Is this good enough for support??

[Jeff000]

Originally Posted by gregzz4

I was going to do the same as you when I had my 125g
A builder aquaintance suggested a 1/4" steel plate of 6x6" or larger under the jack post
The wood you have under it may split and could be a bit larger to prevent the concrete from cracking (it is a concrete floor, ya?)

I also talked to an engineer. Because of the cost of liability I didn't pay him for his services. He told me he entered my flooring and weight specs into his formula and told me that, if I were to pay him, he would suggest the above idea as a minimum, but because I wasn't paying him, he wouldn't be legally allowed to tell me that

The rest looks great. All I'd add to it is some cross bracing between the new support joists to prevent twisting

Doesn't make sense, a 1/4" 6*6 steel plate would be just as or less effective than the wood he has under.

[Myka]

What's under the jack posts? Concrete slab? If there are no footings poured under the jack posts the jack posts will probably crack the slab. When that happens the shift could cause failure. I've seen pictures of such failures.

[sphelps]

Yeah point loading slab = bad. That's why structural engineers cringe but it'll probably be fine if that helps as it's really not that much weight. Personally would have build a wall in place of the beam and shimed it up tight under the joists to distribute the load.

[Myka]

Originally Posted by sphelps

Personally would have build a wall in place of the beam and shimed it up tight under the joists to distribute the load.

That's a good idea. You could build yourself a little "load bearing" closet right there.

[AquaticFinatic]

So I should just build another wall instead of the posts? From what I can find out the floor is at least 4" thick plus. I know I should have run joists and maybe tripled up but to much wiring and plumbing in the way for that.

[Myka]

Originally Posted by AquaticFinatic

So I should just build another wall instead of the posts? From what I can find out the floor is at least 4" thick plus. I know I should have run joists and maybe tripled up but to much wiring and plumbing in the way for that.

That is typical slab thickness. The best thing you could do would be to jackhammer that slab out where you want the jack posts and pour a footing under it then hide the jack posts in a wall or something. I imagine you're not keen on that though. The length of a wall spreads the point load of the jack posts provided your bottom plate in the wall is at least doubled to help spread the weight instead of just bending. If you were really concerned, you could build a lintel (like over a window) made with a couple 2x10s to lay on the floor to spread the weight. That won't bend.

[gregzz4]

Just an example of spreading out a load



Figure 7. Bearing pressure on a shallow foundation.

The suggested idea of building a closet is a great plan. Build a load-bearing wall and enclose it to create a storage area. Then the area is not wasted by a jack post

[gregzz4]

Originally Posted by Myka

The best thing you could do would be to jackhammer that slab out where you want the jack posts and pour a footing under it then hide the jack posts in a wall or something

This is, of course, the best solution
Then build a storage room around it

[gregzz4]

Originally Posted by Jeff000

Doesn't make sense, a 1/4" 6*6 steel plate would be just as or less effective than the wood he has under.

How would it be less effective ? We're talking about point loading here
Steve and Myka pretty much covered what I was pointing out
Point loading the concrete floor will break it
By placing a larger foot of something that won't break under the load, you're spreading the weight out over a larger area, thus putting less stress on a smaller area of the concrete
And ya, the wood he has there under the post will collapse under load
Have you ever hammered any soft wood ? It compresses very easily
His wood will compress and/or split