Subgrade Preparation Essentials for Concrete DrivewaysThe subgrade should be compacted and have an even thickness. A standard driveway is 4" thickâyou want 4" thick continuously, not a 3" to 4" varying thickness. Many western states have expansive soils. In these conditions, from 2" to 8" of crushed rock should be used as subgrade material depending on the soils level of expansiveness. If you have doubts about the soil characteristics in your area, consult a soils engineer. Find a Concrete Driveways Contractor Find a Concrete Contractor 23 Services in 200 Metros -- U.S. and Canada © 2008 ConcreteNetwork.com None of this site may be reproduced without written permission |
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