What does it cost to install interlock?

That is probably one of the most frequently asked questions in our industry. Let’s break it down with a hypothetical 100 sqft patio (10ft by 10ft).

There are 4 main costs:

  1. Materials (i.e. Stone, disposal, polymeric sand Weed Barrier, Base system, Infill, etc.)
  2. Labor
  3. Company Overhead (i.e Workers Comp, Gen. Liability Insurance, Advertising, Gen. Office Expenses, etc.)
  4. Company Profit
  1. Materials

  • Disposal: For a 100 sq feet patio you would have 4 cubic yards of waste for 10 inches deep. You would need 1-2 bins depending on how much waste needs to be disposed of. Bin- The standard price for a 4-yard bin is on average $275. In our case, we would need 2 bins ( the number of bins will vary depending on the amount of earth that needs to be removed) 275*2= $550.
  • Weed Barrier- You want to use an above-average weed barrier since the last thing you want is for weeds to be popping through your newly installed patio. In this scenario, it would cost around $100. 
  • ¾ Crush run stone – used for a solid base.100 sq feet * the depth of 9 inches = 2.7 cubic yards needed. $70 * 3 cubic = $210 + $100 for delivery.
  • Polymeric sand – used to brush between the cracks and seal your interlock. 7 bags * $40 = $280
  • Stone- The price will vary depending on the stone you choose. It could be anywhere from $5 per square foot to $25/square foot. For this scenario, let’s go with a mid-range stone at $11/square. $11 * 100 sq ft (+10% error)= $1210 
  • Edging, nails, extra materials for damages-You’ll need to use edging to create the barriers and shape for your patio. You’ll also have to consider the damage to the yard that will need to be fixed or update like sod or soil. $200
  1. Labor 

  • This is where the biggest price difference occurs. The cost of materials should vary very little across companies. However, when it comes to labor the price difference can be quite significant. When it comes to labor the difference between a seasoned crew with 100 installations under their belt or 10 installations is quite apparent. If you want a job done properly the first time around and it to last this is not an area to try and save a few dollars. The cost for a seasoned crew could be around $150-200/hour depending on how many crew members and where you live. For this project, say it take 25 hours to install * $175/hour = $4375.
  1. Company Overhead

  • Let’s look at some of these costs: General Liability Insurance, Licensing Fees, Corporation Fees, Payroll Expenses, Accounting Fees, Business Taxes, Lawyer Fees, Advertising/Marketing Expenses, Administrative Staffing Fees, Auto/Truck Expenses, Company Phones, Website, Hosting Fees, Internet, Computers, Camera, Credit Card Processing System, Office Rent, Yard Expense, Electricity, General Supplies (tape measure, landscaping paint, etc.). Let’s take 10% as an estimate for these fixed costs.
  1. Company Profit


Everyone needs to make a profit. Profits are what is leftover from the day to day operations to allow us to grow the business to make investments in future projects. Profits also allow us to offer our extended warranty on our service. 

The final math: 

  1. Materials- $2650
  2. Labor- $4375
  3. Overhead- $702.50

Total= $7727.50


10%- Total cost is $8500.25
15%- Total cost is $8886.63
20%- Total cost is $9273.00
30%- Total cost is $10,045.75

I hope this sheds some light on what a proper installation of an interlock patio, pathway or driveway. Of course, these numbers will vary between different contractors, but gives you a good idea of what’s involved in getting your stonework started. 

Next Steps…

If you’d like to discuss a project you have in mind, please get in touch to book a consultation with Inka Stoneworks. Book a consultation