Originally Posted by Fremont Dave
Here's an update:
The girders (4x6) run the width of the house, are attached to the foundation on each end and are supported by post/piers at 60" intervals. Each girder is spread 48" (OC) from its neighbor. Currently, there are no joists running between the girders.
Amazingly, my house is built in nearly the same fashion with the exception that the beams in my house are 4X12. This can't possibly be any form of standard construction, especially for a house built in late 1970, such as mine.
I have a three substantial dips in the subfloor between beams as of now. The worst offender is a 1.5" drop in the floor directly beneath the water heater. In my case, I'm planning to replace a piece of water damaged 1-1/8" subfloor directly beneath the water heater with an identical 1-1/8 patch supported from beneath by 2X6 joists spanning the 4' OC distance between beams.
Did I mention that I have no idea what I'm doing? Would you believe that this project started out last month as an attempt to replace an old Federal Pacific load center that had caught on fire? This home repair stuff snowballs entirely too well, doesn't it?
Anyway... I was thinking that adding in the 2X6 joists was the right way to go about fixing existing half-witted construction. While I'm at it, I could even insulate the floor. What a concept!
Someone feel free to steer me in the right direction if I'm going about this all wrong.