I want to remove about 250 square feet of grass/topsoil and then lightly grade for drainage below a future deck.
Should I:
- Man up with a spade & a rake?
- Rent a sod cutter & go deep?
- Use some tool I'm not aware of but you're about to explain?
It depends on whether you want to keep the sod or no and if the ground is already pretty flat. I haven't used a sod cutter, but I think the ground has to be fairly level. I don't think it works well if there are dips in the ground.
I think for 250sq/ft, which is around 16'x16', you can man up with a shovel and a pickmatic. Figure out where you want to have your graded area and put stakes at all 4 corners. You can get cheap bamboo stakes from the garden center, it just has to be able to hold some light tension.
Take some cheap string and tie it to one corner on the high end of the grade. Wrap it a couple of times so it doesn't slip and take it to the stake, on the same side, at the bottom of the grade. By on the same side I mean the two furthest from the house or closest to the house. So, high and low on the outside and high and low on the inside. Use a line level: http://www.harborfreight.com/3-in-line-level-67765.html
to make sure the line is level (get it? line level.). Then give it a couple of wraps to prevent slipping and tie it off. You need to know your grade you want. For instance, if you want a 2% grade, that would be 1:50 or 1" drop for every 50". At 16' on one side of your 250sq/ft area, that would be ~3.84" of drop. Let's round it to 4" for easy figuring. Tie a new piece of string from the same point at the high end and 4" lower at the bottom of the grade.
More than likely you won't be able to, because your ground will be fairly flat. You'll have to go ahead and start using your shovel to dig a sloped trench till you can pull the line tight and it clears the ground. Repeat this on the other side and then you can use a piece of line stretched between them to check your grade. You can tie a slip knot or however you want so it slips, but it needs to be tight enough not to sag in the middle and give you a false read.
It's simple, though. You dig and scrap where the line touches and fill in when there is gap under it. When it cleanly goes from the top to the bottom and just barely makes it over the ground, you've got your grade in that area. Good luck.