FLAGSTONE & PAVER PATIOS
You must prepare your area making sure that you have dug deep enough to accommodate all of your materials so that the very top will be at the wanted height.
Make sure that when you walk out of a door onto your patio that the patio will be lower than the bottom of your door or door sill. This ensures that when it rains you will not have water running into your door.
For base, use a minimum of 4 inches of 3/4" crusher run limestone. This material has a powder to it and will compact and turn hard almost like concrete.
After laying the base you must either use a vibratory tamper or a hand tamper.
After this has been compacted, you will add limestone screenings (also known as 1/4" down limestone) at a depth of 2 inches. It is best to add and level your screenings as you are working backwards laying your flagstone or pavers. You need NOT compact the screenings, just start laying your material. Make sure you use a Level when laying each piece, not only to level each piece but to level piece to piece.
When you are using flagstone, the limestone screenings may be used for the gaps.
When you are using pavers, there are many varieties of sand that you can use over the top to be swept into the joints. Some may work better than others.
After the job is completed, water down till wet and let set. Mist do NOT use a hard spray.
MAN MADE BLOCK RETAINING WALL
For a wall 3 foot high you should use a 65 pound block. The higher the wall the heavier the block that should be used. Retailers of the block should have charts.
You must prepare your area so that the first row of block will be under the lowest level of ground around it. Depending on the grade of your area you may end up burying more than one block.
For base, use a minimum of 6 inches of 3/4" crusher run limestone. Compact this material with either a vibratory tamper or a hand tamper.
Lay your first row of block with a mixture of portland and gravel mix on top of your base.
Make sure that each and every block is level, laying the block on top of the portland and gravel mix.
After laying the first row, let set up before laying the rest of the wall.
Before back filling your wall.
On the inside of the wall at the bottom you should lay a 4 inch socked perforated pipe the length of the wall to a low point or to an opening in the wall (pictured below).
If not using perforated pipe, weep holes should be made into the wall so that any excess water behind the wall can drain.
This is your last step.
Back fill the wall with 1 1/2" Clean limestone (Engineers have switched to this product from using the 3/4" Gravel) 12 inches thick or wide behind the wall to just under the cap stone.
Note : If doing sod at the top of the wall, you will need 12 inches of topsoil under it (keep this in mind when back filling) and may need to be watered frequently.
Don't hesitate to ask, there are no "dumb" questions.
If we can not provide you with the information, we can hopefully refer you to someone that can answer your questions.