Foundation/slab quotes - Questions to ask

[kert]

I'm getting ready to get quotes on my foundation and slab for my 30x60 stick-built shop near Kokomo, IN.

I have 2 smallish trees in the way, and I'm told that it will be easier to knock them over with a hoe if I don't cut them first. Once they are out of the way, i plan to deal with the wood on my own. Also have some dirt to move to level the site.

I'm told 30x60 is too big for monolithic/turn-down, which is probably fine as I'm more comfortable with a frost-line footer. I'd ask the contractor what he recommends.

I'd like to have 1-3 courses of block or equivalent concrete wall above the slab to keep my siding of the ground and give a little more height. I may consider laying block myself.

I plan to put 2" foam under the slab and 1/2" PEX in the slab for radiant heat. I will look to the contractor for what reinforcement he prefers. I plan to offer to place the foam, steel, and PEX myself if it will save me some money.

I plan to have a 4-post lift in one bay. Checked the manufacturer's requirements, and they say minimum 4" 3000PSI, so I'm thinking 5." I will make sure to know where I plan to place the lift when i layout the PEX.

Not planning for any plumbing. Septic tank is too far away and uphill.

I'm outside of the city and the county only cares about placement, so no help from the inspector. I will be getting a permit as soon as I'm sure the dirt and concrete work won't totally blow my budget.

Anything I've missed? What questions should I ask? Any recommendations on getting the best price?

 

[SiGmA_X]

With a shop that big, you may consider where you will be putting a 2 post lift down the road too. In that case, I would suggest putting in 2 4x4 pads 6" deep for the 2 poster, and avoid PEX around them. With the 4 poster, you don't -have to- bolt it down, but I would, and in that case I would also not place PEX around the post locations. I don't think you need to go thicker than 4" for a 4 poster, either.

I've heard the same regarding the trees, use the tractor to knock/pull them over/out, and then cut, and scoop the stump out.

I know nothing of the concrete questions, and also am interested in the answers.

 

[hockey88fan]

I plan to put 2" foam under the slab and 1/2" PEX in the slab for radiant heat. I will look to the contractor for what reinforcement he prefers. I plan to offer to place the foam, steel, and PEX myself if it will save me some money.

I did this myself and glad I did, saved a ton of money, just had the contractor pour and finish the concrete. Also, the 2" foam insulation is surprisingly expensive, I paid $25 per 4x8' sheet.

 

[Ben7203]

Ask for a written quote explaining their process and materials they plan to use
Ask for a few references and go see one or two
Ask if they get the job, when could they start and how long will it take?
Are you going to apply a sealer or epoxy coating?
I would give plumbing a second thought, running water and a toilet can be very useful
Since you're in the planning stages, think about heating/cooling too

Make it very clear to the contractor they do not pour any concrete till you approve the foundation. You have to make sure the forms are correct before they pour, once the concrete is down, it's really hard to tell if they have the proper footings, in the right location. Don't be shy, get out there with your own tape and double check.

 

[brownbagg]

we have done mono slab as big as 300 feet by a 1000 feet

 

[jack stand]

I agree with the OP. Get below the frost for sure, esp heating the slab. Also put at least 1" of foam against the block wall (verticaly) for a "thermal brake". The foam is expensive but well worth it, and it can never be added later. Shop it hard, the bldg. industry pretty much ***** right now and COD is king for bldg. material suppliers. Use 3500psi 'crete at min. I did as you suggested (slab prep & radiant tube) , I did mine, pc. of cake! Don't forget to loop your pex all togher and presurize it, (40 psi & install guage) monitor for 24hr. then watch it during the pour!

 

[kert]

I did this myself and glad I did, saved a ton of money, just had the contractor pour and finish the concrete. Also, the 2" foam insulation is surprisingly expensive, I paid $25 per 4x8' sheet.

Yeah, no joke on the cost of the foam. I found about half of what I need on CL for $10/sheet, but will be buying the rest retail unless I find more on CL very soon.

 

[jlckmj]

One thing I would ask is how much soil will he have to remove? and then how much fill he thinks it will take to get the slab floor up to where you want it to be.

Plus ask how much is a load of fill, and how much are his charges to compact it, and does he compact after each load or do it all at once... it should be done after each load (or two). Then check at the local gravel yard to see that his prices are within reason.

Jim

 

[blkhonda1991]

if you do wind up pouring a frost wall dont bother with block, just pour the wall as high as you need it above the slab.

 

[willymakeit]

Insulation , vapor barrier with taped joints,4'' gravel base,wiremesh and fiber in conrete.
Make sure your footing has rebar in it.
As noted there isnt a size restriction on a mono slab.
Check the soil conditions in your area for expansion rates.

 

[egads74]

Assume you will staple pex to foam. 4" does not leave a lot of room verticle when expansion joints are cut. I would also do a thermal break at garage doors and entry doors. you are insulating the sides of the slab from the wall or expect 30 percent loss there in heat. stone... vapor barrier... rebar... note wire mess on bottom is worthless... must be up...
I like where the apron steps up to the garage floor to avoid water pouring into the floor from outdoors. If you do this allow room for garage doors to sit down within.
I would also do perimeter drain at footing and gutter all to gravity downward on property.
When you dig for footing that is the time to pipe for items coming in... water/electric..

 

[kert]

Assume you will staple pex to foam. 4" does not leave a lot of room verticle when expansion joints are cut. I would also do a thermal break at garage doors and entry doors. you are insulating the sides of the slab from the wall or expect 30 percent loss there in heat. stone... vapor barrier... rebar... note wire mess on bottom is worthless... must be up...
I like where the apron steps up to the garage floor to avoid water pouring into the floor from outdoors. If you do this allow room for garage doors to sit down within.
I would also do perimeter drain at footing and gutter all to gravity downward on property.
When you dig for footing that is the time to pipe for items coming in... water/electric..

Can you explain how to do the thermal break at the door?

 

[gabeancounter]

In GA you would just dig the footers, lay rebar, call for inspection. Pour footers that afternoon. Next morning form up all the walls (2ft or 4ft high) inspection and pour concrete that afternoon. Next morning tear off forms and prep for slab -another inspection. Pour slab that afternoon. Next morning saw expansion joints. Collect check.

As said earlier no reason in the south that a slab could not be that size for a monolithic pour.

 

[kert]

we have done mono slab as big as 300 feet by a 1000 feet

Is it possible to insulate under a mono slab? I did some searching and didn't find much. I suppose the field would be no problem, but I wasn't sure about the "turn down" portion.

Still haven't called anybody. Don't like to call while I'm at work and haven't been home during business hours.

 

[K'ledgeBldr]

This is a very simplified version/explanation of a "Shallow Frost-proof Foundation":

http://www.countryplans.com/Downloads/shallowfound.pdf

It should give you adequate information as to how it is done and protected. The cost savings usually tend to be in the labor. Material can go either way depending on sources and quantities. As you'll see mono slabs can be just about any size- it's a matter of control joints and materials.

 

[Leevon]

Don't forget to have him include sawcutting, 10x10 and it should be done within 48 hours.