I’m not really sure where to put this, but figured here was as good as any- I’m going to try to have my shop/garage floor poured this year. 36x36 with compacted crushed stone, XPS foam and radiant heat tubing under the concrete. My questions are, for shop use that will see mini excavators, CTL, tractors, etc on it, should I spec 4” reinforced concrete or 6” reinforced concrete? Once cured, should I pay to have the floor epoxy coated? I like the look of epoxy floors and the ease of cleaning spills but I question the durability. Anyone have long term experience with a particular epoxy coating? Other option is a concrete sealant, which is often used around here due to the salt dripping off vehicles and damaging the concrete. Any other suggestions or wish-I-would-haves for concrete floors are welcome. Thanks!
If I was pouring a serious shop floor, it would be a minimum of 6" thick and rebar, not wire mesh. I would also want a minimum of a 4,000psi mix. It wouldn't be epoxy coated, because I use a torch and welder in my shop.
If it were mine I would do 6" stone and 6" concrete with #4 rebar on a 4x4 grid with 9 wire mesh on top. Reinforcement is cheap up front. Your slab is small so the cost to upsize is not a huge difference up front but pays off in the long run. The rebar will take the deflections and the mesh will hold it together. Here in AL we don't have to worry about salt so no comment on that topic. Just prep'd a HD concrete parking area for an amphitheater we are working on where the tour buses will be parking. Spec is 6" DGB base, #4 on a 2x2 grid and 6" of 4K concrete.
You may want to consider having multiple 4 inch drains to be able to have whatever you wash down to drain out of shop. And, You can not have to much light.
This ain't the quote, but it goes something like- concrete work has three guarantees- 1. Theft resistant 2. Grey and heavy 3. Gonna crack somewhere
I'd go with 6" of 4500 psi, 1/2" bar on 2' centers. Skip the wire, its never where it belongs. And spend the money on plenty of chairs for the rebar. The 4500 psi isn't for the strength of the floor, but to make the floor strong enough that every little dropped piece of steel doesn't chip the floor. You need to talk to the concrete plants in your area. Concrete depends on local aggregate quality, if they have to truck in quality aggregate prices get even more stupid than they already are. Compromises may be necessary. Every other portion of your building can be upgraded at some later time. But to upgrade the floor its easiest to build another building. Don't skip the site prep. Concrete is nothing but a rug. A hard surfaced rug, but still a rug. The subgrade must be sufficient for the loading, and uniform in compaction.
For mine I did 1/2" rebar on 1' grid, I think 6" with 12" thickened edges (except the left side which is sitting directly on top of a block wall). I believe it is 3500 psi. I wish I'd gotten my act together to do it earlier in the year. It was Oct 31st and too cold to put a sealer on it. I ended up just using it and it got too dirty to seal so I just never did it. It has spalled where the salt drips off my plow truck... Other areas have held up fine.
Early in my career, long ago, I did ASTM Certified concrete testing on a regular basis. Go 6" with rebar as mentioned above. They will want to pour your floor very "wet", or high slump. That is bad for cracking and strength, but likely necessary with your heating tube system strung all through the floor. Therefore, I would go with 5000# test strength on the concrete, due to the high water content it will have. You really would like to have a 3"-4_" slump test, but in reality I bet you will get 6"-8".
^This. Floor drains, forgot about floor drains. Wire mesh stays where it's needed if it's on top of the rebar that's on chairs.
I did 3500# with fiber, 6" thick, no metal. I do not have large equipment on it though, only passenger cars and trucks. I used Rust Oleum 2 part epoxy on my auto shop floor 15 years ago. It held up great. It wore away under the front of my primary lift from abrasion over time but never lifted, peeled, or had problems from heat or chemicals. I was quite pleased. I put the same down in my new shop and have no problems. The new shop gets light use and is only 4 or 5 years old though. Yes on the light. I have 28 eight foot LED strips on the ceiling of my 36' x 84' shop with 14' walls. They are the 5k I believe (quite white vs. yellowish/soft color). They provide a lot of light but I still have more of the strips on the bottom side of some shelves over my bench tops. I am old and need lots of light. I did 5 1/2 inches of spray foam and then put 3/4" R-Max foam board over the top of it. Two 3 ton mini splits keep it 68 degrees inside year round here in FL and use very little electric. I would guess $100/mo.
