Hey guys I know you need to slope your patio for water run off but how do you do it ? Lets say I need a total of 2.5 inches of slope when I dig out the whole area to a depth of 7 inches on the sloped end to I dig out 9.5 inches and than add my 4 inches of base all around ? I'm confused how to slope it and how your plan / mark out for the slope any help would be great thanks
Typically, I would start with a stake at each corner; outside of the actual corner enough that they won't be in the way. Make a pencil mark for finish grade on the stake at what will be the or a low corner, then use a transit, dumpy level, laser, or line level to mark the remaining corners, based on the slope that you want, typically in the 1/8" to 1/4" per foot range. Now's a good time to check the relationship of each mark to the surrounding soil, and make sure that it is what you want. Then you can use a line (string) from any of the marks to another, laterally, diagonally, whatever you need, along with a 4' level, to excavate consistant with the slope of the patio. Once you have the base sloped, you can essentially the same procedure to bring your gravel to the desired elevation. If you wish, you can also use the lines between stakes, along with your level, to set some small stakes throughout the excavated area, at the level the gravel will come to. Use small stakes, not too deep, so that you can easily pull them once the gravel is in place, and align the top of the gravel with the top of the stakes.