ok so im in the planning stages of my build and having a few people come out to give me some estimates for a concrete slab. what are some things to ask about and ask if they do anything I should know before time? dont need an drains of doing a heated slab I will have a 4 post lift inside. thanks again!
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Need input on concrete slab
- Thread starter Dubbydoo
- Start date
akpolaris
Well-known member
You don't say where you live but a heated slab is the only way to heat. If you do some of the work yourself it isn't that tough.
bad_idea
Well-known member
Just had mine poured.
Foundation type - monolithic or block?
Slab thickness - 4" minimum, for a lift I suggest 6" (cost an extra $1100 for my 30x40) - guaranteed to be thick enough for a lift.
Surface finish? - I had him finish mine smooth, may be an issue in snow country - slick floor. I don't have snow here.
Slope? - Had mine poured flat and level. (Again, no snow melt) Will make laying out weld projects easier to square up, building benches, installing lift, etc.
How will they be accessing the garage location? Concrete truck will crack an existing driveway. My guy dumped a load of sand in the ditch and ran the trucks across the lawn. Has been dry lately, so the trucks didn't hurt the lawn.
Foundation type - monolithic or block?
Slab thickness - 4" minimum, for a lift I suggest 6" (cost an extra $1100 for my 30x40) - guaranteed to be thick enough for a lift.
Surface finish? - I had him finish mine smooth, may be an issue in snow country - slick floor. I don't have snow here.
Slope? - Had mine poured flat and level. (Again, no snow melt) Will make laying out weld projects easier to square up, building benches, installing lift, etc.
How will they be accessing the garage location? Concrete truck will crack an existing driveway. My guy dumped a load of sand in the ditch and ran the trucks across the lawn. Has been dry lately, so the trucks didn't hurt the lawn.
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Kaizen
Well-known member
Six inch thick. 4K psi. Finished smooth. I did dead flat. Only need slope for daily drivers in snow country. Also what kind of joints will he do and how big.
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I'm in the same position. 36x60 is going up next week. I'm doing 6 inch 3500psi. I'm thinking of doing the first third sloped, then the rest flat. That way I can pull the tractor or snowblower in after clearing snow and have it drain out. My two garage doors are going on the 36' side due to my property layout.
What bad_idea said is a good start. You should put down a vapor barrier, 10 mil plastic under the slab. I used remesh and fiber for reinforcement, that has worked well. Save yourself some money only make slab thicker where the lift is. Mine is 5in 4000 psi concrete, 10 inches where the lift is. You will need to keep the slab wet while it cures, that takes 7 days. I had a thickened edge, 12 inches wide, six inches deep. So my edge is 11 thick for 12 inches. Then you will need to have it cut, for crack control. MAKE SURE that where you are pouring the slab has been compacted.
Hollywood D
Well-known member
Definitely go with a flat slab. I didn’t and every time I roll my saws out I kick myself. I use mine to park my truck and the rest of it is a wood shop
Definitely go with a flat slab. I didn’t and every time I roll my saws out I kick myself. I use mine to park my truck and the rest of it is a wood shop
Do you think it's a bad idea to have 2/3rd's flat and 1/3 at the doors sloped? My building will be 60' long, so I figured 40' flat and 20ish' sloped. I have an attached garage at the house that the daily drivers will be parked.
rburke65
Well-known member
I vote for a flat slab, but that's me. I want my stuff to stay put. If drip water from a vehicle is an issue, install a drain....water will go down.
matt_i
Well-known member
Compact any disturbed soil with a jumping jack.
4" min crushed washed limestone, 3/4" nominal, plate compacted 2 ways.
6-10mil vapor barrier.
I like 4" minimum (which is NOT 3-1/2" formed by a 2x4), my opinion is to put actual steel wire mesh mats or rebars in it. Extra reinforcement at any "inside corners". 4ksi mix. I like flat, verify screeding with a rotary laser level as its placed.
Moist cure or curing sealer - applied as soon as it can be walked on.
Saw cut the control joints the next morning after the pour. 10' to 12' squares.
4" min crushed washed limestone, 3/4" nominal, plate compacted 2 ways.
6-10mil vapor barrier.
I like 4" minimum (which is NOT 3-1/2" formed by a 2x4), my opinion is to put actual steel wire mesh mats or rebars in it. Extra reinforcement at any "inside corners". 4ksi mix. I like flat, verify screeding with a rotary laser level as its placed.
Moist cure or curing sealer - applied as soon as it can be walked on.
Saw cut the control joints the next morning after the pour. 10' to 12' squares.
nmk_61802
Well-known member
Just had mine poured.
Foundation type - monolithic or block?
Slab thickness - 4" minimum, for a lift I suggest 6" (cost an extra $1100 for my 30x40) - guaranteed to be thick enough for a lift.
Surface finish? - I had him finish mine smooth, may be an issue in snow country - slick floor. I don't have snow here.
Slope? - Had mine poured flat and level. (Again, no snow melt) Will make laying out weld projects easier to square up, building benches, installing lift, etc.
How will they be accessing the garage location? Concrete truck will crack an existing driveway. My guy dumped a load of sand in the ditch and ran the trucks across the lawn. Has been dry lately, so the trucks didn't hurt the lawn.
Also if you care, make sure they are not to rinse the truck out on your property, and any overage left in the truck is not to be dumped on your property.
maxpower_hd
Well-known member
Do you think it's a bad idea to have 2/3rd's flat and 1/3 at the doors sloped? My building will be 60' long, so I figured 40' flat and 20ish' sloped. I have an attached garage at the house that the daily drivers will be parked.