Wow, too much stuff in it
Keep the suggestions coming, I really appreciate it. Unfortunately, NH (where I live) regulates floor drains. Officially, they have to be piped through a grease trap and into an approved septic/stormwater management field. Unofficially…. Well, concrete them over before you sell the house. The workaround called out on my prints is to have the slab pitched towards each of the overhead doors….
Ok, so this brings up a good question. I have 12.5’ ceilings in this garage/shop and I’ve thought about installing a car lift in the future. What prep should I include in the floor for that now? Strip footings below the floor and omit the XPS in those locations?
Most if not all car lifts 12,000# or less only require 4" slab under them, no footers or extra concrete. Check with a lift mfg on a unit you think you would buy to be sure.
Ive done 3 shop floors for myself over the years. 6" thick, #4 bar on a 12" grid has worked well for me. Ive never considered sealing as i do a lot of burning and welding. Ive got 10 years on my current shop .Theres a few divots in the floor ,but its a shop. Its stood well to every thing i do ,Had tracks from my mini excavator to crawler cranes and a D8 run on it. The base is the key ,I know you have that part dialed.
That sucks on the floor drains.
It really does! Especially since a lot of snow/ice/slush comes in on the cars in the winter. My last house had a garage with the floor dead level. I’d be pushing water out of there with a floor broom after every snowstorm.
I can understand an oil/water separator for a commercial auto/tire/repair shop floor drain(s) but residential is a little overboard.
I don't care for floor drains myself. I don't want a tapered floor that runs to the drains, because its hard to build items on the floor. If the floor is level, its easy to build square items on it, if its tapered multiple directions, nothing you build is square when done. Also, I don't want a oil/antifreeze fluid spill pouring into the floor drain. I want to clean it up where it is. Its really hateful when that special bolt rolls right down between the grates of the drain. I used to do a lot of work in a shop that had a center drain. As far as the lift goes, put footers where it may go. And make sure you know where the lines are, and give yourself plenty of space. Hammer drill in a anchor for the lift, and hit one of your in floor heat lines is going to make for a great day.
I did not really catch what this slab is for basic storage or a working shop. If it's a working shop here is some ideas I have poured a lot of concrete and built a lot of slabs. I have seen and been around so many pours that went badly due to poor planning. I have seen entire pours 7" thick, 40,000 sq ft, crack due too improper retarder being used. I have also seen slab ruined because the base was not same through out the slab. Hard and soft areas can ruin the pour later. I would consider where you need power at on the floor and run it under the Slab. I would consider my compressor location, lathe / mill locations and Welder locations for power and air piping. I don't think gravel does much of anything if your base material is hard and compacted. Installing metal weld plates on the floor are a consideration for pushing and pulling operations. These can require a "pre pour". Doing all the wire and rebar will require a pump either line or boom. My favorite shop, i have seen had a 2 leveled pour. If you have some slopeing grounds to allow it. Basically you pour a retaining wall and a lower floor say on the back side of the shop. Then you have a few steel beams that you can drive onto that are main floor level, out onto the lower floor area. You can access under a truck or equipment from the lower level and also have a lower side roll up door for a lower side entry and another work bay down there. It was great for working on big rigs.. a poured set of stairs went to the lower level and they had a full set of tools and benches down there for engine and transmission work. Spilt floor designed work area. No pit needed I have also seen steel runners in slabs for metal tracked equipment. Not sure what to tell you on the concrete specs, i have had conflicting things told to me and all the better pours are done at night. Too expensive for a basic pad. The concrete we are going to start a new large project with now requires a license to pour it. It is some crazy neat stuff. On basic concrete one set of engineers made me use 3000 psi for slower cure time and less cracking. A good cool day with mist in the air is probably the best you could hope to pour on. a lot of job site surface prep is done to allow construction to continue through wet site conditions. Gravel and soil cement being two things that can allow a jobsite to carry on faster through the wet times, when time is big money. I would never use gravel unless my dirt was poor. It all depends upon your soils and what you are building on.. a loaded dump truck doing a pre compaction test will answer your questions about your soil weight bearing capacity. A truck load of concrete is not too much terribly higher in cost than gravel so why would you put GAB down when the slab could be 10"s thick. A local cat yard here had double rebar with 12" thick isolated slabs for just the parking lot. 1.75 metal dowels tying sections together. After pour, I would definitely green saw cut my 36 x 36 slab and put my cuts based on how my work areas laid out as equally as possible. Getting your drainage right and grading right is just as important as the concrete keeping a dry base under the slab will pay for itself over and over
Get several opinions on the radiant floor heating. Some swear by it, others curse it. If you're doing a lot of work close to the floor or on a creeper it can become a sweatbox.
