On the topic of being a pseudo engineer, I agree that the libility can be severe if one takes it upon themselves to "engineer" a portion or all of a project without the appropriate credentials.
Not withstanding, it is important to know where to get the best engineering possible. Go to the manufacturer to get the best possible data on questions and/or products that present a solution to an engineering problem at hand.
With that in mind, engineered floor and roof joists are becoming the replacement for dimensional wood products.
The question of "holes" and where can they be cut is not frivolous. The structural integrity of a floor or roof can be destroyed with the inappropriate installation of air ducts, plumbing and electrical lines.
I have found the folowing information re: holes, on page 24 and 25 of the JAGER US Residential manual very informative.
http://www.jagerbuildingsystems.com/pdfs/guides/USA/us_residential.pdf For the ultimate flexability the "Space Joist" design with open web integral with an upper and lower Chord is the best system that I have found to date. There is a premium to pay for the joist but when the trades are considered, the overall capital costs are lower.
For anyone interested, JAGER also provide software to assist the project manager or residential contractor test various products and their design capabilities. I have had great success in knowing what I want before I contact the truss manufaturer. Good to be aware of the alternates for competitive quotations as well.
Doug.....et al (who is this al anyway?)
[This message has been edited by DGT (edited 01-16-2004).]
