Concrete driveway difficulty

BX23Seattle · Jun 10, 2005

Everyone on TBN is so knowlegable in many area's I thought I would ask for imput here.

I have a 350 ft gravel driveway which I would like to make into a cement driveway with a boomed finish. Most of the driveway is on about a 12% slope. Has anyone installed concrete on a slope like this and have any thoughts on this idea? Any tricks to be aware of? I could have asphault installed but I prefer the look of concrete, it will actually cost less due to the free labor and hopefully end up with a driveway that will outlast asphault.

Dargo · Jun 10, 2005

I've been working on doing my driveway for years now. My issue is that my driveway is nearly 1000' long. /forums/images/graemlins/frown.gif From experience, a good concrete driveway will almost certainly last longer, require less maintenance, and will carry considerably more weight than asphalt if thick enough.

Personally I am going with 6" of 5000 psi fiber reinforced concrete with 6 gauge wire matting and #10 rebar sticks pinning each section together as well as running throughout the slabs. I'm only about 25% of the way complete, but all is well.

On the areas with a slope, they simply poured it with a different slump and there were no issues. On the side of part of my existing bridge, they actually poured concrete up a 80 degree angle! /forums/images/graemlins/shocked.gif When told how and where the concrete is going to be used, most concrete companies will know what to recommend. I need a strong driveway as I have some heavy trucks back on occasion. Even with the strength of my concrete, it has definitely cracked. It just hasn't gone anywhere at the cracks. Therefore, it's working for me. I fully expect it to last me my lifetime. Good luck! I'm only too familiar how hard it is to round up good help. /forums/images/graemlins/wink.gif

I assume you have a good gravel base, which helps. You may want to see how much more the fiber reinforced concrete will run you. The professional concrete guys and the concrete delivery guys speak very highly of the added strength. I had to have one section taken out due to a problem, and it was the most difficult section of concrete I've ever had to remove. Besides the heavy gauge wire and rebar, that fiber seemed to prevent us from getting any chunk out without the greatest of resistance.

There is 65 yards in my barn floor, and every single bit of it had to be hauled in by wheelbarrow because of the first concrete truck getting hung up in my wet yard at the start of the pour. I had a dozen helpers fortunately. By the end of the pour, nobody wanted to come back. /forums/images/graemlins/crazy.gif

EddieWalker · Jun 10, 2005

I've done driveways and small pads, but nothing like what your attmepting. WOW!

Since concrete expands and contracts with the weather, it's real important to put some expansion joints between your pours.

How solid it your base?

Be sure to leave several feet of rebar sticking out past your forms to tie into the next pad.

How big will each pad be?

Ten feet is probably the minimum for width, with 12 feet being better. The length of each section could really be what determines how well it turns out. Too long and you wont be able to finish it before it hardens. Too short and your driving over expansion joints every second.

For basic auto traffic and slow moving heavier trucks, a 3 1/2 inch pad will be plenty thick enough.

Are you sure you can do this cheaper then blacktop?

Price of rebar, forms and concrete plus more hours then I can figure to finish. Depending on how large the pads are, you'll need a minimum of three guys. Two for the scree board and one more to move material around. If it's warm out, you'll need more guys or pour less material.

Do you have an alternatvie route to drive into you property? Is it year round accessable? This is gonna take a very long time, you have to be ready for rainy days and the possibility of muddy conditions if your just driving around the spot your woking on through a field. Worse if you have trees to contend with.

Speaking of trees, are any close enough that threir roots will eventually crack the cement? Are any close enough that the weight of the cement will kill off the tree by damaging the roots?

Blacktop is quick, clean and simple. It's hard to believe you can do that much concrete cheaper then blacktop, especially if you figure out the time and effort involved.

Good luck,
Eddie

Bird · Jun 10, 2005

( hard to believe you can do that much concrete cheaper then blacktop )

I'd generally agree, Eddie, and sure haven't kept up with prices in a long time, but when we built a new auto pound in Dallas, on the first phase it was cheaper to use asphalt for the parking lot (15 acres), but a couple of years later, when we did another 15 acres, it was cheaper to use concrete. /forums/images/graemlins/confused.gif Fluctuating prices can be confusing.

LarryD · Jun 10, 2005

You shouldn't have any problems with that slope, just screed uphill. A 3½" slump will stick pretty good but is a little harder to place. It sets-up quicker as well so have the broom handy.

Follow the advice given and make sure you've got good compaction under the crete, the base course is just as important as the top layer.

BX23Seattle · Jun 10, 2005

I will be hard pressed to find somone to do blacktop for $1 sq ft in my area, the concrete route may not save me any money up front but over the longevity is where the real savings will hopefully pay off and the cost are only similar because I would be doing the labor myself.

350 ft long x 12 ft wide x 4" deep = 52 yards of concrete
Concrete is about $62 yard = $3,224 plus metal grid, rebar, forms which I'm not sure how much that will pencil out to.

It would cost about $4,200 for blacktop if I can find someone to do it for $1 per sq ft.

No trees to deal with, I already have a nice gravel base that has been packed down with traffic for the past 1 1/2 yrs.

I was thinking of cutting in the expansion joints a couple days after the poor, any drawback to that?

Other problem I may run into is with the cement truck being able to empty it's entire load while backing up my driveway. Not sure how flat the truck needs to sit to empty it's entire load. I have good access to my house through the neighbors property while I work on this but he is not going to want cement trucks using this route over his yard so I am left with the trucks backing up the driveway so we can start at the top and work our way down.

johan3400 · Jun 10, 2005

The concrete should remain more economical. The asphalt contractors in our area have shared the the higher prices of Crude oil have their prices up. I am pricing pouring a 250 foot driveway and the concrete is much cheaper. I am fortunate, the driveway is virtually level and has had a gravel base for many years. Others have already given you good sound advice, have fun pouring!

Dargo · Jun 10, 2005

( I was thinking of cutting in the expansion joints a couple days after the poor, any drawback to that?)

On mine, I was told that every so many feet I needed to use the 1/2" spacer with the pads pinned together with rebar. Then use the expansion joint filler on top to fill the crack. The stuff comes in a roll. After the concrete cures, the top 1/2" or so of it is perforated so it peels off to leave a nice uniform area to place the filler. Doing it that way will help prevent it from buckling on really hot days. I think on mine every other joint is cut in. The "other" joints are the expansion joints that are pinned with rebar but filled with the joint sealer. If you talk to a concrete guy, he can give you the distances that require this type of expansion joint. The cut in joints only control cracking, not expansion. The idea is that your pad cracks in the cut in joints, not randomly. The cut in joints do not allow for expansion and contraction.

Also, I was told to use smooth 1" round stock to pin my pads together. Supposedly the rough texture of rebar will not allow the pad to move and will cause a crack at that point. The smooth 1" round stock holds the pad together vertically, but allows it to expand and contract while sliding on the rod. Another guy said that if you don't want to buy the smooth stuff, you can wrap the rebar with duct tape before you pour. The tape will eventually rot away, but it will leave a space that will allow the concrete to move over the rebar. If you look at where they are pouring highways, they use the smooth 1" round stock on little "horses" that keep it in the middle of their pours.

BX23Seattle · Jun 10, 2005

Thanks everyone for the great advice! I am really looking forward to the day when I no longer need to maintain my steep gravel driveway. Now all we need to do is settle on a date for you all to come out to the Pacific NW and help me get this job completed /forums/images/graemlins/smirk.gif