The 9 1/2" ijoists I am using are rated for a 16' 8" span for L/480 deflection..
The house spans about 28 feet in width. In the back part of the house I ran the ijoists accross the house and there is a middle wall supporting the ijoist midspan.. That section of the house is fine as far as boucing.
However the front part of the house there is one room accross the whole 28' feet. This room is abot 14' deep. In this section of the house I ran my i josts front to back from the front of the house to a steel renforced LVL. This area bouces.. When looking at it from below it is not the beams that are bouncing but the ijoists itself.
I think this might be why, I started applying subfloor in the back of the house with the plwood going front to back (accross the joists).. However for the last 14' I continued running the plywood front to back (with the joists). In that area I have the bounce. Does running the plywood with the ijoists contribute to floor bounce? Everything is laid out correctly such that all my long plywood seams split the ijoists. Everything is glued and the crap was nailed out of it.
Is the direction of the plywood the major factor here?
I have three possible soltions
-Renforce both sides the I joist on both sides with rim board to make them stiffer. This is what is shown in GPs manual as a way to renforce cantilevers so should be helpful
-Add blocking at the mid point. I think this might be helpful as the ijoist seems to roll slightly as it starts to sag plus tieing them together will distribute the load somewhat.
-Add new i-joists in between these making the ijoists 8' on center at that point.
- Add filler block and anohter i joists (double them up).
Any recomendations? I dont like the idea of going 8" on center as that will make hard for highats.
Adding blocking is cheaper then renforcing but if I need to reinforce the ijoist after adding the blocking I will end up ripping the blocking back out. So maybe add the rim board to both sides of ijoists first and if that doesnt cut it I can then add blocking to that?
Was not changing my plywood direction when the joists changed direction my problem here?
gp manual is here(page 23 of 56 shows the method I was thinking)
http://www.gp.com/build/product.aspx?pid=1390
The house spans about 28 feet in width. In the back part of the house I ran the ijoists accross the house and there is a middle wall supporting the ijoist midspan.. That section of the house is fine as far as boucing.
However the front part of the house there is one room accross the whole 28' feet. This room is abot 14' deep. In this section of the house I ran my i josts front to back from the front of the house to a steel renforced LVL. This area bouces.. When looking at it from below it is not the beams that are bouncing but the ijoists itself.
I think this might be why, I started applying subfloor in the back of the house with the plwood going front to back (accross the joists).. However for the last 14' I continued running the plywood front to back (with the joists). In that area I have the bounce. Does running the plywood with the ijoists contribute to floor bounce? Everything is laid out correctly such that all my long plywood seams split the ijoists. Everything is glued and the crap was nailed out of it.
Is the direction of the plywood the major factor here?
I have three possible soltions
-Renforce both sides the I joist on both sides with rim board to make them stiffer. This is what is shown in GPs manual as a way to renforce cantilevers so should be helpful
-Add blocking at the mid point. I think this might be helpful as the ijoist seems to roll slightly as it starts to sag plus tieing them together will distribute the load somewhat.
-Add new i-joists in between these making the ijoists 8' on center at that point.
- Add filler block and anohter i joists (double them up).
Any recomendations? I dont like the idea of going 8" on center as that will make hard for highats.
Adding blocking is cheaper then renforcing but if I need to reinforce the ijoist after adding the blocking I will end up ripping the blocking back out. So maybe add the rim board to both sides of ijoists first and if that doesnt cut it I can then add blocking to that?
Was not changing my plywood direction when the joists changed direction my problem here?
gp manual is here(page 23 of 56 shows the method I was thinking)
http://www.gp.com/build/product.aspx?pid=1390