Is Tar still applied underneath dimple board?
The short answer is yes it is.
The longer answer is that dimple board is not a waterproofing without anything behind it. Tar is NOT a waterproofing, tar is a damp proofing and should not be relied on to keep your foundation dry. Tar will try out in time leaving your foundation unprotected. Tar is also not that productive against area's that have a high degree of water in their soil.
You should be putting on a waterproofing product instead of tar. Then you install the dimple board over the waterproofing to protect the waterproofing from rocks, roots or any other debris that is in the soil when you back fill it.
There are many different types of waterproofing products, the most effective ones are the spray on membranes that have flexibility in them so that if anything was to move or shift the waterproofing wouldn't be ripped or compromised.
You should find a company that will install a spray on membrane, the cost is more but the product is far superior then tar.
Village Builders Inc.