Step #2: Location, size, and calculations for your pavers. Calculate how much of each material you need based on your patio’s dimensions.
Mark your desired paver location to visualize its size and calculate materials needed. Use a turf spray paint to mark the outline of your patio. This will greatly help for not only visualization, but also for a digging boundary.
Here is a picture of the finished patio outlined above (before cleaning).
Paint a Perfect Circle in proposed location
Think about whether you want curved edges or 90 degree corners. To paint a circular mark, drive a wooden stake where you would like your circle’s center to be located. Cut a piece of string to size matching the desired radius length (plus a bit more for tying slack). Tie one end of string to the stake and your spray paint can to the other. Stretch the string out to use like a compass. Walk the circle while keeping the string tight and simultaneously spraying the paint. Now you have a perfect circle! Or maybe you only want a circular curve (i.e. part of a circle). Determine the location of where you would like your curve. Choose a larger radius for a wider curve and vice-versa. There are also methods of drawing (constructing) perfect ellipses, rectangles, squares. For more info on constructing, click here.
Quick Guide for Shapes and their unique properties:
- Circles – The distance from the center of the circle to all points that lie on the circle are equal.
- Rectangles – Their diagonals always measure exactly the same
- Square – A square is a specific type of rectangle. A square’s 4 sides all measure exactly the same (in addition to having equal diagonals).
You’ve chosen your location and size of your paver patio, now for the important calculations.
click the picture below to enlarge
Sketch out your patio design to scale. It will bring to life the location, size, and calculations needed for your paver patio. This particular sketch was drawn using Dynascape software.
Other sketches:
paver driveway and walkway (above)
flagstone patios (above)
Area or Size
Calculate the area of your space first. Try to look at your space in terms of a rectangle: length and width. This works best when your patio shape is not any one specific shape. You’ll recall that to the find area of a rectangle, you need to multiply the length by the width. Say your future patio location is a circle with radius 10 feet. Sketch out that circle, and then draw a rectangle on top of it. You have a rectangle with length 20 feet and width 20 feet. So the area of that rectangle is 400 square feet which isn’t too bad of an approximation of the actual area. But it’s not awesome either. Recall that the area of a circle is 3.14 x radius x radius, which equals about 314 square feet. Of course using the actual formula is going to get you closer to the actual size dimensions. However, a lot of the time the planned paver space is just an irregular shape that is no one single shape. In those cases it is good to just approximate the calculation by sketching in a rectangle on top of it. Always figure in an additional 5-10% on your calculated square feet to adjust for cuts. So if your paver space measures about 314 feet, then order between 330 sq ft and 345 sq feet.
Why square footage?
Why calculate square footage? First, pavers are usually priced per square feet. The paver manufacturer packs the materials in pallet form for bulk transport. Most of the time, pallets are between 100 and 150 square feet. So going back to our earlier example, a paver patio with space 314 feet. We would want to order about 340 sq feet. Say this specific paver comes in 115 square foot pallets. Then you would want to order 3 full pallets (115 x 3 = 345 sq ft). A lot of places you’ll order pavers from will allow you to order portions of a pallet, usually called layers. The downside of ordering a partial pallet is they will many times charge an extra “break pallet” fee.
Second, square footage helps determine the amount of aggregate needed (ABC, c-33 sand, fabric).
ABC Calculations
You are going to want 6 inches of an ABC base. Sites like Better Homes and Gardens say 2 inches. That’s ludicrous. With only 2 inches of ABC your patio will fail in a year or two. If you’re going to be driving on it (i.e. driveway), go with 12 inches. But building your pavers on 6 inches of ABC is plenty for a walkway or patio. More than that would be overkill. With less than 6 inches, however, you could run into problems. ABC is usually sold in cubic yards or tons. Let’s figure out how to calculate the number of cubic yards of ABC you will need. We can always convert cubic yards to tons if that’s how they measure it in your area. Some landscape material supply stores weigh your material before loading your truck (tons). Some will load your truck with a cubic yard size bucket. Take the square footage (in square feet), multiply by the depth (in feet), and divide by 27. For instance, for a 314 square foot (SF) patio: 314 x (6″ / 12″) is equal to 157. Notice that 6″ / 12″ represents your depth in feet (1/2 of a foot). Then take your 157 and divide by 27 which equals about 5.8 cubic yards. In a nutshell:
cubic yards ABC = (SF x depth) / 27 = (314 x 0.5) / 27 = 157 / 27 = 5.8 cubic yards
Just remember that the depth of your ABC will always be 1/2 (since 6″ / 12″ is 1/2).
C-33 Sand Calculations
As you will see in a later step, you will be screeding 1″ of sand; no more, no less. Since you only need 1″ of c-33 sand, the quickest way to calculate is to just divide your ABC cubic yard amount by 6! 5.8 / 6 = about 1 cubic yard of sand
cubic yards of sand = (cubic yards ABC) / 6 = 5.8 / 6 = 0.97 or about 1
Cubic Yards to Tons
If the landscape materials supply store near you prices by the ton, all you have to do is the following:
tons of sand/ABC = 1.5 x cubic yards sand/ABC
Woven landscape fabric calculations based on size
Look at the box of woven fabric to calculate the square footage of fabric per box. Purchase accordingly. Make sure to purchase enough sod staples as well to fasten the fabric to the ground. For instance, a 4 foot by 50 foot roll of fabric will cover 200 square feet of area. Since we will need to slightly overlap the seams, two full rolls (400 square feet) should be plenty. Purchase enough sod staples to space them out 3 feet from each other in both directions.
Conclusion – importance of locations, size, and calculations – be precise!
In summary, you need to make some calculations after deciding where you want the patio. ABC and C-33 sand are the biggies. Yes, you do have other minor calculations such as: bags of polymeric sand and linear feet of paver edge restraints. Your patio size (area and perimeter) will determine the amounts of these. We’ll go into more detail about such items later on in the installation step.
There is no better feeling than ending up with just the right material amounts after the project is finished. Want to be annoyed? Order way too many pavers only to have to restack them back into the truck to return them. Or finish the patio and then have a huge pile of ABC left in your backyard. After finishing your project you want to be enjoying your end product, not shoveling more product! Performing the correct calculations will ensure that you end up with just the right material amounts.