IMO, contractor number 2 is overkill. 'Clay loam' is a pretty indistinct description and can cover a wide range of soils. Does the area drain well after a heavy rain or is there puddling? Have you ever done a perk test?

If your soil drains reasonably well then I think #1 with the permeable pavers will work perfecty well.

The first contractor did not quote a permeable installation, while the second contractor did quote a permeable installation as you requested. There in lies the difference in cost. Below is a routine cross-section of an "open grade" or permeable installation. Installation varies slightly from location to location but this is similar to what you might expect. Good luck.

Contractor #2 is the only one bidding a permeable paving job, as K&D mentioned. In my experience, a lot of people are interested in permeable paving right up until they see the numbers. Then they're ok with conventional pavers. We usually price for 12" of base; I assume the #2 stone layer is in part because of the clay soil at the base?

What was your reason for requesting permeable pavers? Does the proposal include a means of exit for excess water (like the pipe shown in K&D's cross section)? And are you comfortable with the long term maintenance needs of a permeable installation? Over time, dirt and debris and other stuff blows in and settles in the joints, clogging the #8 stone and turning your permeable pavers into impermeable ones.

If you're not wedded to permeable, I'd ask contractor #2 to requote it that way. I think you'll see the cost delta shrink way down. Contractor #1 concerns me just in that they either just slapped a permeable paver over a traditional base, or else they ignored the request altogether.

@DG. Please note @Revolutionary Gardens closing comment which is noteworthy, "Contractor #1 concerns me just in that they either just slapped a permeable paver over a traditional base, or else they ignored the request altogether." Your patio is something that you want to enjoy for a long, long time. Selecting the right contractor is everything. Again, good luck.

Thanks for your comments. We installed a permeable paver patio at a prior home and loved the fact that it drained well. On this property, the soil tested as red clay from 6" to about 56" down. Our septic drain field lines are 78" deep.

Neither contractor liked the idea of permeable pavers. Seemed to us, the larger stone would give better void space for water to eventually drain into the clay. However, we were concerned that was not sufficient. We had asked about a drain; both contractors said it was not necessary.

Thanks for the input. At this point, not sure what we will do.

Thanks for adding a follow up.

Very impressive DG. Not too many folks can say they tested the end result with two very major named storms in in the same season and ended up with no standing water. Congrats!