Concrete experts

[hogdriver]

I need a pad for a 44 ft Entegra on dual wheels weighing 36000 lbs. I have no idea what the loading per tire is. It seems like I might be cracking my wimpy, barely 4 inch driveway. What do I need to support this beast? When I was in the Air Force we poured 12 in concrete ramps and there was a difference in sitting vs taxiing. My property is in Florida on sandy soil. Should I put down 4, 6 in of crushed concrete then 6 in of concrete w rebar or what? I don't really want to break the bank.

What about pavers? I'm afraid if I just have pavers put down on sand (cochina) base that I'll generate ruts. I've seen some high end RV parks and I think they pour concrete pads first below grade then lay pavers. How to do pavers for a heavy vehicle?

[vsheetz]

I did not do concrete park pad and driveway due to cost. Instead installed compacted DG. has been in place for several years. Works great.

[JMonroe]

If starting from scratch, I'd go ahead and pour the 6", for piece of mind if nothing else, and I'd also feel better with the use of some kind of reinforcement.

I'm sure a local contractor can give advice, but I'm not sure you'll need much between that sand and your concrete.

[FIRE UP]

Hogdriver,
Well Sir, first off, I've seen tons of driveways, RV parking lots, and more that were setup with pavers. I personally love Pavers. I think they have a distinctive look. They're not easy to "creep" around on, with a creeper if, you're the type that does a lot your own work but, there's ways around that. In any case, pavers or concrete, the primary base for either depends up your soil/dirt in your immediate parking area.

If it's expansive or, other types that are generally soft sand or soil, subject to moisture contamination (from rain or snow etc.) then, just about any road builder would most likely tell you to dig down, probably around 16" or so and remove that base soil. Then, install either "Road base" or, something similar to it that can be compacted to a seriously dense base. With a really strong or, densely compacted base, many folks get away with 4" of 3000 psi. concrete. That's the way our brand new home, in Lake Havasu City, that we will be moving into, in about 12 days, is constructed. And that is guaranteed not to crack. Our coach, an '04 Itasca Horizon 36GD with the C-7 CAT, tips the scales at around, 26,120 lbs.

I'm certainly no expert on any of this but, again, I love pavers and, I might just do the prep work that's needed alongside of our already built RV garage for pavers.

But, yep, without a doubt, it's the prep work and compaction that is the key to making a concrete slab survive. That and of course, the mix of the concrete itself and, rebar or, while I've no experience with it, there's a mix of fiberglass and concrete that's supposed to be seriously strong too. I know that a well done, well prepped, and correctly mixed concrete slab is some pretty serious coin, to me, even if it pinches me in the pocket book for a year or two, 'till I recoup, I'd do it in heartbeat, your choice.
Scott

[Tha_Rooster]

Mine destroyed my driveway totally redone this one will handle the weight.

[palehorse89]

Here is some reding on this: https://www.google.com/search?q=conc...+site:irv2.com
Here is a good discussion on the concrete and the ground preperation http://www.irv2.com/forums/f258/concrete-197550.html

[Gocoffeer]

Interesting question...I am going to perform a similar pour and stone compaction for my Bounder later this season. I called upon my brothers advice since he is a home building type contractor and landscaper. He told me to pour a typical 4"pad over the length of the drive way and only enhance the areas where the tires will rest. His advice surrounded on cost of pour and purpose of added driveway. I will design into my pour a grid area under the axle sections and it will be 6 inches with additional leveling humps to drive up onto in the area where the tires will sit. I want to taper the cement for water flow but keep the RV level in the area where I park....so I am designing this into the pour. I will use the local 5000psi cement with the fiberglass enhancement (hog hair) and a reinforcement mesh.
So why not make the whole drive addition 6"? According to my brother it is not the driving over the area infrequently with the big vehicle that will damage the drive....it is the sitting area where it gets weight stress damage.

[rsflight]

We recreated our RV pad several years ago to a complete concrete pad. The old pad was 2" blacktop with a 4" base and 4" concrete pads under the tires. That worked well for us for the 18k# and under RVs for 20 years. The current RV is about 32k# and it would tilt the pads. The new RV pad has 12" of #2 gravel and 6" of 4500psi concrete with rebar and road mesh.

I contacted our local concrete supplier and asked for their recommendations before starting the project. They provided this conservative design spec because they wanted their product to fit our application. Their suggestions matched recommendations from others so I felt comfortable with the approach.

[Cajunman]

Originally Posted by rsflight

We recreated our RV pad several years ago to a complete concrete pad. The old pad was 2" blacktop with a 4" base and 4" concrete pads under the tires. That worked well for us for the 18k# and under RVs for 20 years. The current RV is about 32k# and it would tilt the pads. The new RV pad has 12" of #2 gravel and 6" of 4500psi concrete with rebar and road mesh. I contacted our local concrete supplier and asked for their recommendations before starting the project. They provided this conservative design spec because they wanted their product to fit our application. Their suggestions matched recommendations from others so I felt comfortable with the approach.

I agree with this. Going 6" vs. 4" isn't that much more $$ in the whole grand scheme of things. An important thing to remember is ALL concrete will eventually crack. Concrete has plenty of compaction strength but is very weak when it comes to tensile strength. This is where it is important to install control joint material at the proper spacing. (Some call this expansion joints) This is basically you telling the concrete where to crack and giving it places to move slightly as it expands and contracts with the change of temperature. A good rule if thumb is concrete naturally cracks in square patterns. This is how you want to set up your control joints (keyway).
Next time you are in a parking lot, look down and you will see what I'm talking about.
Btw, I do concrete work in Louisiana with similar type soils as Florida. Lots of swampy, soft ground. Hope this helps.

[Murf2u]

It's pretty common when pouring large sheets of concrete for things like factories to have several different thicknesses for varying loads. No reason you can't do the same thing.

Figure out where the wheels will sit and pour an extra deep slab with more steel in it in those areas, then just pour a 4" slab everywhere else.

[GaryKD]

Hi hogdriver,
I also live in Florida. In 05 I installed a pad for the coach. 6" of reinforced concrete over stamped down sandy soil has worked for me.

[nforus]

We used 6 inch with rebar, fiber mesh, and 4500 psi concrete coach weighs 52,250 pounds, works fine.

Keep in mind that with driveways and pads there's only 2 types of concrete,

1)Concrete that's cracked
2)Concrete that's going to crack

[Ray,IN]

Difference in amount of concrete for a drive 15' wide X 40' long- poured 4" deep takes 7.5 yards; poured 6" takes 11.3 yards. Difference, about 4 yards, not much additional cost for peace-of-mind.

Originally Posted by nforus

We used 6 inch with rebar, fiber mesh, and 4500 psi concrete coach weighs 52,250 pounds, works fine.

Keep in mind that with driveways and pads there's only 2 types of concrete,

1)Concrete that's cracked
2)Concrete that's going to crack

There is no such thing as concrete that will not ever crack. Some think rebar and wire prevents cracking, not so, it merely prevents the crack from becoming wider. Of course from your post, you already know.

[nforus]

Originally Posted by Ray,IN

Difference in amount of concrete for a drive 15' wide X 40' long- poured 4" deep takes 7.5 yards; poured 6" takes 11.3 yards. Difference, about 4 yards, not much additional cost for peace-of-mind.


There is no such thing as concrete that will not ever crack. Some think rebar and wire prevents cracking, not so, it merely prevents the crack from becoming wider. Of course from your post, you already know.

You're right!! And, We've always agreed with the words in the signature on your profile!!