[gramps416]

re: replace asphalt driveway. best method??

Hello,
I have an asphalt driveway (approx 900 sq ft) that needs to be removed and replaced. the 10 feet closest to the garage does not have a 2% slope. It is flat, and there is a downspout in that area, so rainwater stays too close to the foundation. I am also going to replace the adjoining walkway.

From a bit of DIY investigation through using a 12" spike at the edge of the driveway and some digging, I have determined that there are (2) 2" layers of asphalt on top of about 5 to 5 1/2" of crushed gravel or stone. This driveway (or at least the top layer) has been in place for at least 25 years.

The asphalt itself for the most part is in good condition, but there are some issues (photos included).

1. There is too much material (asphalt or gravel underneath) at the top of the driveway to achieve proper slope, and the garage concrete floor is just a tad higher than the asphalt. This would rule out the possibility of adding an extra layer of asphalt on top of what's already there to try and achieve a slope.

2. there are a few long troughs or ditches at the top 10 feet of the driveway, where the tires of a car have pushed it down over the years. i put a straightedge perpendicular to the trenches and found out the worst areas are 2 1/4" lower than the surrounding asphalt. some are less. (see pics)

After having a couple of contractors inspect them, i am told that because the asphalt has not crumbled over many years, that the base is in good condition. They mentioned that they would remove the asphalt, regrade the existing gravel to achieve a uniform slope, let it air out for a few weeks, add extra gravel compact and 2" of new asphalt.

I wanted to know if the contractor's procedure sounded like a good idea (will it work properly?)

Is it a waste of money to remove the existing gravel? (and replace with new)?

I also wanted to widen the driveway by about 2 feet, but I am concerned that there will be settlement where the rest of the driveway is already settled leading to the asphalt cracking over time. Is it ok to widen? or leave the width the above procedure.

 

[Ron6519]

The gravel base was inadequate, that's why you have the troughs.
Could be, not enough gravel, the wrong type gravel, not compacted properly, etc.
As long as the contractor addresses the base issue, you shouldn't have a problem widening the driveway.
Ron

 

[gramps416]

The gravel base was inadequate, that's why you have the troughs.
Could be, not enough gravel, the wrong type gravel, not compacted properly, etc.

how should the base issue be addressed?

1. after removing the asphalt, should they move the gravel to a pile temporarily, and then remove some dirt to allow for a thicker base?

2. can the existing gravel be reused or must it be replaced with new limestone? (or reused crushed concrete)

 

[Ron6519]

how should the base issue be addressed?

1. after removing the asphalt, should they move the gravel to a pile temporarily, and then remove some dirt to allow for a thicker base?

2. can the existing gravel be reused or must it be replaced with new limestone? (or reused crushed concrete)

You would need to find out the reason the driveway failed(ruts) Someone knowledgeable of the current situation and in the business who saw the sight and did the digging would be the best source.
A driveway engineered for residential vehicles should not fail as yours did.
The aforementioned 2" of asphalt seems a bit paltry.
Did they mention "keyed" sides where the asphalt is thicker at the edges so it doesn't roll up towards the middle?
I'd research online "asphalt driveway construction" and compare what you read to what the contractors are suggesting.
Ron

 

[gramps416]

You would need to find out the reason the driveway failed(ruts) Someone knowledgeable of the current situation and in the business who saw the sight and did the digging would be the best source.

I am in this forum to display the symptoms of the problem for an appropriate solution. I have done my research and provided as much information as possible to aid in the diagnostic. Frankly I don't trust even the two most reputable contractors in my area, which i contacted because they seemed to think this was a simple solution. I disagree, it is not simple.

Only measured at the side of the driveway becuase I didn't want to tear up the centre. It could be thinner in the centre or it could be the same, but I don't really know.

The aforementioned 2" of asphalt seems a bit paltry.

From the research I have read, even in cold climates, the condition of the base is far more important than the thickness of the asphalt. In fact, my inquiry is almost entirely a question of how that base it to be constructed.

so is the contractors suggestion reasonable?

can they reuse the gravel and have it function properly.?

if the old gravel can be reused, should they create a temporary pile and regrade the earth underneath or regrade just the gravel?

Is this type of failure normal if the driveway is over 15 or 25 years old? (it is something like that) You can see the aggregate showing through on the surface when you look close enough.

 

[Ron6519]

Go to the link below and read what it sats about how an asphalt driveway should be constructed.
According to this, the gravel base you have is inadequate.
All this information is a click away.
Ron

http://www.askthebuilder.com/NH025_-_A_Strong_Asphalt_Driveway.shtml

 

[gramps416]

I don't mean to be rude, you information is helpful, but please give someone else a chance to respond as well. Different perspectives are useful, and I have a unique situation that is not entirely covered under Tim Carter's article. I am familiar with Tim Carter and his site, a very useful resource. I like his in depth look at gutter guards. Also his videos on how to properly grout is top notch

 

[jomama45]

Hello,
I have an asphalt driveway (approx 900 sq ft) that needs to be removed and replaced. the 10 feet closest to the garage does not have a 2% slope. It is flat, and there is a downspout in that area, so rainwater stays too close to the foundation. I am also going to replace the adjoining walkway.

From a bit of DIY investigation through using a 12" spike at the edge of the driveway and some digging, I have determined that there are (2) 2" layers of asphalt on top of about 5 to 5 1/2" of crushed gravel or stone. This driveway (or at least the top layer) has been in place for at least 25 years.

The asphalt itself for the most part is in good condition, but there are some issues (photos included).

