I am planning on building (haveing built) a 30'X64' Pole barn garage and would like to get some suggestions on the concrete flooring. How thick should it be? I know I will have the concrete people put plastic under the concrete but not sure what I need as far as the concrete goes. Any help will be greatly appreciated. Trying to stay away from cracks also.
Concrete, how thick ect. should it be?
- Thread starter 86swb
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shopking68
Well-known member
I got at about 5" all around, almost 8" toward the walls.
Get the stuff with the fiber in it, helps with pulling. No matter what you do, it will crack eventually, just a matter of time
HI, 86swb, its me shopking from the truck forum, small world
Get the stuff with the fiber in it, helps with pulling. No matter what you do, it will crack eventually, just a matter of time
HI, 86swb, its me shopking from the truck forum, small world
5 inches minimum. You can use the concrete with the fiberglass in it, but I woud also ask that they install the wire mesh as well. Be sure the concrete guy cuts control joints with a concrete saw. This is a cut in the concrete so when it's going to crack it will hopefully crack at those joints
shopking68 said:I got at about 5" all around, almost 8" toward the walls.
Get the stuff with the fiber in it, helps with pulling. No matter what you do, it will crack eventually, just a matter of time
HI, 86swb, its me shopking from the truck forum, small world
Hey shopking,
I knew some to the truck board guys were also on here. This is a very nice board when talking about garages. Like the truck board, it is full of information. Thanks for the advice to everbody. I was thinking about going with the 5". I had the fiberglass put in before and it was alful hard to get the little fiberglass that sticks up to go away. Makes it hard (for me anyway) to coat the top of the concrete. Is there an easy way to get the fiberglass off of the top of the concrete? Again, thanks or the tips.
Some suggestions to consider for your new building:
1. If you are considering in-floor radiant heat (the best but the most $$$$), your floor needs to be built differently than just a slab. With radiant heat, you will probably end up with 6"+ concrete thickness plus considerable insulation and vapor barrier. Consult an experienced heating contractor for recommendations. Without radiant heat, insulation and a vapor barrier are still recommended if you live in an area where frost is likely.
2. Not less than 5" overall thickness should be OK if you don't have any heavy concentrated loads. A jib crane or something similar should have extra footing under the base.
3. Wire mesh or crossed re-rod is strongly recommended.
4. The perimeter of my shop is 12" deep x 14" wide with 10" under a load bearing wall inside.
5. If you are going to coat your floor with epoxy (U-Coat-It, etc.), don't put a curing compound on the floor. The floor prep for the epoxy will be much easier and the coating will adhere better. Also, don't allow your contractor to run rubber tired equipment (lifts, vehicles, etc.) on the floor. Tires have silicone in them that will scuff off onto the floor and the epoxy will not adhere to those areas very well.
6. If you can, let the floor sit exposed for several weeks before building on it. This will allow the concrete to cure more completely which will greatly reduce the chances of cracking. Mine sat for 9 weeks with no curing compound on it before we built. That was in the summer of 2003 (more than 2 1/2 years ago) and so far I have one crack about 4' long.
1. If you are considering in-floor radiant heat (the best but the most $$$$), your floor needs to be built differently than just a slab. With radiant heat, you will probably end up with 6"+ concrete thickness plus considerable insulation and vapor barrier. Consult an experienced heating contractor for recommendations. Without radiant heat, insulation and a vapor barrier are still recommended if you live in an area where frost is likely.
2. Not less than 5" overall thickness should be OK if you don't have any heavy concentrated loads. A jib crane or something similar should have extra footing under the base.
3. Wire mesh or crossed re-rod is strongly recommended.
4. The perimeter of my shop is 12" deep x 14" wide with 10" under a load bearing wall inside.
5. If you are going to coat your floor with epoxy (U-Coat-It, etc.), don't put a curing compound on the floor. The floor prep for the epoxy will be much easier and the coating will adhere better. Also, don't allow your contractor to run rubber tired equipment (lifts, vehicles, etc.) on the floor. Tires have silicone in them that will scuff off onto the floor and the epoxy will not adhere to those areas very well.
6. If you can, let the floor sit exposed for several weeks before building on it. This will allow the concrete to cure more completely which will greatly reduce the chances of cracking. Mine sat for 9 weeks with no curing compound on it before we built. That was in the summer of 2003 (more than 2 1/2 years ago) and so far I have one crack about 4' long.
