More questions about paved driveways

[Mosey]

I’ve had 4 companies come out and give me estimates on paving my driveway. Prices range from $1/square foot to $1.50/square foot. One of the things that I wasn’t aware of when I first started thinking about getting the driveway paved (see ) is that weeds could come up through the asphalt if they are not killed first. I find it amazing that weeds could grow up through 3" or more of asphalt! So, the paving companies all said they would spray weed killer before paving. I got concerned that the weed killer would damage trees and did some research on that (see <A target="_blank" HREF=http://www.tractorbynet.com/cgi-bin/compact/showflat.pl?Cat=&Board=projects&Number=182233&page=0&view=collapsed&sb=5&o=0&fpart=>weed killer basics). My conclusion is that it’s not worth taking a chance on damaging the trees.

So, my question, and the reason for this post, is “Will weeds really grow up through 3" or more of asphalt?” Does there need to be a crack there first, or will weeds just come right up through the middle of it? It really seems to me that something like Roundup would be enough, but maybe not. If weeds don’t come up through landscape fabric, then why would they come up through asphalt? I’m not really that concerned about most of the driveway because it’s been gravel for 20 years and I’ve been spraying it with Roundup to keep the weeds out. But, there are a couple of areas that are grass and weeds right now (dandelions and other broad leaf weeds) that I plan to have done along with the rest to increase parking space. Would it help to put landscape fabric under that area? All opinions welcome! Thanks.

 

[yooperdave]

Mosey,

Weeds will grow thru cracks in 4" asphalt pavements, 6" concrete pavements, thru bolders, on top of industrial roofs- any place where water can collect.

Roundup and a landscape fabric are a good starting point.

The weeds can also start from the top and work their way down the crack. Routine maintanence will keep them at bay.

Yooper Dave

 

[snowman]

Mosey;

I had my driveway paved last summer - about 12,000 sf at $1 per sf.

They did not put anything below the pavement (was formerly a rough gravel road); just prepped it by bulldozing it, bringing in some stone, and compacting it.

I doubt you'd have any problems with weeds growing up through the pavement; I don't worry about it.

Even if they put some type of weed killer down first, I would think it would only last a short while before it's absorbed into the soil and would have no future benefit.

 

[HickoryDean]

Mosey
It's not so much that weeds are going to grow through the pavement with landscape fabric, but some soil will accumulate in pockets which will permit weeds to grow. You can use Roundup or just mow the blacktop driveway.

 

[JIMCT]

I had my driveway repaved 2 years ago next month and I have noticed some weeds or blades of grass growing right through the asphalt where there are no cracks. That said, there have been only a few and have all been within 2-3" of the edge where the asphalt meets the lawn.

Jim

 

[fishman]

Mosey,

In my area what we call "nutgrass" drives me crazy. It will go through 5 layers of weed barrier like it's nothing. On the bright side, after it does, Roundup works nicely./w3tcompact/icons/grin.gif I don't know about asphalt, but it might make its way through it. I'd just worry about that if it happens and spend 10 minutes and $5 on a Roundup application.

 

[phalynx]

Weeds will flat out grow anywhere. I had to drive through a field once of 3' high weeds. All of the seeds just piled up on my hood and finally came to rest between the bug sheild and the hood of my truck. I figured they would blow out. Low and behold, they all sprouted and grew 4 inches. This, on my hood. Goes to show you.

 

[Molerj]

Weeds, especially dandelions will come straight thru the asphalt. It is hard to believe, but
I've seen them push the asphalt right up & pop out. The top soil should be completely
removed & a good base installed before applying the asphalt. Then again, I prefer cement.
The cost when I did my 225' X 12' drive wasn't that much greater.