Expert: Dan Griffin - 12/27/2007

Question
I'm in the process of having a new home designed for my wife and I.  We love the out doors so the home plans we're working on include a large covered deck (10 x 35) angling to a 13x16 partly covered, partly open deck then a 16x19 screen porch.  All of this area is above a walk out basement.  In an effort to minimize the number of columns or posts needed to support it all, plus the fact that all of the support needed also supports the roof of the home that covers it all, my designer specifies using steel beams and steel posts.  Naturally, the posts run from ground to ground to roof (which also has steel beams supporting it).  

My question is what is the best way to attach the deck framing materials to the steel beams so that traditional joists can be used to construct the deck.

Also, what is the best way to create a decent looking finished product underneath it all.  Ie: covering the beams and posts.

And Finally, since this is all outside in the elements, is there anything I need to do to avoid rust, mold, etc. to the steel or materials attached to it?

Thanks

Answer
The top of the steel columns should have lumber shoes installed.  Here is an example:  look at the CCO type shoe shown at the bottom of this page: http://www.strongtie.com/products/connectors/CC.html
The steel structural drawings should show something similar welded to the tops of the columns.

Paint is minimal for exterior metals.  If the metal can dry out without holding moisture things are better for the wood and the metal both.  Galvanizing is more expensive, but would be well worth while in the long haul.

I assume you don't like the look of exposed steel columns.  They can be hidden inside fiberglass or wood false columns.  They can also be cased in rock or brick to match the house if appropriate.   I still think it would be more valuable to not cover everything so that sunlight and wind can help keep things dried out and help prevent mold conditions, if you intend to have a deck through which water can migrate.