I thought about the radiant heat, but as you said "$$$$$". More concrete ect. I am also planning using the U-Coat-It over the concrete. I am leaning towards the wire mesh in the concrete. Also as suggested by sjsfire, have cut joints in the floor. Thanks. Everthing has been very helpful so far.
wienerwater
Active member
The most important part for pouring concrete, is the base prep. Make sure the base material has been compacted several times in layers with suitable material, prefer "3/4 road crush". This has some sand in the crushed gravel, and when put down in about a 4" layer, hose it lightly to make it damp, then use a gas powered compactor. Do several layers like this, and itself will be hard as concrete. You want a minimum of 4" concrete, for general light traffic (car etc). Wire mesh is more of a binder, where it holds concrete together, should it heave and crack up, or for joining to seperate pours, such as the garage floor to the front apron.Wire is left sticking out about 4-6 feet from the first pour, and will hold the two together.Rebar is bette, 1/2", placed in 2-3 foot squares, and is cheap to buy from most concrete suppliers. Building supply stores seem to charge a LOT more for rebar/mesh. As far as expansion joints, you don't need dusty saws and cutting. You use what is called and "expansion strip", which is a long strip of plastic material, approx 1 1/2' deep(looks like a "T"), and cheap to buy. When the cement is setting up, you press the long part into the concrete, wait an hour, and the top of the "T" snaps off, leaving a clean plastic piece about 1 1/2" embedded in the concrete, just below flush of the surface. Joints need to be max 10' apart in either direction, since that's where concrete will crack at on a normal basis. Use minimum 35mpa concrete, as it's stronger and well worth it.
Sorry for going off topic a little, but just want to share a bit of knowledge passed on by some good pros, from my past projects.
Sorry for going off topic a little, but just want to share a bit of knowledge passed on by some good pros, from my past projects.
NHCharger
Well-known member
Weiner is right. 5" of concrete won't hold up if the base isn't prepped right or is poor material. I've built over 100 garages and unless they are for commerical use or request a thicker floor I pour a 4" slab. I use both the fibermesh and wire in the floor. Last year my floor guy began using the plastic expansion strips. they look a lot better than the grooves cut in the floors. In my shop/garage I went 4" but where I am planning for a two post lift I poured 8". When building the garage I had my bucket loader/backhoe on the concrete floor to help lift up the walls. No problems with the concrete cracking from the wieght.
sberry
Banned
This is one of the best basic threads I have seen on this type forum about slab pours. Something else is to keep it wet as soon as it sets, turn on the garden sprinkler for a couple 3 weeks especially if its cooking hot out. Its nice not to pour in the blazing summer sun. Good concrete needs to be kept warm when its cold out, cool when its hot out and wet while curing for the best results, the difference is signifcant. Just as soon as its finished you can cover with straw and irrigate, want to be super pro irrigate constant for 28 days. I am a lazy finisher, my own work isnt anything to write home about but with some basic care you can make double the hardness. Ideally it would be nice to stay off it for cure time, shotblast then epoxy system. Never works out ideally it seems. This is a place it may pay to get some help, a couple good finishers are worth their weight, When I do critical flatwork pours I use someone in the biz I know.
86swb said:
You can try 2 things to remove fibers:
(1) Burn them off. With enough heat you can burn them off. They will melt into little balls that can be broomed off. I've used my MAPP gas torch and a propane torch (much more heat over a larger area) on my floor. I was able to remove most of them in this manner
(2) If you are going to epoxy the floor, you can remove them after you lay down the first layer of epoxy. The epoxy will cause the fibers to protrude through the epoxy making them easy to sand away. I used a palm orbital sander to remove these fibers, then laid down the second layer of epoxy. No more fibers.
I did both above. No matter how well you think you burned off the fibers, some will remain. #2 takes care of the remaining fibers.
rrangus
Well-known member
I would suggest that you use 5000# concrete mix. Finishes real nice and quite a bit stronger than standard mix
GLF
Member
Don't forget to slope the floor to the main door/doors. I would compact the soil, after grade, then 4" of sand covered with 6mil plastic (no seams) and 3/8" rebar 16" oc. Use at least 3000psi concrete with expansion strips (or deep scores every 100 sq ft
krooser
Well-known member
My floor is 4" with a 3500# PSI rating...fibermesh...with a Weaver 9000# lift...no problems after 10 years on the job. I personally think wire mesh and rebar are real overkill in a home shop/garage. I've got a 1500# vertical mill, an old tronworker that's gotta be 3000 lbs, a jib crane and LOTS of other shop equipment. And I run a forklift in and out on occasion.
