Reinforce Subfloor for Safes

[Mathieu18]

Anyone have thoughts on reinforcing the subfloor for a couple safes (about 1000lbs empty)? It’s going in a 12x12 room roughly but obviously the ones under the safe are going to carry most of the dead load. Plan is to sister the joists underneath and maybe the girder(s) if needed. I know I need to see which way the joists are running, where the safes are going and if the plywood subfloor is stout but thought I’d get general thoughts on how beefy to make it. It’s old style construction, looks like 2x6 sitting on top of a 12” beam. Thoughts appreciated.

 

[Trevillian]

2x6 floor joists???

Regardless of that. Decide the known location of where you want the safe to sit. Then depending on crawlspace access. Pour footers for that area then reinforce the joists and add supports to those footers. Can be as strong as you like.

I'm an overkill is under rated type myself.

 

[Mathieu18]

2x6 floor joists???

Regardless of that. Decide the known location of where you want the safe to sit. Then depending on crawlspace access. Pour footers for that area then reinforce the joists and add supports to those footers. Can be as strong as you like.

I'm an overkill is under rated type myself.

Could be mistaken, I’ve only seen the inspection photos of the crawlspace, haven’t been down there yet. It was build mid 50’s though. Pouring footers and new piers sounds miserable, though I get your point…

 

[Leadchunker]

At minimum you could stack concrete blocks under the floor joist for support.

 

[Mitch Rapp]

I put a jack under my house with a piece of treated 4x4 run across the affected joists under the safe. Removed a few inches of dirt, used some leftover landscape pavers, a concrete block, and a scrap piece of 2x8 as a cap to make the 'footer' for the jack to stand on.
Working like a charm.

 

[Burt Gummer]

I put a jack under my house with a piece of treated 4x4 run across the affected joists under the safe. Removed a few inches of dirt, used some leftover landscape pavers, a concrete block, and a scrap piece of 2x8 as a cap to make the 'footer' for the jack to stand on.
Working like a charm.

This is the easiest way in my opinion, and works great. Dad did that under his house when he built it in several places. Under the gun safe, where the kitchen island is, under the whirlpool tub

 

[ronn47]

If you sister the joist also use construction adhesives and structural screws to tie the sisters together.
An extra beam in the middle, as noted above would be a good idea.

My house was built in '55 and has 2"x8" (true measurement) joist.
Yours prob does also unless that room was added later.

 

[Mathieu18]

This is the easiest way in my opinion, and works great. Dad did that under his house when he built it in several places. Under the gun safe, where the kitchen island is, under the whirlpool tub

Wouldn’t Jack Stands be a better long term solution?

Good thoughts and ideas though. Thought it might be true dimensional lumber. Good for the strength, annoying for all the notching… don’t hate laying a base and using a small screw Jack or block to make a non structural pier.

 

[Trevillian]

Could be mistaken, I’ve only seen the inspection photos of the crawlspace, haven’t been down there yet. It was build mid 50’s though. Pouring footers and new piers sounds miserable, though I get your point…

All good. It obviously works. Depending on soil composition. You can easily do as many mentioned above. Pavers, a pt 2x12, etc on a flat spot on the ground. Anything to spread around the weight you want to add. Then just ad extra framing and gtg.

I remember crawling into a sagging floor replacement job to start an estimate. The brick and stone fireplace was added who knows when. But they added river rock supports with wood shims under the true 2x8 original joists. It was the only spot in the whole house that was still stable.


I'm just the idiot who would put in the effort to build actual piers for me🤣

 

[Burt Gummer]

Wouldn’t Jack Stands be a better long term solution?

Good thoughts and ideas though. Thought it might be true dimensional lumber. Good for the strength, annoying for all the notching… don’t hate laying a base and using a small screw Jack or block to make a non structural pier.

A screw jack would work long as you had a good solid base under it. Dad built “stiff knees” as he called them. 2x6 boards fashioned in an I shape. None of them have sank, rotted, fell, or moved in 20 years.

 

[Carolinatlc]

I put a jack under my house with a piece of treated 4x4 run across the affected joists under the safe. Removed a few inches of dirt, used some leftover landscape pavers, a concrete block, and a scrap piece of 2x8 as a cap to make the 'footer' for the jack to stand on.
Working like a charm.

I did very similar under my house using a screw jack. Stuck the next safe in the garage since I didn't have any room left inside. I'm thinking about adding a smaller 12 gun safe I saw at costco up in a closet upstairs. It's only 250lbs so I'm not terribly concerned with reinforcing it.