1. There is too much material (asphalt or gravel underneath) at the top of the driveway to achieve proper slope, and the garage concrete floor is just a tad higher than the asphalt. This would rule out the possibility of adding an extra layer of asphalt on top of what's already there to try and achieve a slope.

2. there are a few long troughs or ditches at the top 10 feet of the driveway, where the tires of a car have pushed it down over the years. i put a straightedge perpendicular to the trenches and found out the worst areas are 2 1/4" lower than the surrounding asphalt. some are less. (see pics)

After having a couple of contractors inspect them, i am told that because the asphalt has not crumbled over many years, that the base is in good condition. They mentioned that they would remove the asphalt, regrade the existing gravel to achieve a uniform slope, let it air out for a few weeks, add extra gravel compact and 2" of new asphalt.

I wanted to know if the contractor's procedure sounded like a good idea (will it work properly?)

Is it a waste of money to remove the existing gravel? (and replace with new)?

I also wanted to widen the driveway by about 2 feet, but I am concerned that there will be settlement where the rest of the driveway is already settled leading to the asphalt cracking over time. Is it ok to widen? or leave the width the above procedure.

BUYER BEWARE:

These guys have no idea what the subgrade consists of until they take up the driveway. As a concrete contractor, I come across these situations all the time. I ALWAYS provide an allowance in my proposals for remediation of the gravel base for a job that looks like this. I can almost guarantee you that the existing gravel directly around the ruts and most raked areas, as well as where any water lays, has been infiltrated with large amounts of soil & dirt. The reason they would wait to reinstall asphalt is because they know that it will be extremely soft under these areas, and if it's wet, there's no way they'll be able to compact the areas adequately. The soil will be far too mushy to do so. I'd move on to another contractor who wants to do it correctly, which would be to pull up the gravel, stockpile on site, under-cut the soil sub-base, and re-install the gravel along with whatever additional gravel is needed. If that's done, there's no reason the entire driveway can't have at least 2% pitch to it.

Have you considered getting a bid for a concrete driveway, considering you'll have a contractor there already with ready-mixed concrete for the sidewalk? It may not be as much of a cost difference as you may suspect and you'll likely get a far superior product.

And BTW, 15-25 years is about nearing the lifespan for most single lift asphalt driveways, especially when they're not seal-coated every year or two.

 

[gramps416]

I don't want to do concrete with this project I prefer a blacktop. I have decided to do some interlocking on the walkway. I will do it myself, the first experience with pavers. I am actually pretty stoked about that project.

I think the slope will be ok. I measured just now. 16 1/2 inches over 45 feet from the top to the bottom. the minimum required (11 1/4")

pull up the gravel, stockpile on site, under-cut the soil sub-base, and re-install the gravel along with whatever additional gravel is needed. If that's done, there's no reason the entire driveway can't have at least 2% pitch to it

I am assuming it still needs the few weeks to air out the water? can the gravel be stockpiled on the driveway itself? or does it have to go on say, the grass? I like this method. Is it the only method that can be done in this situation that would work properly? (i just want to see all of the angles)

this is great info btw

 

[Allison1888]

driveway

We have a similar issue with our driveway failing and needing to be completely redone, but we aren't quite ready to bite the bullet on this one. Good luck and post some pics so we can see the results. And--sounds obvious--but do get permits from your town, as this can help ensure the work is up to code, etc.

 

[gramps416]

permits are required where I live. Good call. I was just reading a local newspaper article and it seems that a permit can appear to be useless or an annoyance depending on your needs. I play by the rules, but it appears the permit would not alter the plan for the driveway

 

[jomama45]

I don't want to do concrete with this project I prefer a blacktop. I have decided to do some interlocking on the walkway. I will do it myself, the first experience with pavers. I am actually pretty stoked about that project.

I think the slope will be ok. I measured just now. 16 1/2 inches over 45 feet from the top to the bottom. the minimum required (11 1/4")

You are correct, 2% is about the same as 1/4" per foot.

I am assuming it still needs the few weeks to air out the water? can the gravel be stockpiled on the driveway itself? or does it have to go on say, the grass? I like this method. Is it the only method that can be done in this situation that would work properly? (i just want to see all of the angles)

this is great info btw

If it isn't suitable material when it's wet, I wouldn't consider re-using the material under a new driveway. In a case like this, I'd remove any reclaimable gravel, either store it on or off-site, remove any soft, questionable soil, let it air out for a day or two, and re-install the gravel, compacting it in lifts.

Usually, it's just not feasible for me to tell customers that they can't use their driveway for a few weeks, so we remove all soft soil & start bringing in 2-3" fractured limestone for a base, and finish up with finer gravel. It may take a foot of material to make it solid again, but it's money well invested IMO.

 

[gramps416]

If it isn't suitable material when it's wet, I wouldn't consider re-using the material under a new driveway. In a case like this, I'd remove any reclaimable gravel, either store it on or off-site, remove any soft, questionable soil, let it air out for a day or two, and re-install the gravel, compacting it in lifts.

that's interesting. I was under the impression that the material was good, but there wasn't enough of it. (why i thought they needed to dig down deeper for a thicker base). If you think about it, a base that is not thick will not hold up no matter how good the material is. Where I live, concrete and asphalt must be recycled by law. It just seemed silly to me that this material would end up at the recycler's to be used in someone else's property at the end of the summer.
As a base, one contractor offered a limestone or a recycled concrete content one, which was about $400 cheaper for approx $1000 sq ft.

It seems that, the proper method is expensive, I am wondering if it would be easier if I interlocked the whole thing, and did it myself (with one or two additional workers). Is that something that is doable with rented equipment? would I be way over my head for doing such a job? approx how long would that job take with two or three people total? two weeks @8 hrs day?