Floor Joist bridging 1

[Dougjet]

I live in a house built in 1939. While doing plumbing repairs in the crawl space I noticed the cross bridging between my 2X12 floor joists is not, and has never been nailed to the bottom of the joists. (no nails, holes or splits in the 1X4's)
I understand that, in that era, the rough in guys would nail the tops of the bridging and after the load (rest of the house) was built someone would go back and nail the bottoms. Clearly this was not done.

While under there I noticed a whole lot of my insulation sagging and wanted to replace it. Here is the meat of it...

It would be a lot easier and more effective installing insulation without the cross bridging boards in the way.
Since the bridging has never been connected (78years now), should I just rip it down to make the insulation replacement easier. If its been this long without them connected, do I even need them at all. Surly the twisting and warping is complete by now. I have 1X6 diagonally laid subfloor and then 1/2" original oak hardwoods for all but the bathrooms.

Two of the larger rooms do have some bounce too them, but unbelievably no sagging in those rooms.
Only one small part of the entire 1st floor has some sagging. So a second question for the sagging area is... can I take and beam with shoring under each end in that area and over time take a few turns on it to raise that area back up?

My thought was to rip down the unconnected bridging to make installation of the insulation easier but in the rooms that have bounce nail the cross bridging in place. (if I can even nail into the petrified wood)
I have no idea whats right for the sagging area in a hallway near a bathroom.

Please give me your thoughts on this.

Thanks
Doug USN retired

 

[XR250]

After 78 years I think you can remove it. I believe the mentality with bridging back then is to nail it at the last moment possible to prevent squeaks.

 

[kipfoot]

I'd say to screw in the bottom of the bridging; it will help distribute point loads to adjacent joists.

A properly sized beam will significantly increase the strength and stiffness of the floor, but I'd be cautious trying to push the joists back to their original shape. Long term deflection in wood can create a permanent deformation.

Most importantly, I'd also suggest that before you replace the insulation be sure to read information on 'conditioned crawl spaces.'

 

[CANPRO]

Just another point of caution about jacking up your floor - if there were any renovations done over the last 78 years, things such as doors and plumbing may have been installed to suit the sag in the floor. I've seen old floors jacked up to flat and then none of the doors above it could swing. In one extreme case I saw, raising the floor to level dislodged some existing plumbing.

 

[Dougjet]

Thanks for the feedback. After what I’ve read I won’t be trying to jack the sag back up to full height. I’ll just shore it up so it won’t get worse.

Any thoughts about removing the unconnected bridging to get the insulation upgraded easier and then using strapping instead of putting bridging back in?

Thanks
Doug

 

[SLTA]

I've been in many an old house without the bridging you describe. I agree with XR250 - I'd say after all this time, it's no problem to take it out. Good luck.

Please remember: we're not all guys!

 

[EngineeringEric]

Going back with strapping would be fine. I think we all agree that bridging is not needed at this point and usually isn't needed structurally for your floor. it is needed for serviceability and stability.

Remove the never-connected 1x, add insulation, and then straps would be nice.

Old wood may be hard to nail and may be a bit more brittle than you think

 

[Dougjet]

Thanks everyone for the feedback.