Excellent video, Tim! I have weak points in my flooring due to over-spanned joists and will be installing bridging to secure the floors. Thank you very much!
My house was built 2 years ago with I-beam floor joists. The span is 16' and it's a little bouncy. I installed 2 rows of X bridging spaced evenly after watching your video and notice a huge difference. Thanks.
Added cross strut to floor joist today, to replace one I took out, to add recess spot light underneath the original strut - now I fully understand what they do, and super glad I did not skip doing it
Hi. We have a 1960s house and we removed the first floor floorboards and saw that the cross bridging is barely touching the joists in some cases and is the cross bridges are not nailed to the joists. We have access only from the floor abone and not from level below. What can we do? Shold we try and screw them into the joists top and bottom however we can but just from the top (as we do not have access from below) Any advice?
We found mice had gotten into the Crawlspace due to previous owners not paying attention. We removed all the insulation when the crawlspace was encapsulated. This exposed the fact that the bozo's installing the batt insulation between my floor joists had disconnected the metal floor braces instead of cutting the batts to fit between them. What's the best way to return the structural integrity to the floor joists? Attempt to re-install the metal braces or install blocks?
I have I-joist for my subfloor and feel plenty of bounce and vibration in my house. Anything different cerning I joist vs dimensional lumber floor joist?
Hey Tim, during the installation of our HVAC system, they knocked out a bunch of cross bridges to get the round air duct in. There is no room now for a 2x10 or a new cross bridge to go in its place. Is there anything you can do? You might be able to fit a 2x4 under the air duct, but that's about it.
so if you have floor 20ft x 8ft, and joist are running along the longer side how you bridge them? you cross the underneath horizontally in contrast to what you draw @1:46 - vertically?
If the joists are 20 feet long you would need 2 sets of bridging no more than 8 feet apart. You can use cross or solid bridging. If subfloor is already in use solid bridging.
It should, if the duct work is in the way you could add blocking under the duct. If it is new construction you could ask the building inspector, codes vary by location.
I had foam insulation installed in my crawlspace, so almost impossible to install any bridging. Should I follow the 2x4 method and brace underneath the joists?
Did you use open or closed cell foam? The closed cell has some rigidity to it, open cell does not. Adding any bracing would help with bouncing or bowing floor.
@@timpalmer-logstolumber1999 It is closed cell foam, but does not completely fill the joist -- I never checked after they were done. So, do you think if the joists are completely filled there might not be any bounce?
It is usually recommended that you nail or screw through the board you are attaching into what you are attaching it to. If that is not accessible, attach as best you can.
(True below, speak up.) BUT, do not, not do this. Install the bridging like he said, nail on top and do not nail the bottom yet. install your sublfoor and any walls during the build. Once the Dead load is established and before the Live load begins, THEN nail the bottoms of the Bridging. therefore a load on a single joist is spread out two joists on BOTH sides of the load. Think piano leg. So in effect, five joists are carrying the piano leg. Forget solid bridging unless it is over a carrying beam or girder. And use construction glue under the subfloor on the joist. Pay attention to his spacing regarding the run. F--k the Draftsman that forgets these important details. If you are a heavy person and hear squeaks coming from the floor years later, well, now you know...
You are correct about the load being applied before nailing the bottom. As far as using solid bridging it comes to two things, codes and preference. Always check local building codes. And yes always use liquid nail when laying subfloor.
The crossed bridging will be stiffer, because you are basically making a truss structure, where the force is inline with the grain direction. The solid blocking carries a shear force, but you can still consider it equivalent to the x shaped path for tension and compression, but misaligned to the grain direction.
