Thanks alot for supplying this help online. My question is regarding compacting dirt. My installation requires me to dig down 11' with a backhoe with it being a 4' by 4' square. In the middle of this hole there will be a 10" i.d. pvc pipe with a 3/4" id galvanized water pipe in the middle of it. The deep hole and the 10" pvc pipe prevent the 3/4" water pipe from freezing. When I backfill all the dirt in the hole I have to provide a 5' by 5' concrete foundation with bolts in the concrete to hold down a horse waterer. The foundation is to support this horse waterer and the galvanized pipe is connected to the existing well waterline. I think you can picture what I have. I was wondering what the best way would be to compact the dirt inorder to pour the 5' by 5' concrete foundation. I am concerned about the dirt settling over time and ruining the concrete. Thanks. :cool: MIKE

I want to pour a 8'x8' square concrete slab to place a home spa on. The spot I want to locate the slab on is sloped ground, maybe 5-10 degrees or so. The spa is rated at just over 4000 lbs wet, plus whatever people are in it. Once the spa is in place I will build decking around it to provide easy access. I've looked at the DIY Building a Foundation article that describes building a foundation for a garage. Looks to me like I could adapt this for what I need, by pouring the four footing walls in a box formation, the sides tapered so the highest wall is at the lowest point on the slope, and all four sides level at the top. Then I could fill in the cavity with gravel, and pour the slab with appropriate reinforcement and according to local codes. Having no experience with concrete other than setting fence posts with redi-mix, but being generally a handy DIY'er, is this a project I might tackle myself, or would I really be better off just getting a professional to do it? Appreciate any feedback. Thanks!