Concrete slab thickness for a newell

Newellin Thunder · 08-19-2012, 07:51 PM

Do I really need anything more than a 4" concrete slab to support a RV? I am preparing to put up a shop large enough to house the Newell and it was recommended that I put a 5-6 inch slab of concrete to support the weight of the Newell. Is this correct or will 4" be just fine.

jack14r · 08-19-2012, 08:47 PM

I have 6 inch in my shop and I wish I had 8 inches because of cracks,maybe I should have used 4500 PSI concrete instead of 3500 PSI.

Dom Ferris · 08-19-2012, 09:08 PM

Not if you like to look at big cracks!! I mean in the concrete. I wouldn't think of less than 6" with reinforcement. You could probaly hear 4" breaking under you.

Retired63 · 08-19-2012, 10:01 PM

What's your sub-base (soil condition)? With the proper sub-base and 3000 psi fibered concrete 4" might be doable

Neweller · 08-20-2012, 04:02 AM

Jack14R and Retired63, you both have the right idea. I'm in the planning stages too on building either a 40 x 80 or 50 x 100 shop. I have been going over things with a contractor who is telling me I could split the slab in half with one half 6" thick and the other half 4" to save money. Of course the 6" thick would be for working on a Newell or equipment etc. Now the fiber reinforced concrete came up as a good option allowing me to go with a thinner slab than without. 3/8" rebar 12" on center is another option for superior strength. I would say the ultimate might be an 8" 4000 psi with fiber reinforcement. Which is spendy and probably overkill.

Ken

The Newell · 08-20-2012, 06:07 AM

As long as you have good preparation before you pour, and use the fiber reinforcement, you should be ok with the 4" slab even though I would recommend a 6" if it were me. The problem with concrete cracking is when it is on poorly prepared soil and/or not reinforced properly. Concrete generally cracks when there is movement beneath it, or it's uneven somewhere.

But if it really concerns you, pour an extra foot near the rear where the bulk of the weight will be.

I'm not an expert on concrete, but I did stay at a Holiday Inn Express last night

tuga · 08-20-2012, 03:24 PM

I was at Newell factory, and they were breaking out a section of concrete that had many cracks. After the old concrete was broken out and removed new back fill was put in and leveled. For 8 hours a worker using a compactor machine packed down every inch of that area. The section of concrete was about 20' x 20'. I don't know how thick the area was but I would guess 12"!

The area that was prepared was in the middle of the driveway that had Newells rolling on it constantly all day - every day. My service work was finished before they poured the concrete so I didn't get to see how much re-bar was put in the section.

Personally, I believe that no matter how thick, or how much prep work is done - the concrete is going to crack. Of course I also believe that thicker is better and it should last longer.

Just my .02

smagown · 08-20-2012, 10:58 PM

I just built my shop, 40 x 60 with 5200 sq ft under roof. I used 5", rebar, fiber, and 27 8 ft pilings. Concrete alone was $16k. It hurt my feelings!

Thanks,

The Newell · 08-21-2012, 12:16 AM

That is a nice size shop you built Steve. Did you set it up to accompany some fellow Newell owners? and if so do the cars come with the visit ?? lol just kidding Steve about the cars.

smagown · 08-21-2012, 12:46 PM

Thanks Joseph. I'm set up with full hookups for fellow Newells. Ron got a hot lap in the GT3, all grins!
Thanks,

larryweikart · 08-21-2012, 01:09 PM

[ATTACH][/ATTACH]We built our storage facility in 2001 with 5", 3500psi concrete and adequate rebar and we have no cracks to date(knock on wood) It has a 8"X12" footer dug in around all outside walls. This is pretty good results considering the Mi. weather changes and the fact that we have the Coach, with trailer attached, stored together at a total weight of approx 65,000lbs. Our contractor spent substantial time preping the area before pouring. Hope this helps.

lbrachfe · 08-21-2012, 01:44 PM

Simply have your Newell weighed and contact a concrete company for the proper composition and PSI for your load and the proper depth and material for the sub base and as Tuga stated Prep is the key as it is in all construction. My guess from 35 years building is a sub base compacted to the freeze line or in warm climates 30". Use a minimum of 4500psi fiber laced concrete and 1/2 rebar boxed and wired in 24" pattern. Concrete depth depends on your natural base and fill, but no less than 6" depending on all other factors and score expansion joints in a pattern and more if you have a severe pitch. Good luck and you should be crack free....

bigcatwally · 08-23-2012, 01:30 AM

Quote:

Originally Posted by larryweikart

[ATTACH][/ATTACH]We built our storage facility in 2001 with 5", 3500psi concrete and adequate rebar and we have no cracks to date(knock on wood) It has a 8"X12" footer dug in around all outside walls. This is pretty good results considering the Mi. weather changes and the fact that we have the Coach, with trailer attached, stored together at a total weight of approx 65,000lbs. Our contractor spent substantial time preping the area before pouring. Hope this helps.

Larry nice building!

FJGuard · 08-24-2012, 10:33 AM

Wally's right! Larry you've got a nice place to keep the Newell from being out in the weather. Mind if I ask what it cost you for the setup?