What is the concrete that requires a license? Any links?
This is going to sound like bs, but I am not sure i am allowed to say. Let me ask our gc and I will let you know. It is such a big deal that I am being told i will work under the licensed finishers instead of for who normally does the pours
6" is plenty. I used Heat sheet R10 and it makes the hydronic installation quick and easy, no bending over with a bunch of zip ties. The reinforcing mat goes over the top and gives the tubing even further protection. The R10 heavy also satisfies the vapor barrier requirements.
Just read this and agree with CO, floor drains suck in a shop. Never fails grates are in the way, not level for building anything, plus a real pain in the *** with a transmission jack, always creeping away. * Floor drains belong in milk barns--shop floors, use a squeegee.
Interesting point, a friend built a very nice garage with radiant heat. He loves the warm garage and hates the radiant. According to him, his cars rusted faster when parked in the garage with radiant (not sure if I believe that…). Fact is, I’m not sure I want to pay the propane bill to heat this size area with radiant. But, it costs very little for me to put the tubing in now, even if I don’t connect it into the heating system right away.
Its hard to believe there isn't more info about floor heat that a guy can really trust . I will probably be building a shop in the next few years and wish I could really trust what I have heard but I have heard so much good and bad ???
Most of you guys don't deal with as many months of cold as us guys up in Canada but I personally would never build a shop without floor heat pipes in it. The shop on the property I bought doesn't have them and while I can get the air in the shop uncomfortably warm the air near the floor and the floor is always cold. Also if you get your concrete warm the recovery time after opening the door is generally much faster than a air heater
When you look at the radiant floor heating from an engineering standpoint, the concrete floor is a big heat sink. It will take a longer period of time to bring the concrete up to temperature from cold but once it has achieved temperature it will hold it steady for a longer period of time than forced air heat. I haven't worked regularly in a shop that has it but I'd guess you probably need to leave the heat turned on to the desired temperature 24/7 to keep the work area warm. Each heat system has its pros and cons, what works best for you will depend on how the shop is used.
Ya'll must have some cheap concrete over in GA. A 25 ton load of #57's delivered runs around $32 a ton or $800 per load. 9 yard load of concrete delivered is around $150 per CY or $1350. Personally I want at least 4" of stone under a slab. Pretty much every geotech report I read the engineers spec a stone base under the building slab.
I always consider a main shop area to be middle ground on the heat scale. If it is cold out, 50 F seems pretty nice IMO. I'd love a warm floor to get that. In my perfect world I would have a drop ceiling area with a loft above that I could warm up to office-like temperatures, located inside the shop. Keep my woodworking tools warm and dry and a place to retreat to and warm all the way up if needed.
And that's the negative of only having floor heat. I currently only heat my shop a couple days a winter so a forced air furnace works much better than floor heat. But because the previous owner didn't put in pipes I can't heat the concrete if I want fulltime heat so that's why I personally don't think I'd pour a pad without pipes even if I planned on a different heat source
the pipes are really hard to wiggle in there later.
I can understand that. I was thinking OP's garage/shop is the one attached to the house he has been building so not a heavy equipment repair shop. Last 2 houses I built had drains in the garage floor with hot and cold running water spigots. It was great for hosing down the dust, debris and cob webs that accumulate in addition to washing cars in the winter. The walls were painted with eggshell paint to shed water.
