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meature 02-26-2011 02:44 PM

Bridging--bouncy vibrating floor
We have a new home and the floor vibrates and has some bounce. It is hard to distinguish between the two. It is iritating and does give the home a high quality feel.
(Our builder went bust, lots of problems, but not for this post).

36ft span, with 2x4 supporting wall at midpoint.
LPI 20 plus i-joists 11 7/8, flange is 2 3/8. 16" oc.
Open from below.

Obviously I wish the floor was supported with LVL beams and posts, but I don't (didn't) know anything. I don't believe it is a significant structural problem, more something that iritates me and does not feel high quality. Probably within code but on the low end.

What solutions would you recommend?
1) I am giving serious consideration to bridging. Would this make a noticeable difference? I have stumbled on the this product called IBS 2000 Connectors by Luxocorp. Anyone familiar with it, would it be better than something I get from local lumber yard or big box? It is more expensive.

Do I need to do something more dramatice and expensive--beams and posts? strapping?

Basement is unfinished.


fungku 02-26-2011 04:01 PM

bridging/blocking and strapping would help. Whatever kind you use you will notice a difference. What you want to spend is up to you.

Blocking is probably the easiest to do now that it is probably a finished floor above, but not so easy if you have wires and mechanical running parallel with the joists....

I'm sure there is a product out there that makes bridging from below easy, I just don't know what so maybe someone will come in and save the day here.

loneframer 02-26-2011 04:17 PM

6 Attachment(s)
I joists that are not rocked on the bottom should have strapping every 8', minimum.

I prefer wood X-bridging. I joists with LVL flanges should not be nailed through the sides. I have had good results with 7/16 crown staples for this application.

I did an experiment one time to show how X-bridging helps to unify the floor, forcing several joists to share a concentrated load. In the test, there is nothing supporting the weight, other than bridging.
Here's a link to the thread

and here's a few pics...

meature 02-28-2011 09:44 AM

Bridging floor
FungKu and Loneframer, thank you for the replies.

Sounds like bridging is the way to go, I hope it makes a difference.

If anyone has familiarity with the IBS 2000 Connectors, please chime in?
Also, if anyone wants to offer testimonals on bridging, did it provide noticable help on floor vibration?

Loneframer, I had seen you pictures when I was searching the forum for some background information--pretty cool.

fungku 02-28-2011 03:29 PM

for "vibrations"... i don't know, but yes bridging will generally stiffen your floor noticeably.

loneframer 03-02-2011 06:17 PM

Properly installed bridging and/or strapping will make the floor feel more solid. (Less deflection, less vibration)

To me, bridging is something worth doing and I always recommend it when I'm framing, even when it's not required.

gallen12 10-24-2012 02:33 PM

Ibs2000 floor bridging
Luxor Wood Products is the manufacturer of the IBS2000 floor bridging. If you have any questions or would like more information on our product please contact me, Glen Allen 1-877-496-4355 or

oh'mike 10-24-2012 03:57 PM


Originally Posted by gallen12 (Post 1037157)
Luxor Wood Products is the manufacturer of the IBS2000 floor bridging. If you have any questions or would like more information on our product please contact me, Glen Allen 1-877-496-4355 or

Glen--thank you for joining us---The manufacturer is the final answer when someone is building-----Mike----

gallen12 10-24-2012 03:59 PM

If we can be of any assistance please give us a call. We are here to help. Thanks Mike

lylsutherland 10-30-2012 03:42 PM

mid span bridging
Mid span bridging
As I read through the different threads regarding mid span blocking/bridging,I find many different views on what part blocking/bridging plays in a floor system ,so I thought I should put my 2 cents in.

Full depth bridging has traditionally been used for long-span dimensional lumber as a load sharing device, because vibration in a floor has been a problem for at least four decades.Floor vibration is not a structural problem with any type of joist you use in a floor.As we use lighter Engineered I-Joists in light residential construction, bounce and vibration is more prone to be a problem.