Plus, at any one time, I may have one or two cars inside plus several complete engines on the floor...
Rent a floor sander and you'll have those fibers removed from the floor finish in less that an hour....
Plus, at any one time, I may have one or two cars inside plus several complete engines on the floor...
Rent a floor sander and you'll have those fibers removed from the floor finish in less that an hour....
craigibc
Well-known member
Is there any update on this info on here anywhere? Any new conversation on what to use for the new install of concrete in a shop? I want to park cars in the shop.
Thanks,
Craig
Thanks,
Craig
rburke65
Well-known member
I wouldn't think there would be any new and improved "updates" of info. Compacted base, vapor barrier, 3,500 TP 4,000 mix and strips or cut. You realize that a 4,000 mix is rated at 4,000 lbs. on every square inch of floor, right! I don't know what in the hell you'd be parking on a garage/shop floor to require a thicker slab. I can understand under a lift but a 4" floor is more than adequate.
astroracer
Well-known member
The best info you can get is right from the horses mouth. Go to the BendPak site, search "concrete requirements". they have a complete list of their lifts with their recommendations for concrete PSI rating and thickness.
For a 2 post hobby lift rated to 10K they recommend 4" of 3,000PSI concrete. If you bump the PSI up to 3500 you would be good.
Mark
For a 2 post hobby lift rated to 10K they recommend 4" of 3,000PSI concrete. If you bump the PSI up to 3500 you would be good.
Mark
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6768rogues
Banned
Take your time spreading and compacting the base, it is important to have uniform thickness in your concrete.
As soon as you are able (typically the morning after the concrete was placed) put on a heavy coat of curing sealer. As concrete cures it forms a microscopic matrix and pores open up. Sealer will seal up some of the pores and slow the cure, making the finished product stronger.
Don't let them add water or trowel water in. Bleed water that comes to the top should evaporate or be dragged off with a hose. Working it in will weaken the top of the concrete.
My 2 post lift required 4" of reinforced 3500# concrete. I used 5" of 4000# concrete with fiber mesh, and #4 bars every 2 feet in both directions.
Fiber mesh keeps it from separating when it cracks, it does not provide structural strength. Rebar adds structural strength when placed in the tension side of the slab.
Don't be in a hurry. The design strength is where it should be at 30 days.
As soon as you are able (typically the morning after the concrete was placed) put on a heavy coat of curing sealer. As concrete cures it forms a microscopic matrix and pores open up. Sealer will seal up some of the pores and slow the cure, making the finished product stronger.
Don't let them add water or trowel water in. Bleed water that comes to the top should evaporate or be dragged off with a hose. Working it in will weaken the top of the concrete.
My 2 post lift required 4" of reinforced 3500# concrete. I used 5" of 4000# concrete with fiber mesh, and #4 bars every 2 feet in both directions.
Fiber mesh keeps it from separating when it cracks, it does not provide structural strength. Rebar adds structural strength when placed in the tension side of the slab.
Don't be in a hurry. The design strength is where it should be at 30 days.
I just had my concrete done for my pole building. I went 5" thick with fiber and remesh in it. They also put plastic under the remesh. I had them put a drain in as well. I just had them run the drain out the back of the building into a hole in the ground full of gravel. That way it is there if I ever want to tie it into my sewer. Mine has been in for a week with no visible cracks for now. Although my contractor guaranteed cracks. The two most important parts of the whole pour is where and how deep they put the control cuts and the foundation beneath the concrete. Three things to keep in mind about concrete. It is hard, it will crack, and nobody will steal it.
Attachments
What are you storing in the building? Whats your heaviest vehicle?
Whats the plastic doing for your slab? Are you worried about moisture getting into your pole barn?? Are you conditioning the space?
OP posted this thread 3/2/2006 and his last activity here was 9/10/2008, almost 9 years ago.
Just so you know.
astroracer
Well-known member
We know... The thread was brought back from the dead with a viable question in post #17...
Mark
maybe its time for a thread closing policy...like after a year!
like2wheel
Well-known member
Why?
What's the harm?
Often threads are resurrected because people searching found good info.
va.grouseman
Well-known member
6'' thick slab with a 6 bag mix, (that's 6 bags concrete to the yard).---It will be green first, then turn blue, then white.---You can park anything on it you want.---You'll probably want to put in one or two expansion cracks.