Your concrete pricing is better as is the gravel. In Savanahha they are 1500 per truck almost for gravel hauling it 2 hours away from macon. Gravel under a slab is personal preference. A 36 x 36 slab with basic grading is 20k to 23k ish around here. Most only go 4"s and they don't have the extra funds to do all that fancy stuff. The only slabs we sell that are upgraded are to those guys that know what they are after. On the opposite end of the spectrum on the commercial we went over 250 yards on 5 pours . Luckily the grades were checked and re-checked and completely approved. Some slight settling was going on or the plant was shorting the trucks. This building is 700,00 sq ft that was lifted 10' and soil cemented at 65 lbs per square foot. Some of it was done 3 times. Notice no gravel. Unfortunately it has been fine graded 4 times. Rain, snow, wind erosion, pipe crews, soft spots are taking a toll. Had to hold off on several pours because of 20 to 30 mph winds, they can't risk it cracking. For say the new car plant which is 3 million square ft, it takes 10 times that amount in support warehousing. So they are building 30 million square ft in additional buildings off the main site. Everyone hears of the tax breaks they get on the main development, most all the support buildings pay it so that's where the government makes their money.
That's expensive. Is that for a tandem load or tractor trailer dump? How many tons? We can run tri-axles here and net 25 ton on payload. I am in the middle of limestone country with a quarries all over the place that make cement, calcium and gravel. Even then it's around $30 a ton delivered. Not here. One will not get a passing underslab inspection if you don't have at least 4" of gravel under the slab or an engineer's stamp saying you don't need it.
I’ve always done 6 on my stuff just because I do from time to time have heavy heavy stuff to deal with.
As a company, we used to install concrete slabs, but I remove old concrete slabs all the time. You don't say if the slab is supported on the sides with a foundation (as is the foundation is poured first, then the slab poured), or is just a slab on the ground. Concrete is heavy, and if you are driving in equipment over 5 tons, I would excavate down your grade and compact in at least 6" of gravel base over geotextile unless your area is super dry and you have rocky ground. Then I would pour 4-6" of concrete. Mesh only helps after the concrete cracks to keep it together a bit. I would do rebar in the Corners and thicker concrete if the slab is on the edge of hillside. I would also do rebar and thick concrete on the easement. I don't think the rebar is going to add much in the middle with good base, and if you ever want to get into the concrete slab later (to trench in a water line, electric hook up for a machine not next to a wall, etc), than cutting through and breaking out more than 4" of concrete with rebar ( Note: hot saw with 14; blade only cuts 3.5 can be a real pain. Lastly you don't want rain water going under the slab, so make sure you have good grade sloping away from the exterior perimeter, and gutter drains just don't go to open next to the building.
What I have learned over the years: 1) Thermal breaks around the perimeter and thermal insulation under the concrete - I wish I knew this when I had my shop built. By mid winter, my floor is freezing cold and why I keep a heating pad under my desk just for my feet during tax prep time. During late summer heat, that concrete stays warm well into the fall and the AC runs more than I would like. You need to isolate your floors from outside conditions with good insulation. A customer from Wisconsin once told me that he had a large pit under his pour, filled with boulders and a coolant mix. It was a hydrothermal heating system that he claimed was efficient throughout the severe winters. I have not heard of anyone else using that method but it sounded interesting from a heat efficiency standpoint. 2) Vibratory compaction or other proper means - make sure it is done the right way. I let the dozer operator tell me his dozer packed the gravel well enough when my pad was built up. The number of cracks don't lie but he sure did. It was an expensive lesson for a green kid to learn many years ago. 3) Sealer - best thing I ever did for my shop floors. I had that applied while the concrete was still green. Floors sweep up easy, less dust but very slippery when wet so be careful of this point. Welding above it is not a problem. Concrete does not seem to chip as bad when impacts happen but that could also be the fiber. 4) Fiber - I had that added to the mix and the concrete never chips out very bad. That never stopped the severe cracks from the lack of compaction but it does not chip as easily as my father's shop floor has that did not have fiber added. I wish that I had tons of rebar added as has been suggested on other posts on this thread. 5) If you plan to work on heavy tracked equipment, bury railroad irons where the cleats will run. Top of the rails should be just a fraction above the concrete when the pour is finished. I met a farmer that had that in his shop. I would do that if I ever planned another shop for cleated track machines. Instead, I just use thin, roughcut, hardwood board to keep the cleats from marring up the concrete. Concrete and paint are very much the same. It is labor intensive and you want the finished product to last as long as possible. Pay up front for the best materials, proper preparations and best construction methods for the longest lasting value. It is cheaper in the long run to do it right the first time, even if it cost a lot more initially.
