Replies

1. 
   Guest_ | Jan 12, 1999 03:31am | #1

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   What exactly is an ICF house ?

   Floor trusses that long will probably have a bit of "bounce" in them.How much is impossible to determine. You're wasting your money setting them 16" o.c. Set them 2' o.c. or 19.2" o.c., if local codes permit it. This won't affect the "bounce" much, and it will leave a lot more space for mechanicals.

   If you're using lightweight concrete for your radiant heat system, the trusses need to be designed for the additional load.

   Make sure you give the truss company the correct location and size of your stair opening(s). This is a major source of problems.

   Best of luck with your house.....

2. 
   Don_ | Jan 12, 1999 05:02am | #2

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   Ron.

   I agree with your statement that spacing the trusses further apart allows more space for mechanicals. Spacing the trusses further apart may require the trusses to be taller. Trusses are an engineered floor system and installing them in a way other than the manufacturer's requirements is courting disaster.

1. 
   Greg_Nugent | Jan 12, 1999 05:46am | #3

   *Neal,I have a related issue with TJIs in another thread here in breaktime. The issue is effective blocking for things like toiltes, bathtubs, parallel partition walls that fall between trusses. It is very easy to do blocking with standard 2x lumber but not with TJIs and I suspect not with open-chord trusses.

3. 
   Guest_ | Jan 14, 1999 08:27pm | #4

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   Neal,
   In 73 or 74 one of the first houses in the area with floor trusses,30 foot span clear span basement,open floor plan above. If I recall right aprox 24 X 30 great room , built to code ,The damn room bounced like spring board , end up building wall in basement ,it helped , I think code is L/360,I you want clear span basement ,open floor plan up ,build floor Over Code !!!

1. 
   Guest_ | Jan 16, 1999 06:58pm | #5

   *Don - you're correct in being concerned over what I said about increasing the spacing of the floor trusses. But, for experience, I know that 24" deep floor trusses can span about 34'. The truss company I work for won't build them at a clear span of over 32', however. We can make them look good on paper, but they "bounce" too much.

4. 
   Don_ | Jan 16, 1999 08:20pm | #6

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   Ron,

   I am with you on the thought that these trusses will be bouncy. Also I am aware that many of these systems may be "over engineered" and you can get away with doing something else. My concern is that we live in a society with a lawsuit mentality. When you don't follow a products installation guides exactly, guess what? their multi million $ tail is off the hook and yours is on. Just read the papers and talk to enough builders, this is a scary business.

5. 
   Neal_Hoaglund | Jan 16, 1999 08:20pm | #7

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   I will be building an ICF house (2 levels) in the spring & will be using 32' floor trusses with radiant heat system. Because the depth of the trusses will be 24" (16" centers), I was wondering if there are any pitfalls I should look out for.