I recently wrote about almost accidentally overloading my basement slab with a huge pile of tile that we’re storing.

As the saying goes, “garbage in, gospel out” - I had made my calculations based on some faulty assumptions, which I fortunately caught before I went to the trouble of buying a shipping container and having it delivered for storage. Here are my calculations for posterity.

The tile we are storing comes in rectangular pieces that are 1’x2’. So two square feet. There are six pieces of tile in a box, which weighs about 46 pounds. Somehow I had gotten it into my head that there were only two pieces of tile in said box. Oops.

So, 46 pounds for 12 square feet. Assuming a worst case of 2200 square feet (we will have less than that), that’s 184 boxes of tile, or 8464 pounds to store.

But that doesn’t all go on shelving. We are storing 74 boxes directly on the floor, on edge, between the legs of the shelving. That’s 3404 pounds resting directly on the concrete over a 4x8 area. That should be fine. Heck, a king size water bed can be put upstairs; it weighs about a ton when the weight of the frame and headboard is added in.

That leaves 110 boxes for upper levels, or 5060 pounds. Divided by four, that’s 1265 pounds per leg; once the weight of the shelving itself and whatever camping gear we throw on the upper shelves is added we are probably looking at more like 1500 pounds per leg.

This is a far cry from 5000 pounds, and hardly worthy of concern by comparison, especially when one considers I already have plates under the feet to spread out the load a bit.

Plans for the garage and the shop are still to way overengineer the slab so that I don’t have to think about things like this anymore just in case i get something really cool to put in the garage (a tank doesn’t count since the tracks spread out the weight so that it’s lighter per square foot than a person). Hmmm, what will I put on my wish list?