I use old conveyor belting to run tracks on. It stores out in the weather just fine when not in use.
Several products are being considered. It sounds like it is something like this. Short panels 6', small joints 1/12" , and a lot of special fibers per foot but with much less concrete thickness. .10 per ft mark up but 25 to 30 % less total concrete. Something like that. The license for this product can be obtained by the finishing crew OptiPave® | FORTA Pavement Engineering System OptiPave® by FORTA is a fiber-reinforced concrete pavement system that reduces slab thickness while maintaining performance. Cut material costs and build time. fortacorp.com This next job they are moving 25,000 yards of dirt per day. 200,000 yards of concrete for the project. This job i am on currently they are moving 4000 yards per day. 45,000 sq ft pours going every night we can. I also spoke to terracon about gravel or not. For static slabs gravel is not needed if the sub grade is good. The only benefit is it might cut back on termites. Local codes sometimes require it, but it does not do much for the cost. Roads are constantly moving so much bigger impact on that end of things. I asked them if they would put it in there own slab and the answer was no, only if we had poor soils or drainage issues.
Lol. I've read dozens of Terracon georeports that spec'd a crushed stone capillary break for all slab on grades. That section of the georeport recommending slab on grade construction is standard in pretty much every report I'v ever read. Engineers..
Yep. I have listened to engineers trying to figure out how to fix dirt issues. Two of them are on this job everyday we are pouring. I have heard it both ways. I have done it both ways. I have watched them put GAB down on good ground, just because it was speced that way. I have seen gab over and under plastic. I've seen them use crushed concrete also trying to save some money. I have seen gab put down to the tune of a 100 trucks worth, then the sub grade fall apart under it after it rained and then it all has to be mixed up and soil cemented. 100s of 1000s pissed away. You can put in all the rock you want, if the sub grade pumps with a dump truck it is no good. I stand by my proof roll comments. In my part of the world you can get into clay that is super hard. No reason to over cut it and add gravel back in. Houses get it because they can't pack the plumbing back correctly. If you design and build a foundation that does not have water issues from the start then why do you need a capillary break? Certain soils hold water, think about the Grey mud in swamps, if you can spread it out and it drys you can actually build with it. The trick to all of it is keeping the subgrade dry as you build on it. I grade small pads on a slope until the weather is clear for the pour and footings and forms are getting set. We make it shed the water off the pad. These guys spend 10s of thousands pumping these big pads and removing water from each rain event. Rock is beneficial in keeping a wet site moving foward under the construction phase. How much rock is lost to jobs when it sinks out of sight. If your building a building in bottom land that stays wet then go for some rock. I try to avoid problem construction sites and jobs at this point in the game. This sites building was elevated 10' in a swamp. Check out this borrow pit. You can add all the rock you want I would rather have an extra truck or 2 of concrete.
So, thank you to everyone who replied. I’ve been reading along and saving many helpful pieces of advice. In the meantime, I’ve gotten 4 quotes from reputable local concrete contractors, all of the companies I either have personal experience with or friends who have given them a positive reference. Remember again that I’ll be doing all of the compaction and prep work. With that said: Company A- $8500, which is for a 5” slab, fiber reinforcement only. Quote makes no mention of relief cuts. This quote includes a $1200 charge for a pump truck. Company B- $7900, 5” slab, wire and fiber reinforcement, relief cuts included. No need for pump truck. Company C- 10,500, 6” slab, 4000 psi concrete with fiber, reinforced with wire grid and #4 rebar 2’ o.c. Includes relief cuts, no pump truck needed. Company D- $7000, 6” slab, 4000 psi concrete with fiber and wire reinforcement, relief cuts included, no need for pump truck. Thoughts? I can provide further pricing breakdowns if needed. Thanks!
