Cross bracing floor joists

Runs With Scissors

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Evil, I installed all my own tile and flooring 23 years ago. It was a new build but we have the 1x2 cross bracing.

Anyhow, I was warned (by old school tile guys) that the only proper way to lay tile is to pour a leveling type cement and lay the tile over that, or it will crack.

I said B.S..........I've seen plenty of cracked tiles after doing it old school.

I decided to use DensShield by Georia Pacific.

It cuts just like drywall using a razor knife and is a breeze to install.

I think they suggest a screw every 6 or 8 inchs so I rented a stand up style, belt fed, screw gun from Home Depot and it took 1 or 2 days to put in all the screws in my entire house ( ~10,000+ screws if I remember correctly).

I have no crack or squeaks anywhere in my house.

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The Evil Twin

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Excellent information from you folks! I appreciate it. Good points all around.
Screws. Definitely screws no matter what. Even though I would rather turn the nail gun to full auto and BRRRRRTTT through it. Structural or decking. Both have a very low tendency to split wood due to the tip design.
Notching- even if wiring isn't in a good spot, I might be able to move it a little with some slack so that will work. I do remember that the water lines are secured halfway up the joist where they run parallel. Those can be X'd or something like that.
False wall- might add that in the form of storage shelves under the longest span. It would look intentional and left in place for selling.
As a note, one of their neighbors has the exact same model. I spoke to them in passing. They said they finished the basement in a basic configuration BECAUSE of the floor movement. The smart contractor told them they could do cross bracing but the same money would be better spent to finish the basement. Especially since they were considering doing so anyway. No need to do both. Not telling the parents that because I do not want to finish their basement. 🤣
Thanks folks.
 

GreensvilleJay

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curious as to the size( 2x10@16" ??) and unsupported span of the floor joists.
sub floor 'should' have been glued and screwed, that's code now here...

I'd sure hate to put $10K of tile down and months later see cracks.........
 

The Evil Twin

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curious as to the size( 2x10@16" ??) and unsupported span of the floor joists.
sub floor 'should' have been glued and screwed, that's code now here...

I'd sure hate to put $10K of tile down and months later see cracks.........
2x12 southern pine @ 16 OC. Longest unsupported span is <20' . It is glued n screwed (I can see where they have missed) T&G OSB subfloor. Code here does not require screws.
Getting new flooring is the exact reason we are doing this. Don't want to throw good money after bad.
 

GreensvilleJay

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hmm, 20' span seems too long for my 'gut'.
I'd be adding a 'support partition'. While 'down the middle' would be best, giving 10' wide rooms,you could go 12 + 8,depending on total length of basement and where 'mechanicals' are located.
Here, to clear span 24' we need 18" tall TJIs at 12"OC
 

GeoHorn

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Doesn’t “in intelligent”….mean “un intelligent”…?? 😜
 
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North Idaho Wolfman

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False wall- might add that in the form of storage shelves under the longest span. It would look intentional and left in place for selling.
That sounds like an excellent choice.
If you do that first and it eliminates the issue, saves you a lot of time and money!
 
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North Idaho Wolfman

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curious as to the size( 2x10@16" ??) and unsupported span of the floor joists.
sub floor 'should' have been glued and screwed, that's code now here...

I'd sure hate to put $10K of tile down and months later see cracks.........
LVP (Luxury Vinyl Plank) won't crack if the floor moves, as it's a floating floor. ;)
 

GrizBota

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That sounds like an excellent choice.
If you do that first and it eliminates the issue, saves you a lot of time and money!
1/2 the span, 1/8th the deflection. Or so says the math.
 
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The Evil Twin

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hmm, 20' span seems too long for my 'gut'.
I'd be adding a 'support partition'. While 'down the middle' would be best, giving 10' wide rooms,you could go 12 + 8,depending on total length of basement and where 'mechanicals' are located.
Here, to clear span 24' we need 18" tall TJIs at 12"OC
It's less than 20. Well within code here. Just don't remember how much less. I'm basing that on rough exterior dimensions that I remember from laying river rock along the perimeter.
 

North Idaho Wolfman

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True, but the kitchen tile is going to be a sizeable area. And most of the cost 😄
Oops, :oops: missed the tile end of this job, so yes movement not good!
I have 2800sf Of LVP to put down here if I can ever get a work break.
 
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