adam0872
Active member
I was wondering if there are any concrete wizards out there who happen to know if $12,000 is overblown for a 30x50 garage with a 5" thick slab ? No heating or anything special please let me know. I know nothing about concrete
Foundation Cost
- Thread starter adam0872
- Start date
cj7jeep81
Well-known member
Any footers, or just a 5" thick slab throughout?
There are footers around the perimeter I left the quote at home with those details(I am at work now) but I can update my post when I have that because I would assume that makes a different in the cost as well. They said its a "slab on grade" I think that's French for something haha
matt_i
Well-known member
Few more tidbits...what's the depth of the frost line, is this a trench foundation "monopour" vs a "3 pour" pad & stem-wall & slab, does it include vapor barrier, crushed stone base, compaction of the subgrade and stone, is there steel reinforcement of the concrete and what kind, is the stem wall higher than the slab, is a curing sealer applied, are saw cuts part of the deal, is it done in freezing weather (like right now) or wait until spring, do you have an anchor bolt plan already developed?
Until you hone in on the specs, even getting other bids is going to be tough to compare objectively.
Until you hone in on the specs, even getting other bids is going to be tough to compare objectively.
Falcon67
Well-known member
Well, my flat slab with bitty footers, no frost line, etc was $4500 in a deal-deal, so $12K in the frozen north seems around par.
WAPat
Well-known member
How many bids do you have?
TurnipTruck
Well-known member
I have a quote for a 40x60 monolithic with one trench drain and J bolts for $21k in the far frozen North.
ddawg16
Well-known member
Excluding footer, you will need 23 yards. With footers...depending on depth.....add another 10 yards or so.
Assume $1000/10 yards/truck
The ground needs to be prep'd....figure 2 guys at least 2 days...$500/day
Rebar...forms....base gravel and/or sand $500-800
Pour day....at least 3 guys.....all day. If the truck can't get to the slab....you will need a pumper....$300 for 2 hours....$100/hr after that
So....$3-4K just for concrete
$800 misc material
$2000 labor
So you're around $7k just in raw cost....contractor does not work for free.
$12k is not our of line....a 'little' high.
Anything below $10k? Someone is either real hungry or they are taking short cuts somewhere.
Make sure the quote is all inclusive. Including what happens with the excavated dirt. A 'good' contractor will usually have a note saying he is not responsible. To you, it means he knows what he is doing.
Assume $1000/10 yards/truck
The ground needs to be prep'd....figure 2 guys at least 2 days...$500/day
Rebar...forms....base gravel and/or sand $500-800
Pour day....at least 3 guys.....all day. If the truck can't get to the slab....you will need a pumper....$300 for 2 hours....$100/hr after that
So....$3-4K just for concrete
$800 misc material
$2000 labor
So you're around $7k just in raw cost....contractor does not work for free.
$12k is not our of line....a 'little' high.
Anything below $10k? Someone is either real hungry or they are taking short cuts somewhere.
Make sure the quote is all inclusive. Including what happens with the excavated dirt. A 'good' contractor will usually have a note saying he is not responsible. To you, it means he knows what he is doing.
Nighttrain
Well-known member
Really need to compare slabs with what you are getting. For instance flat work here in Austin area is going for $4-5 per sf. That's sidewalks and driveways. No footers and rebar at 18-24" on center. Slabs are $8-12 per sf. Footer down 12" with beams in my case at the 20' and 40' then down the center (40x60 garage). This was with vapor barrier and rebar #4 and #5 ? on 12" center. I thought I had a flat yard, my slab was 6" above driveway and 60' it had to come up over 24" That requires 96 yards of base material. If I remember correct I was in $9 per sf for the floor, this was about 7 years ago. Concrete has only come up to $110 per yard compared to $100 when we did the floor. So when you compare look at what you are getting. You can probably get the price of $8000 but you will not have the rebar etc in it. I would see what the building code up there recommends and follow that.