Well I like Company C, or D. But a question is, how tall and wide is your shop roll up door? That may tell us how big a piece of equipment your going to get in (Weight AND Width item). There was talk of a small dozer or something, is this like for 10 tons, or are you driving in full size dump trucks or something that weigh 15 tons or more? What about base prep underneath and insulation? Also the easement going into the shop so you don't have drive over a lip? How do they do C (with rebar) without a pump truck?
Good questions! Doors are 9’x9’. This is a hobby/small farm shop. The biggest items I foresee in there are a farm tractor, 16k mini excavator, or a single axle dump truck. I’m doing the subgrade prep and compaction, to include 2” xps foam. Outside apron will be hardpack to match the driveway. On quote C, there’s no mention of a pump truck but for that price I assume (my mistake probably) it’s included. This happens to be the company that did all the other concrete work for this project so they are very familiar. (And they used a pump truck for every other pour on site).
Cheapest bid is not always the cheapest cost of the project. Since company C is familiar and you (I assume) have been happy with their work they seem to be the most responsive bidder.
Well, part of the reason I got 4 quotes was a feeling that company C was starting to price themselves pretty high. I was (mostly) satisfied with their work. They were very responsive during their part of the project, helped get things off to a good start and worked through a few site issues that arose. That said, both the garage and house foundations were 1.5” out of square and the relief cuts on the basement slab were not cut square to the walls. I am considering their bid though, and they were the only ones to include rebar in their specs.
If you're doing the prep, maybe you could do rebar also. Save a lot of money by doing it yourself and end up with a stronger finished product. It's easy to cut rebar and chairs and wrap ties and then you don't have to pay them to do it.
While I have no personal experience, I have been told you don't want to crawl or lay on a concrete floor poured with fiber. Its like playing with fiberglass insulation. I like C. Price is higher, but I like bar. I would ask about higher strength concrete for floor surface durability. Let them know you will pull samples. Get cylinder molds ahead of time.
I'll let you know. I had fiber in our floor. I think a good sealing job would eliminate that issue.
if it has a good finish there isn't a problem.
I’ve thought of that, and I don’t mind doing the work to place the rebar. But, I would assume that if I add rebar it would necessitate a pump truck for the pour?
If you pull samples, you pull 3 cans each sample. Label them as to truck number. 1st sample is for you to have broken. 2nd sample is for contractor/concrete company if you don't accept the first. 3rd is for independent lab if disagreement gets serious. There is a specified number of times each sampled gets rodded with a specified diameter rod to be compliant with the specifications. Testing is at 28 days, by which time building may be half done. So you argue about it, but usually live with it.
Yes at least a line pump. 36x36 would be a lot of raking even if you can get to all 4 sides of the form with a truck. You can break one at 7 days to see how the mix is progressing strength wise.
If you have extra time on your hands, ACI-360 is the US engineering reference for concrete slabs-on-grade. A big variable is how well-compacted the earth is below your slab. If the ground settles (even a little) your slab becomes a suspended member - think bending stress. Concrete is strong in compression, but only 20% strong in tension (unless it cracks, at which point it's 0% strong in tension). The idea is to place rebar in areas of the concrete where applied loads are trying to pull the concrete apart. Interestingly, for a slab, the proper location for rebar is approximately the bottom 1/3, or top 1/3 of the slab. Dead center is least effective. You only need to do the top 1/3 or bottom 1/3 (you only do both if you're casting parking garage decks with dynamic loading) A 6" thick slab will be 3.375 times stronger in bending than a 4" thick slab. And an 8" slab will be 8.000 times stronger in bending than a 4" thick slab. Thicker is stronger - with regard to crack resistance. A 36-foot long slab will shrink about 0.216" inches when it cures. Your options are to lock it in with rebar (heavily reinforced) with no saw-cuts, or a lightly reinforced slab with saw-cuts every 12 feet. The saw cuts must be done early - the moment you can walk on it without leaving footprints is when it's ready to cut. If you wait until the next day, the damage is done - you'll have uncontrolled cracks. I have a 40x60 shop. I went with a lightly reinforced slab (a few sticks of rebar around the posts, and garage door edges). It's 8" thick, with saw-cuts approximately 12x13 foot square. No cracks anywhere (other than within the saw cuts) after 10 years - and I've had a 20 ton dozer parked on it (with 2x12 lumber under the tracks to keep from scuffing up the floor). The garage has also been through a few small earthquakes. Just remember - nobody walks out into their shop and says "I wish I didn't buy the thicker concrete floor that doesn't have a visible crack anywhere"
One other tid-bit. Your concrete cutter will thank you if you put rebar in the bottom 1/3 of the slab. . .
