My new garage is 18x29 deep. Concrete guy asked if I want it sloped. He said she he normally does 1/8" per foot. Would I notice that and will it be a problem for a lift? Or should just make it level or maybe slope the half of the slab near the door which is where I would park a car.
Garage slab slope.
- Thread starter dnwong
- Start date
BillK
Well-known member
Dudley,
Is this an attached or detached garage ? If it is attached to the house it might have to be sloped by code. If you are going to be parking snow covered cars in it you probably want it sloping towards the door for runoff.
On the other hand, if it is a detached garage that will mostly be used as a workshop, I would make it as flat as possible. When I built my detached 24x24 I had to almost beat the concrete guy to understand that I wanted it level. He did a real nice job and it is definitely the way to go if you are going to be working on stuff. I built two race cars in mine and it was great having everything level. Same goes with work benches, cabinets etc.
My garage that is attached to the house is sloped and I don't even have to start my Tahoe to back it out of the garage to wash it
So I would say level if at all possible.
Is this an attached or detached garage ? If it is attached to the house it might have to be sloped by code. If you are going to be parking snow covered cars in it you probably want it sloping towards the door for runoff.
On the other hand, if it is a detached garage that will mostly be used as a workshop, I would make it as flat as possible. When I built my detached 24x24 I had to almost beat the concrete guy to understand that I wanted it level. He did a real nice job and it is definitely the way to go if you are going to be working on stuff. I built two race cars in mine and it was great having everything level. Same goes with work benches, cabinets etc.
My garage that is attached to the house is sloped and I don't even have to start my Tahoe to back it out of the garage to wash it
So I would say level if at all possible.
jloehlein
Well-known member
My preference is flat, but I do alignments and corner weighting of cars. I've never really had any issues with water - I have a floor drain towards the back of the shop that I can squeegee any water into, or I just push it out the door.
Leaflessshadetree
Well-known member
I'd hate to have it so that water would run toward the back or against the walls. Slight slope towards the center or doors can ensure that that doesn't happen.
Ideally I'd want flat.
Ideally I'd want flat.
bczygan
Well-known member
Flat!
Dustball
Well-known member
For those of you who are saying "flat", that is not the same as level. That can bite you in the **** if you spec a flat slab without letting the contractor know that you desire a level slab.
Kaizen
Well-known member
Can you explain? Aren't a sloped and level slab usually both flat?
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Cyberbear
Well-known member
Originally garage floors were sloped for drainage and washing them down once and a while to get rid of flammable liquids. Also, they poured stem walls so the water wouldn't rot the mud sill. Most garages were also vented at floor level for the same reasons.
matt_i
Well-known member
1/8" per foot over 29' is about 3-1/2" out of level.
I would want the pitch if you intend to park cars in there.
But, I think I'd want around 1-1/2" over the entire length, which probably works out closer to 1/16" per foot.
I would want the pitch if you intend to park cars in there.
But, I think I'd want around 1-1/2" over the entire length, which probably works out closer to 1/16" per foot.
James-W
Well-known member
Re: Garage Slab Slope.
If the building is going to be used more for a workshop than for a garage, you want the floor to be level. If all you do is park vehicles in the building, then a slight slope toward a drain or the overhead door is the way to go.
If the building is going to be used more for a workshop than for a garage, you want the floor to be level. If all you do is park vehicles in the building, then a slight slope toward a drain or the overhead door is the way to go.
larry4406
Well-known member
In the attached and detached garages my company builds, we typically have a 3" total pitch over the depth of the garage for water runoff. Your call if you think this may cause issue with your lift. My personal garages have all been sloped and this slope is not noticeable. That said I do not have a lift and I do not have a frame jig either.
Make sure your concrete contractor DOES NOT give you a weather lip at the garage door. Instead transition thru this area with a a downward (ramped) slope. Will make it easier for you to roll jacks in and out. The weather lip does serve a purpose and that is to prevent driving rain from getting under the door when it leaks and up on to the slab. If you use the ramped detail, then it is essential that if be consistent across the opening of the door so that the door seals well. See pictures
Make sure your concrete contractor DOES NOT give you a weather lip at the garage door. Instead transition thru this area with a a downward (ramped) slope. Will make it easier for you to roll jacks in and out. The weather lip does serve a purpose and that is to prevent driving rain from getting under the door when it leaks and up on to the slab. If you use the ramped detail, then it is essential that if be consistent across the opening of the door so that the door seals well. See pictures
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ms fowler
Well-known member
Flat and level are two different things.
