Question: I've got a "crawl space" (really an unfinished space) under the main floor in a 2-story-with-basement house. I'd like to build essentially a deck frame and cover it in 3/4" plywood so that we can more easily use it as a storage area.

Picture of the space:
[![Posts on the left, foundation not visible on right](https://i.stack.imgur.com/Kr09Z.jpg)](https://i.stack.imgur.com/Kr09Z.jpg)

I've been planning on attaching a band joist to the concrete foundation on the right side, and additional band joists attached to the support posts on the other side (left side of the picture). I'd then run floor joists between them (approx. 7.5' in length) supported by joist hangers.

Is attaching to the support posts a bad idea? Not being a structural engineer, I worry about the additional load, and the potential for weakening those posts by attaching the band joists with lag bolts. Should I be worried, or is there a better way to support that side of the floor that doesn't involve digging down and pouring concrete footings?

Answer: 
Concrete pigments are available. But for what I think you are wanting, you would start by grinding/sanding the block smooth, then painting it (black) with an epoxy base coat, then sprinkling it with decorative metallic/colored flakes (the loose fines are cleaned off), and then a clear epoxy top coat is layed over it. 

Here's a youtube video for this procedure (on a garage floor): <https://www.youtube.com/watch?v=YjEI1P9vtGg>. 

Extra steps to ensure a longer life for the concrete? 

I would probably use either waterproof additive or waterproof concrete (with premixed additive). And I would definitely opt for the UV resistant epoxy.

I might also consider using a silane or siloxane (impregnating) based grout sealer for pre-sealing the concrete (which might not be worth the cost- I'm not sure; since you are covering it with epoxy anyway). But to estimate, lets say a quart costs $20, and it will basically cover 100 square ft, (or 10 headstones)... I might be tempted to do it because it might help if the concrete starts to crack or chip after a while. Good (silane or siloxane) grout sealers tend to hold up for 1 to 3 decades, so for the price, I might do it... but honestly, I don't know if it would help.
[![[1]: https://i.stack.imgur.com/4UVhV.jpg](https://i.stack.imgur.com/8ybSE.jpg)](https://i.stack.imgur.com/8ybSE.jpg)

I have found that using an inexpensive plastic container as a mold works quite well. Use painter's tape where writing and numbers will be and glue them to the tape, then trim the tape with razor knife close to the writing. (remember writing mus be backwards!) I prefer the fiberglass type concrete to the quickrete (rock and sand) type used for the two you see here. Use the quality concrete colorant and mix it very well before adding to the concrete. Take your time working all the air bubbles out without disturbing the foam letters and numbers. Set mold at proper angle and let dry for 20-30 days.