Pole barn concrete

[jimmysisson]

I'm always nattering at people to put at least an inch of xps foam under a slab in an unheated building, also to cut down condensation. Costs 50-60 cents a sf. Not sure where you're located - this matters more in humid northern climates.
Jim

 

[Rodmo1]

I am curious what strength you would recommend if 3500 psi might be to weak? I am limited to a 4" pour due to the high side not being dug out enough. I am planning on doing a vapor barrier but was not intending on doing the foam underneath. Would this really make that big of a difference? I live near Harrisburg PA. The garage will be heated throughout the year so long as propane is still affordable. Probably only to 50-55 degrees though.

Rod M.

 

[Duffster]

I am curious what strength you would recommend if 3500 psi might be to weak? I am limited to a 4" pour due to the high side not being dug out enough. I am planning on doing a vapor barrier but was not intending on doing the foam underneath. Would this really make that big of a difference? I live near Harrisburg PA. The garage will be heated throughout the year so long as propane is still affordable. Probably only to 50-55 degrees though.

Rod M.

I would use a 4000 or 4500 psi mix

If the building is to be heated I would strongly reccomend at least 1" of foam under the floor, than you can pretty much skip the vapor retarder

 

[Frosty2]

Having a pad poured in my 30 x 30 implement shed that I'm enclosing for storage this week.Using fibre type 4" thick w/plastic vapor barrier.Trowled surface finish for $2200.I've seen prices as high as $4/square foot around here (Chicago).I'm glad I know a finisher that isn't too busy to help me out and allow me to save a buck or two.Next up is replacing the roof and adding a 12 foot lean-to bay that will hold my enclosed trailer.After I install the 12 x 8 insulated commercial garage door and a 4 foot steel man door I'm going to have a nice building.

 

[JonKioti]

Geez Dargo. that's a nice driveway. I'm thinking yours is the place to go when the bomb hits.

Rod, if you can put any foam at all under the slab it's worth it, as otherwise you will be using a fair amount of your propane heating the ground in all directions. I usually use both a 2" subgrade product as well as the vapour barrier. The cost is a bit up there but well worth it.

Most of the time I've used a 3500 psi concrete; I usually try for 4" thinkness.

You are dead on with the idea of ordering in your name and hoping the finishers show up. If you don't feel comfortable with Tuesday's quote then ask the concrete companies. They know who pay their bills; if the finishers are doing shoddy work then they probably aren't paying their bills on time, either.

Jon

 

[Rodmo1]

Okay...Got the second quote today and it was for $2300.00
Went ahead and made the deposit of 50% they should be out next week to do the pour. Quote includes 10 gauge wire reinforcement and 4000 PSI mix. This is for a hand trowel finish. I just didnt want to bother getting more quotes and postponing the pour since I am held up until it is done. Hopefully this is a good price. This quote was about a $100 more then the under the table guy however they are including the wire in the price and they will take care of everything including stress cuts. Now I have to decide if I want to shell out several more hundred dollars on underslab insulation. If I do I will probably go 1" thick.

Rod M.

 

[schmism]

i just had a 20x26x4" pad poured out front my pole barn.

included excavating area 4" they hand dug the edges to 6" per my request.

Mag finish (smooth, no broom finish) and saw cut control joints.

6 bag mix with fibermesh.

total price $1750 (3.37/sqft)

 

[JMER817]

Saw this thread and forwarded it to my concrete buddy....here is his reply

1,000 bucks is a reasonable price for pouring and finishing 10 yards of concrete. It depends on what this guy wants' , a less skilled cheaper guy (which you can always find a cheaper guy) or a reasonably priced experienced guy.
With a 4" thick slab you should cut control joints at 12' on center maximum (this is a typical commercial spec). The more control joints the better.
Fence reinforcing?????????????
6 X 6 1.4 gauge wire mesh reinforcing would only cost $200.00 bucks.
If it were me, I would use Steel fiber reinforcing mixed into the concrete at 20Lbs a yard. This would coast the same 200 bucks as the wire mesh reinforcing and does a better job.
110.00 a yard for Sat. delivery seems high, but I guess it depends on where you live.
3,500 psi concrete is not strong enough. The typical spec for this type of pole barn pour is 4,000 psi (with real cement, not fly ash or ground slag cement).
When I did you're slab I followed the commercial spec that I mentioned above.
And yes, concrete is garneted to crack. All you can do is try to control the cracks.
The foam around the pole barn posts are not going to help anything........The foam will eventually fall apart and leave a void. Don't use the foam around the columns.
Buildings that are heated all year round should have 2" X 24" horizontal perimeter insulation underneath the slab.


Signed,
You're local concrete expert

 

[Dargo]

... I would use Steel fiber reinforcing mixed into the concrete at 20Lbs a yard. This would coast the same 200 bucks as the wire mesh reinforcing and does a better job.

The reason I said that I'd rather strongly avoid the fiber reinforcing crap is due to the fact that I've torn out a few hundred yards of concrete that was only about 5 years old that had that in it. I was shocked at how easy it was to rip out that concrete as compared to concrete with heavy gauge steel reinforcement wire. First off, the slabs with the regular fiber were just a plain joke. A whack or two with an 8 pound sledge and I could knock off 2' to 3' sections with ease. The slabs that had the steel fiber was even more of a joke. All that was left of the 'steel fiber' was rust spots! In as little as 5 years it was gone! I suppose it takes very little time for tiny steel fibers to rust away. After a few more contractors tear out slabs with those 'miracle' new advances like steel fiber as opposed to regular steel wire mesh and rebar, I doubt you'll see anyone selling it. Unless, of course, you only want reinforcement in your slab for less than 5 years. Sorry, but after physically tearing out plenty of concrete that stuff is a complete joke. The hardest stuff to tear out is a pea gravel mix with the 1/4" thick rebar matting. It requires the use of a demolition saw to cut the broken slabs apart and is a real PIA to tear out. Slabs with only that fiber stuff in it are a dream to tear out. It's about the same as old concrete with no reinforcement.

 

[JonKioti]

I had what must have been a 30 year old floor with 3/8" 4" x 4" woven wire mesh to cut through once. We discovered after the pros had left we needed a bigger hole, and the next contractor was waiting to proceed - on a Saturday.

I got good with a sledge hammer and angle grinder that day.

I say put it all in the mix - fiber, steel, fence, mesh.

Good luck - how is it working out?

Jon