Bridging/Blocking plays a very significant part of a floor system,just like sub floor thickness and adhesives, strapping or direct applied drywall, depth and O.C joist spacing or the series of I-Joist used in a floor.

I-Joist manufacturers don't recommend any form of mid span blocking,but they do say it can help with floor performance. They tell you to use a deeper joist, closer o.c. spacing or a more expensive joist to get a better performing floor which in turn increases the L/over and decreases the deflection to help limit the bounce and vibrations in floors which occur in longer spans.They started at L/360 then L/480 and are now recommending using up to L/960 to help address bounce and vibration in their floors and by doing so, you add more mass and cost to the floor. Deeper I-Joists,deeper flush beams,deeper hangers,deeper rim board,more siding, more money for your floor system.

As we change the parameters of a floor you achieve longer spans .I.E. glued floor versus unglued floor,strapping versus no strapping. All floors are limited to a L/360 deflection, which in long spans could deflect up to 1/2" or more and give you a trampoline effect in the floor or vibrate when you walk across the floor.The floor can deflect an inch or more and it don't have any problems until somebody walks on the floor

Historically, designers have used Uniform Live Loads Deflection to predict floor performance. Designers and builders tell us that the performance results using uniform load criteria are not consistent. Uniform live loads never occur in floor systems so the concept of using non-existent conditions to measure the acceptability of floors is neither practical nor accurate.The acceptability of floors is determined by more factors than deflection. Velocity of travel,acceleration,duration of vibration and frequency of movement all contribute to the dynamics of a floor's performance.

The proper measurement of performance requires a good tool and proper calibration. For floor's, the best performance measurement system combines the point load response of a floor to footsteps with a floor performance rating system. Uniform live load is not the service condition that causes floor performance problems. The acceptability of a floor is determined by its response to a person walking on it.These impact loads create the annoying bounce and vibration problems in floor systems.

A Load Sharing Connector improves floor performance by structurally connecting the floor joists together which forces the floor to act as an integrated system,thereby gaining stiffness and rigidity. Load sharing design offers new alternatives in floor design that can address the common problems of soft,bouncy floors and by sharing impact loads you reduce the annoying effect of bounce and vibration in your floor. With a systems approach,you transfer impact point loads such as those generated by foot traffic to as many as eleven joists.

Bridging/blocking requires an effective means of connection and must be installed prior to any loads imposed on the floor. With this connection, the proprietary bridging is faced nailed through the wide plywood uprights to the joist flange so when the sub floor is put down,the bridging is put in a tension mode,which starts the load sharing capabilities. When the bridging is placed in a row,it's like having a flush beam within the floor. Testing has been done with nailing the flanges of an I-Joist to a effective proprietary bridging product using 2-7d common nails on the top flange and 3-7d nails on the bottom flange.

tony.g 10-30-2012 05:36 PM

This seems familiar!:laughing:

GBrackins 10-30-2012 05:49 PM

like deja vu all over again .... :whistling2:

tony.g 10-30-2012 06:07 PM

[quote=GBrackins;1041271 deja vu all over again .... :whistling2:[/quote]

That one always makes me smile; I'm sure I first heard it as a kid, spoken by Yogi Bear as he was talking to Boo Boo.:laughing:

lylsutherland 10-30-2012 06:28 PM

I ran your LPI 20 11 7/8@16 o.c. and assuming a glued and nailed subfloor with no strapping through our floor performance program and I came up with a floor performance rating of only 69. By adding 1 row of IBS2000 at mid span,we can increase the floor performance to 106 or 2 rows at 1/3 points would be 122 and twin rows 1' off of center would increase the floor performance to 133. I hope this will help in your decision on what to do.

GBrackins 10-30-2012 06:35 PM

not sure, but the OP was almost about a year and half ago ....

tony, yes one has to be smarter than the average bear

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