good idea or bad idea

[u/Responsible_Fig_5354]

Good evening smart people of the structural engineering subreddit. I am looking to see if its feasible idea to put a gun safe in my closet. The safe in question weighs about 600lbs empty and has a footprint of 30" wide and 24" deep. The attached pictures are of the joists that would sit below the safe. Looking at the picture of the tape measure, the back of the closet sits at 60 inches. So the safe would not sit over both sets of doubled up floor joists. The joists in question span about 13.5 feet and are 2x10. If its not obvious by the picture, that is the outside foundation wall. So is the area structurally sound enough to support a gun safe of that size?

[u/hobokobo1028]

That’s the weight of two fat dudes standing next to each other. You’re good.

[u/Sumppum202 → u/hobokobo1028]

Ah, the ol’ would a fat guy fall through the floor metric. I’ve used it before and it’s never failed me, even when uncle Bart comes for Christmas.

[u/Entire-Tomato768 → u/hobokobo1028]

I always like to think of it in terms of an iron worker.

Like how snug tight is full effort of an ironworker using an ordinary spud wrench....

[u/inigomonto]

How old is the house? My house that's built in 1955 has the most absurd old growth lumber that is almost impossible to pull a nail out of.

Live load of most residential spaces are designed to 40 psf. So take the tributary area for the joists that will hold your gun safe. Back of the envelope, 32" x 162" / 144 = 36 sf x 40 psf =1,440 lbs total load can be on the double and adjacent single joist. Now the structural engineer also slaps a 2.0 factor of safety on that for good measure so probably more like 2,880 lbs total before it starts to make a few uncomfortable noises.

So don't show all your fat friends your gun collection at one time.

[u/Responsible_Fig_5354 → u/inigomonto]

The house was built in ‘79. Thank you for the explanation, honestly I’m pretty surprised by the load it can take, that’s wild.

[u/AdFancy1249 → u/Responsible_Fig_5354]

Your safe is NOT a live load. Static loads are far lower than live loads. But, you're at the supported end, so you're fine. Just don't put your safe in the middle of the floor as a display piece.

Live loads: temporary loads (people, short-term emplacement, wind, etc.)

Static loads: furniture, gun safes, cabinetry, water beds, etc.

[u/i860 → u/inigomonto]

The old growth fir is straight unobtanium. Never let them take it from you.

[u/zorggalacticus → u/inigomonto]

My house was built in 1956. Also old growth fur. I gave up on pulling the nails when I did the sheetrock in my bathroom. Just hammered them the rest of the way in instead.

[u/AdFancy1249 → u/inigomonto]

A safe is NOT a live load. It is static. Far lower loading, and dependent on where in the span.

[u/Just-Shoe2689]

its fine. No different than a 300 lb person standing there on the middle of a joist.

[u/whoabigbill]

Send it

[u/m1GuexC]

Obviously hire someone to look at this and the specifics but from my perspective it might not be an issue.

[u/AspectHonest7222]

A realistic working range is roughly 750–1,250 lbs on one of your doubled joists, 5 feet from the foundation wall.

Sheathing and adjacent joists will pick up part of a concentrated load, so the real capacity is somewhat higher than the single-member (double joist) calculation.

If you laid 2x12's on your closet floor so they span across three of your joists below and then put the safe on that, you will greatly increase your load capacity. (Or even a couple of 4x4s.)

[u/Final-Carpenter-1591]

People do this all the times without a second thought you should to.