The reason I said multiple 04 inch drains is so they would be spaced out far enough you would not have to have much pitch or none, just something to have the liquids flow down the drain. Since the drains are regulated, it does not make much difference. Carry On.
I've had 2 shops with it and worked in another. No complaints. My floor isn't that much above room temp. Only notice it warm if something was on the floor holding heat, like a box. Water temp is 130*, but my place has **** for insulation, cheap windows and very thin garage doors (I didn't build it, working slowly on fixing it though.... time and $$$$ is all) Have worked in shops that it was 70* at standing height and below freezing on the floor. So roll under a truck and need winter gear. Work at the bench and be sweating. Worked in one shop with overhead radiant and couldn't park under it as it would scorch the paint! I had a locker sort of under 1 heater, like 20ft ceiling so not that close. It melted some hard candy and rolls of Super 33 tape i had in there! Also warm floor means the snow/water dries fairly quick. Shop i work in for work, it sometimes freezes from the floor being that cold. With temp at ~5ft 65*
Our shop at my work has ferrous fiber in the concrete. Definetly helps with the cracking and it’s wierd when a magnetic work light will stick to it If you want to keep your floors nice then yes you’ll need to do railroad ties, replaceable timbers, or use mats for steel tracks. Don’t forget the implements, cutting edges, etc those will gouge up a floor quick and most don’t think about them Compaction is a far too ignored point. All these cheap houses and buildings that get thrown up in my area don’t get compacted properly or at all. And then they wonder why they have settling problems.
If you have a 12 foot ceiling you better go higher than a 9 foot door. I think you’ll find a lot of things are higher than 9 feet. I’d go at least 10 by 12. You’d be surprised how small a 9x9 finished door looks when backing in an 8 foot trailer.
Agree on the biggest doors possible. Never fun to want to work on something that doesn’t fit in the shop. Measure your tallest and widest equipment and add some fluff space. Definitely add fiber, doesn’t cost much extra. I think the concrete fiber they use around here is polypropylene. Have it used in almost all the slabs we poured with no issues with itching. 6” minimum. Cheaper to pour 6 now then it will be later on. Prices always go up. No drains for me. Just flat and smooth so I can mop up the mess and don’t have petrol products running into my pond. Also cure time is critical. We have waited 4 weeks minimum on all slabs to drive wheel loaders or dump trucks. Not sure if it helps but I’ve watered all my slabs during the cure process. We also try to pour in the fall or when day/night temperatures are more stable with less swing. Hot dry weather seems to be no good, as well as below freezing. Humidity is good but you can be waiting around for things to setup enough to finish. That’s fine with me, because I love getting paid to stand around.
A 10 ft door is small and we have left rods out to drive trucks in and floated them in as we went. 36 isn't that wide especially if you can get around it or from sides.
Well, I finally had the floor poured this week. 6” slab, 4K psi mix with fiber and wire panels. It’s a 2% pitch towards the doors in the parking area and the level in the back for my toolbox, etc. I think it came out really good!
Nice!
Looks awesome!
Job well done.
What is the thrid picture. Almost looks like gravel?
Third pic is the compacted crushed stone under the slab. I added pics to the post in reverse chronological order as I was scrolling through my photos.
Heated floors are the ****, last shop I worked in had them. Two overhead doors wide open 15 degrees outside, close doors and 15 minutes later shop back up to temp even with frozen truck and trailer inside. Friggin awesome.
bot.
No floor heat needed here. Air conditioning is almost a must down here, especially when one gets older.
I hear ya Doc. different world down there. This summer in 98382, for example: Hottest day in June 88 July 93 August 90 a couple of times.