Fordman7795
Well-known member
30x56 4" slab with wire. $5200
n20junkie
Well-known member
30x50 stick build
My 5' x 8" foundation wall with a 10x20" footer was 10k
The floor was a burnished finish, 6 in thick, 5k mix with 1/2 rebar on 24" centers. 10k
My 5' x 8" foundation wall with a 10x20" footer was 10k
The floor was a burnished finish, 6 in thick, 5k mix with 1/2 rebar on 24" centers. 10k
I got bids from 8500 to 14000 for a 24 by 30 garage with 42 frost depth footers, using
wire mesh in the slab and stem wall 8 inches above slab, j bolts every 2 feet, and a center
footer from front to back. Concrete here is running close to 125 per yard.
wire mesh in the slab and stem wall 8 inches above slab, j bolts every 2 feet, and a center
footer from front to back. Concrete here is running close to 125 per yard.
glentre
Well-known member
In our area if you have footers with the 5"slab, $12k looks like a very reasonable number for that size.
Glen
Glen
ddawg16
Well-known member
the big key is the footers....how deep and how wide
For example.....a 12"w footer 2' deep.....12 yards of conrete
For example.....a 12"w footer 2' deep.....12 yards of conrete
astroracer
Well-known member
Can I ask why 5" thick? 4" is plenty for garage/shops and would save you a bit.
Mark
Mark
ard
Well-known member
adam0872.... really really need the complete specs, otherwise this is just speculation.
Contractor might not be laying mesh or rebar, and just figures an extra inch will do it.... who knows.
I thought I would take a crack at what you should provide so the experts could chime in... anyone add or delet or correct this punch list:
Specs.
Pad Dimensions: 30 x 50
Thickness: 5"
Footing depths and width: ____
Pour foundation first, then floor later?
Mesh or rebar? In foundation? in slab? Size and spacing
Any Anchors? size and spacing
Ttype of concrete mix, #sack, compressive mix, etc
site prep: fill, grade, gravel, compaction...
vapor barrier?...
Slab finish? Control joints? Saw cuts?
Contractor might not be laying mesh or rebar, and just figures an extra inch will do it.... who knows.
I thought I would take a crack at what you should provide so the experts could chime in... anyone add or delet or correct this punch list:
Specs.
Pad Dimensions: 30 x 50
Thickness: 5"
Footing depths and width: ____
Pour foundation first, then floor later?
Mesh or rebar? In foundation? in slab? Size and spacing
Any Anchors? size and spacing
Ttype of concrete mix, #sack, compressive mix, etc
site prep: fill, grade, gravel, compaction...
vapor barrier?...
Slab finish? Control joints? Saw cuts?
Assuming it's a floating grade-beam slab (substantially thickened edge with at least 2 rebar running continuous around the perimeter) your bid is cheaper than I would bid it, unless the topsoil is already removed and you need minimal gravel to level the grade out.
matt_i
Well-known member
Personally I wouldn't build a floating slab in North Dakota as describded in the quote. Too much risk of frost heave trashing it and your building on top. Either build the frost-protected shallow foundation or open up the ground and get below the 100yr frost line.
Rougly 20 yds of concrete in the flat. Roughly 6 yds of concrete in the grade beams. ($2800 WAG)
Lets just throw down $1000 for the rebar @ 24" oc and 500 for custom one-off forms (likely they'd have their own reusable or rent)
75 yds of crushed 3/4" washed stone @ $40/yd (WAG here) = $3000.
$7300 materials + 4700 labor.
Rougly 20 yds of concrete in the flat. Roughly 6 yds of concrete in the grade beams. ($2800 WAG)
Lets just throw down $1000 for the rebar @ 24" oc and 500 for custom one-off forms (likely they'd have their own reusable or rent)
75 yds of crushed 3/4" washed stone @ $40/yd (WAG here) = $3000.
$7300 materials + 4700 labor.
jimzz2006
Well-known member
What did you end up doing? I am in Iowa. Got a quote for 30x56 with frost walls rather than your thickened edges. Quote I got was 12,800 with 5" floor and 1/2" rebar every 2'