floor bounce

[cuda70gt]

I have used this site a few times in the past and you guys really know your stuff, so here I go again with a new question.

I want to remove all bounce out of the floor above which is a kitchen.
I have a room that is 15 feet 4 inches long and 12 feet wide, its all open with no dry wall.

The ceiling/ floor joists are all single 2 x 10 spanning the whole 15 foot room and 3 of the 4 walls are 2 x 6 studs except the exterior wall which is 2 x 4 construction with a window and a door. and the floor is 4 x 8 ,5/8 plywood. there are no posts in the middle of the room and I want to keep it open concept.
this is all unfinished original construction built by the original builder.

the floor above is a little bouncy, you walk across it to hard or to fast and the fridge moves back and forth and anything on the table shakes.

the ceiling /floor was built with no bracing in between the joists so I have added 4 rows of haring bone ( x cross bracing) in hopes of stiffening the floor. there are also 2 air ducts running in between two separate joists.
I had to use a 2 x 6 screwed across the bottom with triangular shaped pieces screwed to the joists in order to continue the bracing all the way across.

the bracing is now complete, problem is the floor still seems bouncy, I guess I was expecting the floor to be rock solid with all the bracing in place but I can still get the fridge to sway easily.

should I have used different braces ??
should I have doubled up the 2 x 10 joists??

cuda70gt

[MJ CORMIER]

I would have went with 5/8 chip board, ripped to fit the exsiting 2x6, then applied a run of 2x6 over that.
MJ

[Fischer]

I've had good luck gluing and screwing in a layer of plywood on both sides of bouncy joists or trusses. I've staggered the joints in the plywood on opposite sides. The higher the number of plys, the stiffer the floor. Never tried OSB.

The nice thing about plywood, is that it's easier to install than dimension lumber in this situation, and every bit as stiff if not stiffer.

[cuda70gt]

thanks but I don't think the 2 x 6 studs are issue, I think the issue is with the 2 x 10 joists and the bracing but I may be wrong.

cuda70gt

[cuda70gt]

fischer
let me see if I understand.

so you are saying, I should cut pieces of plywood into 3 foot by 9 inch strips and glue/ screw them to the side of the the 2 x 10 joists.
and do this along all the joists for the full 15 foot length.
is this correct??

cuda70gt

[Fischer]

fischer
let me see if I understand.

so you are saying, I should cut pieces of plywood into 3 foot by 9 inch strips and glue/ screw them to the side of the the 2 x 10 joists.
and do this along all the joists for the full 15 foot length.
is this correct??

cuda70gt

No, you would cut them 8' x 9". The long length of plywood (8') is stronger than the shorter width (4'). Other than that and staggering the joints you're correct. I would start the first piece at a full 8' longon one side, and then the other side the first piece would be at 4'long.

[cuda70gt]

ok, i get it, I should use a full 8' on one side of a 2 x 10, then start the other side 4' down so that 2 piece of plywood never have 2 joints never start at the same point.

this will mean removing the haring bone bracing and then reinstalling the bracing once the plywood is in, plus removing and replacing the electrical as well.....lots of work!!

ok, I will do it!!
I guess I had better get started .

thanks for the input.
this site rocks!!

cuda70gt

[Fischer]

You don't necessarily have to remove electrical. That's the beauty of using plywood. If you figure it right you can run a joint on 1 side of the beam next to the wire, and then on the other side just make a slit. When you screw and glue you won't really be sacrificing much in the way of rigidity. The glue makes the whole thing kind of monolithic. Not much difference than the theory behind glue lams.

You will have to take out the herring bone bracing though.

[cuda70gt]

oh I get it, joint or notch around the wires, thank you Fischer, I was not looking forward to pulling all that wire.

I will take out and the reinstall the herring bones as I go.

I will use 6 ply 3/4 plywood glued with PL premium and 2" screws should hold it in place.

thanks fischer, this is awsome advice!!


cuda70gt

[Fischer]

oh I get it, joint or notch around the wires, thank you Fischer, I was not looking forward to pulling all that wire.

I will take out and the reinstall the herring bones as I go.

I will use 6 ply 3/4 plywood glued with PL premium and 2" screws should hold it in place.

thanks fischer, this is awsome advice!!


cuda70gt

3/4" might be a little overkill, but it would be solid. 5/8" would suffice. Otherwise looks good.

[cuda70gt]

here is an update...
I have been working hard to install all the plywood as Fischer suggested.
it is all done and wow!! what a difference, the floor above is solid as a rock.
I had an assistant walk :creep:on the floor above as I watched for movement, there was no motion at all :ridinghorse:
thank you for all the help guys!!
this site rocks!!

[Fischer]

Very Cool. There's no shortcuts to doing a job the right way. Congrats.