My bro-in-law is planning on building an addition to his house. His site slopes down from the front to the rear of the house. It's going on the back of the house where there is foundation exposed - about 7'.
It's possibly gonna be phased as far as enclosing the new addition, but the extreme final condition would be a 2 level space - Family room on the lower level and additional bedrooms on the upper level. We just need to build the foundation system to accomodate the heaviest load.
We're planning on putting the new floor on lally columns on concrete pad footings. The addition will be 25'x30' (with the 30' dim going out from the existing house).
My question is three-fold:
1. Is it better to run the girder parallel or perpendicular to the existing house?
2. In either case (parallel/perpendicular), do we need to install lally columns alongside the house (about 1'-2' away from the existing) or would the girder(s) just attach to the exiting floor joist system and the first row of lally columns start 15' from the house (at the midspan of the addition)? I'm concerned about the closeness to the existing foundation wall footings...
3. What's the typical girder dimension for a built up girder spanning, I guess, 15' since there will be columns at midspan...??
Last edited by JeroldLopez; 08-27-2009 at 10:51 PM.
Since this is for a residence, you will need a building permit. Since they will want plans, you'll need some engineering drawings. Best to start there since I doubt anyone here can give you anything more than somewhat generic advice and that really isn't what you want when building structure for habitation. My 2 cents.