We're in the process of building a gravel driveway that's about 750 feet long as the first phase of our home construction in Pennsylvania. Our excavator, along with others I've consulted, suggests that if it were their house, they would excavate the topsoil and lay down 4 inches of AASHTO #1 (also known as PA #4 or Ballast, which is about 3.5 inches of clean crushed rock) followed by 4 inches of 2A limestone. However, our civil engineer has specified 6 inches of 2A limestone and isn't fond of having the large rocks at the bottom. He believes that the smaller 2A limestone will wash into the larger stones over time unless we include geofabric between the two layers. So, I'm weighing my options: 1) stick to the engineer's plan with 6 inches of 2A, 2) add the #1 layer for an extra $2000, or 3) add both the #1 stones and geofabric for an additional $4000. What do you all think? I'm leaning towards the first option and using the savings to pave part of the driveway later on if we encounter issues.
3 Answers
Honestly, I’d go with leaving the #1 stones in during construction. With all the heavy traffic and potential rain, it’s going to need that solid base. You can always top it off with the 2A once everything's settled!
It really depends on the type of ground under the topsoil. For example, if you have clay or something rocky, that could change the game. I get that engineers have their calculations, but a seasoned excavator with a solid reputation likely knows what makes a great base from experience. Just something to think about!
One crucial piece of advice: make sure you have as much paved driveway space as possible near the house, especially in front of the garage. It really helps with keeping the mud and dirt at bay!
For sure, we plan to pour concrete in that area, but we’ll have to hold off until the house is built and we’ve moved in.
The soil report says it’s very gravelly silty clay loam, so I get where you're coming from!