I am currently getting bids for paving my gravel drive. I have a question about thickness, lifts and compacting.

When I requested proposals I asked for bids to do two lifts of 2 inch thickness, compacted to 3". Two contractors gave me a quote for that but the third said that 2" lifts are difficult. He initially proposed a 3" lift rolled to 2". When I said I didn't want that he said he could do two lifts at 2.5" but that made the job twice as difficult and he upped his 2" price of $16K to $30K for the two lifts.. Any idea why the huge difference in cost?
Is there a rule of thumb for estimated final thickness based on pre rolled thickness?

I initially wanted a finished drive rolled to 4" thick. Is that thickness unnecessary? Is a 3" thickness adequate for a residential driveway?

Also there was a significant difference in the area of my proposed drive. I walked it with all 3 contractors using measuring wheels and their results 3600 s/f, 3750 s/f and the last was 4240 s/f. Is it unusual for that much variance (measurement #3) or is this guy padding the area?

 

Are you sure you typed those prices in correctly? Seems very high. $30,000?
Have you considered concrete? I know that in my area concrete is way cheaper than blacktop. A reversal from years ago.
I would confront the estimators with the variance in measurements. Get out your tape rule and do your own calculations.
I made 8 planter boxes this week and brought one to the nearby nursery who sells stone. I want to fill the boxes with #2 stone as stabilizing weights for my free standing gazebo. He see's the box and says it's equivalent to a 5 gal bucket. It looks like it. But my calculations say it maybe 3/4 vol if that much.
Point being, do your own calculations and let them know you're only paying for what is correct. It would be interesting to see how the high guy squirms (assuming his measuring wheel in incorrect).

 

Norm - I did my own measurements. The 3600 s/f is pretty close to what I expected. And the money numbers are right. I did some research before asking for bids and found that in our area the typical driveway is laid in one lift, rolled to 2" or less! I wanted something more than that.

The $30K was a drop from his original quote on site. He first said $42,000 and when I told him that was a no go he came back with a written contract price of $30,000. So I have 3 bids $15,000, $17,000 and $30,000 all for 4" of asphalt in 2 lifts rolled to 3".

 

Geez, I paid $3,000 for a 1,500 ft² driveway, though it was admittedly almost 20 years ago. I do recall it was 4" rolled to 3". I lived there eight years and it was pretty good except for one maybe two foot long spot on one edge where weeds would try to grow through.

 

Everything I can find on the internet on asphalt trade sites says that 3"-4" of asphalt is minimum for a residential driveway. I now have 5 bids all in the $14K - $15K range but they all want to lay 2" - 2.5" after compacting. One of the proposals is from a very well respected company that has a good rep.

My question is - do I really need 3"- 4"

 

I think 2" or so of asphalt is the norm around here but that doesn't include the 4"-6" of slate/gravel they compacted under the pavement.