure that loads will be supported adequately.

   I have a few rules of thumb that work for me and occasionallyu do light engineering or have the LVL and floor truss suppliers do it for me. For more ticklish engineering, I always hire someone qualified to tackle it.

   Your buddy is doing his customers and future homeowners a dis-service. I am betting that he builds in an area with no building inspectors. If you have respect for your self, and concern for your future reputation based on quality and integrity, you will ignore his advice and example. You could possibly even make a pretty decent living following him and fixing his homes for the new owners when they discover all the things that crack or no longer fit.

   and Welcome to Breaktime. It's home to Fine Professionals in many walks of life.

   "Fine" is an attitude to espouse.

   .

   Excellence is its own reward!

2. 
   GHR | Mar 16, 2003 11:00pm | #2

   By my math his joists will support 110#/sq ft (1/480 deflection) and his girders will support 1000#/lineal foot. About all that might be bad is that the subfloor might fail before the joists do.

   My math is very conservative.

   7' seems to be the wrong spacing. I would expect 8'.

   I got the room built. How do I get outside?
1. 
   Piffin | Mar 17, 2003 03:18am | #3

   That math is for the average spread out live and dead load.

   Now calculate what he has landing on those joist when a bearing wall lands halfway along at 3.5' and there is a 14' section of upstairs flooring and the center of a roof supported to the same line. Then suppose there is an arched openning transferring the load from a six foot span in that wall to two points wherer jacks land that just happens to coincide with no support to foundation beneath.

   .

   Excellence is its own reward!

3. 
   ScottMatson | Mar 17, 2003 04:08am | #4

   The other thing is he's filling up the basement with posts, unless it's a crawlspace, in which case I couldn't care less myself.

4. 
   Ward | Mar 17, 2003 04:47am | #5

   I agree with you and Piffin.  You always want a dead load transferred vertically to a foundation. 

   Even if you have trusses that support themselves and the roof load without requiring an interior wall, the load from that interior wall itself will be sufficient to cause sheetrock to crack and doors not to fit.

   In addition, would the seven foot oc theory have a beam beneath the joist overlaps? 

   Keep up the quality work.

5. 
   BossHog | Mar 17, 2003 03:56pm | #6

   " the only load an interior wall bears is roof bracing, right? "

   Stick framed roofs, or trusses?

   Makes a lot of difference.

   I wish you'd keep my hands to yourself.

1. 
   dangray | Mar 17, 2003 05:17pm | #7

   Stick frame roof. Now that I've gotten a few responses in favor of piers and beams under load bearing walls I totally agree, especially if you ever decide to convert any upstairs to living space, putting even more load on these walls. And someone brought up what about large cased openings in walls putting a lot of concentrated weight on each end. I'm no engineer but I really enjoy trying to figure the best way to build a house. Thanks for your response.