It depends on what you are going to use that part of the shop for. I don't think it would be a BAD idea. But, if you plan on installing a welding table or something at that part of the shop then it may make it more difficult to level.
Mine is sloped and I like it. I do, as others have said, have to account for the slope when putting in benches and so forth. But it really isn't a big deal. I also don't have an issue with things just rolling around since most of my stuff has locking wheels. But I do have to sort of chock my welding cart. Those wheels don't lock.
But I wash my motorcycles, car engine bays, etc. Plus I have snow melt in the winter and the water flows right out the door.
Hollywood D
Well-known member
Do you think it's a bad idea to have 2/3rd's flat and 1/3 at the doors sloped? My building will be 60' long, so I figured 40' flat and 20ish' sloped. I have an attached garage at the house that the daily drivers will be parked.
I don’t think so. A full size truck is around 20-23 feet long so if you have 20’ sloped for water run off I don’t think it would be an issue unless you’re going to use that 20’ for something else.
James-W
Well-known member
I agree if you heat the space all the time then in-floor heat is really good. On the other hand, if you only heat the space occasionally when you are working out there, a heated slab will take a very long time to get the space warm.You don't say where you live but a heated slab is the only way to heat. If you do some of the work yourself it isn't that tough.
It depends on what you are going to use that part of the shop for. I don't think it would be a BAD idea. But, if you plan on installing a welding table or something at that part of the shop then it may make it more difficult to level.
Mine is sloped and I like it. I do, as others have said, have to account for the slope when putting in benches and so forth. But it really isn't a big deal. I also don't have an issue with things just rolling around since most of my stuff has locking wheels. But I do have to sort of chock my welding cart. Those wheels don't lock.
But I wash my motorcycles, car engine bays, etc. Plus I have snow melt in the winter and the water flows right out the door.
Thanks, I'm hoping to have the workshop area in the back 40'. That would include anything on rollers. I figured the front 20' would be reserved for things that currently run and drive, tractors, spare truck, etc.
Kaizen
Well-known member
Do you think it's a bad idea to have 2/3rd's flat and 1/3 at the doors sloped? My building will be 60' long, so I figured 40' flat and 20ish' sloped. I have an attached garage at the house that the daily drivers will be parked.
The 20ish will need to go out sideways. Can’t go out the 60 side as not easy to blend them. I’d go one or the other.
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Kaizen
Well-known member
Also if you care, make sure they are not to rinse the truck out on your property, and any overage left in the truck is not to be dumped on your property.
Definitely
I still have a huge piece of concrete that a sledge hammer won’t even dent. Gotta go get a jack hammer to get rid of it.
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The 20ish will need to go out sideways. Can’t go out the 60 side as not easy to blend them. I’d go one or the other.
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Due to my property layout I'm putting two 10x10 doors on the 36' side.
wow thanks alot for all the info sorry I should have stated I live in central Va doesnt get that cold here some times in the teens but im currently in a 17,000 sqf warehouse and wanting to move my stuff home I use a torpedo heater in the cold days where im working keeps the chill off. 99% sure im just gonna go with a flat slab no need for a slop to it. got just a packed gravel driveway so not worried about trucks backing in.
6768rogues
Banned
I wouldn't want a heated slab. I thought about it for a while, but gave up on the idea. First, it is too expensive. You need a boiler ($3000), which takes up floor space. A hanging furnace is a fraction of the price ($750) and takes up zero floor space. Boiler repairs are expensive and an emergency if freezing might occur. A hanging furnace is cheap to buy and cheap to repair or replace. A boiler system takes a long time to raise the temperature of the space. A hanging furnace takes about 15 minutes to raise the temperature. A hanging furnace failure will not result in a frozen and broken heating system. A boiler is subject to physical damage, a hanging furnace is up out of harm's way. I built my shop 25 years ago. Since then our kids grew up and we retired, going to FL for the winter. I can be in FL without worrying about a boiler failure resulting in a frozen, broken, ruined system that will cost plenty to fix. I turn off my water supply when I go to FL so that if something goes wrong, it will not fill the building with water. With a boiler, you have to keep your makeup water source turned on. You could use a glycol system, but it means more equipment and more money. Not me, I would not take a hydronic heating system if you gave it to me for free.
My son has a building with a water based heating system. It broke and was not noticed during cold weather. Pipes broke, the boiler froze, the place flooded, almost everything was ruined. The insurance paid dearly, but we are still trying to get the place back up to speed a year later. No, thank you.
My son has a building with a water based heating system. It broke and was not noticed during cold weather. Pipes broke, the boiler froze, the place flooded, almost everything was ruined. The insurance paid dearly, but we are still trying to get the place back up to speed a year later. No, thank you.
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ConCretin
Well-known member
I'm not sure a heated slab makes sense in your part of the country. They react slowly and are better at maintaining constant heat over time. They work great up here but I would think you'd be better of with a hot air system that reacts more quickly.
The same is true of floor drains. We often pull into a garage with a car covered by ice and snow, which proceeds to melt everywhere. Floor drains are very helpful in this situation but I'm not sure you'd benefit that much.
Give my Guide to Floor Slabs a read for some additional thoughts on the subject
The same is true of floor drains. We often pull into a garage with a car covered by ice and snow, which proceeds to melt everywhere. Floor drains are very helpful in this situation but I'm not sure you'd benefit that much.
Give my Guide to Floor Slabs a read for some additional thoughts on the subject