Brickeye,

I have a bunch of questions for you regarding using #10 1.5 steel straping to stiffen floor joists... let me start by describing my sisters nitemare situation...ill try and keep it as short as possible!!! new construction...builder fired due to sloppy const. and after 18 months not complete.. the 1st floor is where the problems are..the great rm is 15'8"wide from block wall to I beam. all the joists are doug fir no2 2x10s 16"oc and their are 16 total. also no cross bracing!( actually there was but the plumber Bent them out of the way to run pex tubing) which is another problem !! he drilled the holes in the center of the span, two 2-1/2in holes 5/8in from the bottom of joists and 1in apart!!!! as you can imagine it feels like qodzilla is coming when some1 walks throu the room!! The master bedrm ,also on the first floor is 16'wide and 15'long ; 15' being the lenght of the 2x10s and are NOT incised. i fixed that room by sistering new 2x10s glued with PL prem and screwed with 2 1/2in exterior deck screws staggerd in a VV pattern and added blocking about every 4'10" before reading your method... also added a layer of 5/8in osb glued and screwed over the exsisting 3/4in osb which was left exposed to the weather for who knows how long!!! all the seems were swelled up and seems to be starting to delaminate!! i used a floor sander to knock the top layer off before laying down new subflr.. im very pleased with the result but alot of work !! due to the water& elec. drilled throu the other joists i didnot want to do it that way...i want to stiffen the rest of the 1st floor and wanted to know the actual number factor that each method will accomplish..also under the great rm there is hvac running along the wall, the strapping would have to stop 34in from wall to avoid remove&replace ducts ...acceptable??

1st- sistering new 2x10s = 2.0 double the stiffness( correct?)

2nd- adding 2x4 straping = 2.5 (???)

" 2x6 " = 2.7 (???)

3rd- adding no. 10 steel 1.5W = ?????

basicly i want to get the stiffest floor but considering i will need appox. 800ft to do rest of 1st flr. i want to compare price to stiffness factor 1st! sorry for such a long bunch of questions...thanx in advance

Scott Tessmer

Pittsburgh ,Pa