Before the Pour

[Jessupftw]

Hi Everyone,

Long time reader, first time poster here....

I'm proud to say that after many years of planning I finally had a 50 x 80 pole barn put up last fall. 14' side walls with 2 12' doors on one side wall. Now that spring is starting to sprung in the great state of Wisconsin, it's time for me to think about getting that concrete poured....

My plan is vapor barrier, insulate the floor with 2" of XPS (4x8 sheets) and then have 5" of high PSI concrete poured with rebar and fiber mesh. I'm roughing in plumbing for a bath that may or may not ever happen, 1" water line for a future well, and 30' trough style drain in the center that will shoot out to grade per code.

I've ruled out radiant floor heating just due to my use case. I don't plan on being in there every day and perhaps at times a week or more due to work travel which BTW is very inconvient , work that is HVAC will be forced air on LP so nothing below slab...

What else should I be considering? I think I have all my bases covered but just want to make sure given the permanence of concrete

I'm thinking about a two post rack down the road, should I have piers/footings put in now for support?

Thank you!
Jessup

 

[dw1]

You could fab some pvc conduit under the slab for any electrical items, if needed? Sounds like you have it down

 

[slidehammer]

I'm thinking about a two post rack down the road, should I have piers/footings put in now for support?

Mohawk's new slab recommendations are about the strictest I've seen. If you follow their rules you should be more than ready for any 2-post:

http://www.mohawklifts.com/library/manuals/Slab_Require_Recommend_11_07.pdf

 

[USAFpj]

Hey slide- glad that Mohawk is better at their lifts vs. their spelling- Recommedations?? I recommend a dictionary

 

[Ironhorse74]

windows print screen


OP you didn't say where you are from. Makes a huge difference for wether to insulate the pad or not. I am in the Pacific Northwest and 40 degrees is a cold day. I opted to not insulate. I did install a vapor barrier. I also thickened a trough 2 feet wide with number 4 rebar for a lift. There is no way I was going to pour 4000 pound concrete.

 

[rslaback]

If you do any small engine work you might want to consider recessing in a lift table.

 

[matt_i]

I think you will have a nicer finish without the fibers added to the concrete, with rebar set 16" to 24" on center I do not think you would ever need another fiber added.

Not sure if you are going to get much benefit from the XPS foam without the radiant tubing as I personally believe the heat path thru the ground from forced air heat is a pretty slow one. I would personally put that money into washed limestone 3/4" spread and compacted as a base.

One consideration about setting rebar is you cannot drive the concrete delivery trucks thru the field of bar. So its a good time to start finding a concrete pumping company.

GripRite ProLok makes a rebar chair that's fast and easy to setup.

 

[wssix99]

Mohawk's new slab recommendations are about the strictest I've seen. If you follow their rules you should be more than ready for any 2-post:

http://www.mohawklifts.com/library/manuals/Slab_Require_Recommend_11_07.pdf

^ Great advice.

You'll notice that modern lifts don't require piers or "footers." They are designed to be installed on flat slabs. (Anything else can cause your floor to crack.) So, a nice, thick, flat slab will put you in good shape.

Being in Wisconsin, I'd still put in the tubing for radiant floors - particularly if you are going to be on LP. They do great for heating the space up when you need it and it will keep the heat low in the room vs. a forced air system which will put all that heat in your rafters. (This should allow you to economize on how much LP you are burning.)

 

[bmes1982]

The problem with in floor heat is that it has to be on all the time to maintain temperature. I stayed at a friends cabin last weekend, it's built on a slab with in floor heat. We got up on Friday afternoon and turned the heat on it and took until Sunday morning before it was comfortable. If you're using in floor heat you need to keep it on all the time for it to be effective, otherwise it's a waste.

 

[MagKarl]

Don't waste your money on foam, use that money elsewhere.

 

[NUTTSGT]

Where are you bringing the power in at ? Doing it underground ? Don't forget the conduit for that.

 

[Disney]

Lay out exactly where you want the lift and stub it out for in floor lights before you pour.

How I did mine....
http://www.garagejournal.com/forum/showpost.php?p=4534373&postcount=20

 

[darwyn]

Think about adding something to the floor you can pull a car in with using a chain. Body shops use anchor pots in the floor to straighten frames and such. I'm planning on putting a couple in when I pour my floor, certainly one near the lift.

http://www.ebay.com/bhp/anchor-pot

 

[Disney]

Think about adding something to the floor you can pull a car in with using a chain. Body shops use anchor pots in the floor to straighten frames and such. I'm planning on putting a couple in when I pour my floor, certainly one near the lift.

http://www.ebay.com/bhp/anchor-pot

THIS!!! I REALLY wish I had done that. I was thinking about doing it, but then forgot by the time we poured. I regret that frequently.

 

[pmiranda]

Don't forget a weather lip for the overhead door openings.
Some folks like to run air and power underfloor to work bays... assuming you can plan that now.

 

[homebuilt burner]

Sounds like you have a pretty good idea of what you are doing. Here in WI, yes, foam under the slab and 2" sounds good it keeps the floor from sweating in the spring and late summer and keeps it from getting cold in the winter (my father's shop has an inch and he wishes it was 2, no in floor heat for him). If you are thinking of a bathroom rough in read the other post about the toilet flange issue so you avoid that pitfall.

 

[pmiranda]

The other major slab issue that you want to think about up front: continuous slope? no slope? curb at the back to keep fumes out of a potential living space, water heater, furnace, etc?

 

[TwinCharged RX-7]

The lights and chain anchor are awesome ideas, definitely doing that on mine.

 

[ddawg16]

Like NutSgt said....get that conduit in underground. I ran mine up through the bottom plate. Makes the outside a lot cleaner.

My one regret was not running more conduit under the slab to other parts of the garage. I had to run wire the hardware.....drilling a lot of holes in studs.....

Even if you don't use it, PVC conduit is cheap.....and there if you want to use it.

And upsize. If you think 1" is big enough...go 1 1/4"

 

[wssix99]

The problem with in floor heat is that it has to be on all the time to maintain temperature. I stayed at a friends cabin last weekend, it's built on a slab with in floor heat. We got up on Friday afternoon and turned the heat on it and took until Sunday morning before it was comfortable. If you're using in floor heat you need to keep it on all the time for it to be effective, otherwise it's a waste.

Don't waste your money on foam, use that money elsewhere.

Good points. I forgot this was a pole barn. I have a highly insulated building and slab and things heat up quickly, but that may not happen here. If the walls aren't air tight, I'm not sure how much good insulating the slab would be.

I'm roughing in plumbing for a bath that may or may not ever happen, 1" water line for a future well, and 30' trough style drain in the center that will shoot out to grade per code.

Think about adding something to the floor you can pull a car in with using a chain.

^ All of these penetrations in the slab WILL cause shrinking cracks to form. Rebar will be needed to keep the slab together and even more rebar (strategically engineered and placed) will be needed to keep the cracks from becoming visible. With all these penetrations, I would definitely look at reinforcing and then epoxy coating to fill in any small cracks that happen after that.

 

[joes169]

The foam insulation w/o radiant heat is somewhat "controversial" here. Personally, I would rather stick the money into fuel than the foam under the entire floor. THat said, I would still place foam (either 2' or 4' wide) under the floor at the outside perimeter, as that's where your heat loss really is. Lastly, we install a 1/2" thermal break around the entire outside perimeter (vertical, ripped to the thickness of the floor) of every pole building, including the posts themselves, to allow the concrete room to shrink around them. For the thermal break, we generally use foil faced foam sheets, "Tuff-R", etc...