The creation of engineered soils have created many new opportunities to amend and manage infield surfaces. One of the new opportunities is a 2 inch cap over an existing laser graded sub base. How can a 2 inch cap be successful? I thought infield mix has to be 4 inches or more in depth? Simply stated, engineered soils use the correct proportions of sand/silt/clay to allow for the cap. Think - a more engineered asphalt can be installed at a thinner depth than a gravel road. DO NOT attempt a cap if the material is not engineered.
Below is a review of a 2 inch cap installation at Hamilton Heights High School. This surface did not have infield mix added for the past 10 years, so it was 2 inches below finish grade.
Let’s go through the steps:
First step - Laser grade the existing infield mix to ensure the sub base is a consistent 2 inches below finish grade.
Laser grading the 1st base sub base as the first load of Dura Edge Classic is added to the laser graded 3 rd base sub base
Second step - Add 100 tons of Dura Edge Classic
Third step - Laser grade the Dura Edge Classic and compact with a static 3 ton duel drum roller
Laser grading new Dura Edge Classic cap
Fourth step - Topdress the Dura Edge Classic with 3 tons of Diamond Pro Professional Calcined Clay
Fifth and final step - Finish drag
This project was completed in one day. Keep in mind the long term maintenance cannot include any activity below 2 inches. This is not a problem with engineered soils. As a rule of thumb, less is more with engineered soils. Less maintenance, less nail dragging, less rainouts, etc. This surface will perform well and no additional infield mix will be needed for the next 3-5 years depending on maintenance, topdressing programs, etc.
Go to j-dturf.com to learn more about J&D Turf.