Think of flat as the surface of a hard cover book. It remains flat no matter how you hold the book, laying on a table, or standing up on the bookshelf, it is always flat.
Level is more like the surface of the ocean. It may show a little or a lot of local variation (waves), but overall, we consider the surface of the ocean to be level.
The old standard for concrete floors was how flat it was over a 10' straight edge. People in the concrete business came to realize that was not specific enough. Is there one single dip in that 10', or are there 20 dips--all of the same magnitude in that 10'. The man credited with writing the ASTM standard on this (ASTM E1155) was a concrete contractor. He got called in to repair problem slabs. Warehouses were experiencing problems with fork lifts that ran up and down the aisles hitting the top of the racks on both sides of the aisle. Those slabs met the old standards for ___"over 10', but failed in reality.
MushCreek
Well-known member
We have a 2" slope towards the door in a 24' long garage. I don't notice it at all, but this is a parking-only garage.
wssix99
Well-known member
No. The lift should have shims and instructions for this. (Even if you tell the contractor to make it "level," it won't be perfect. There are perfect contractors who post on this site, but its a funny thing - none of this type ever seem to show up on one's projects!) You can also level the areas only where you are going to put the posts, if you want.
If you are going to have gasoline powered equipment in the garage or cars, it should be sloped. There will be gas fumes in the area, which are heavier than air. Building code specifies (if your municipality requires you follow this code is a different thing) that these slabs be sloped to the garage doors to these heavier-than-air gases will escape to the doors. For this reason, level floors in garages are fire/explosion hazards. People won hard-fought Darwin Awards that led to this code stipulation and I hope that you never become part of that group! (Even if your concrete contractor would let you be.)
I have a 35X25 garage with a 1/8" slope and I can't notice it. I can move a 400 lb cart around with ease and it doesn't roll away. It really is very close to level - but sloped enough to deal with the gas issue.
We slope almost every floor we pour, unless it truly is a working shop, and not car/junk storage.
At depth of 29', you could probably leave the back half level and mount the lift in that half. Otherwise, you could double-nut the lift, leaving it slightly off of the floor, and use non-shrink grout under the base plates after you get it leveled out. THe grout is generally for more extreme cases though.
IMPO, 1/8" is the minimum for pitch on a floor that will see wet/snowy vehicles on a regular basis. Unless you crew is extremely diligent, you still have a chance for a few standing puddles on the floor that you may have to squegee. Because of this, we generally shoot for closer to 1" in 6' of run to ensure the water flows as we're not perfect by any stretch.........
At depth of 29', you could probably leave the back half level and mount the lift in that half. Otherwise, you could double-nut the lift, leaving it slightly off of the floor, and use non-shrink grout under the base plates after you get it leveled out. THe grout is generally for more extreme cases though.
IMPO, 1/8" is the minimum for pitch on a floor that will see wet/snowy vehicles on a regular basis. Unless you crew is extremely diligent, you still have a chance for a few standing puddles on the floor that you may have to squegee. Because of this, we generally shoot for closer to 1" in 6' of run to ensure the water flows as we're not perfect by any stretch.........
SILVERPLATE
Well-known member
I built a new home a year ago with an attached garage and elected to have no slope. My garage is 25 feet deep at an eighth of inch a foot it would be noticeable. I was also planning on and do have a four post lift. It's perfect.
jives
Well-known member
Our 32' deep garage/barn was built last year and we opted for no slope, the reason being that it also serves as a workshop and play area. We only park one car in there, and it does bring in a lot of snow and water. A sloped floor would mean that it would drain and then pool against the garage door seal. Yes, drainage grooves could be made, but that would negate some of the benefits of a tight seal.
Right now we use a 3' wide floor squeegee to push the water out after it melts off the vehicle. No problems, takes a minute. In the future we will get a mat with grooves to keep the water off the floor.
Right now we use a 3' wide floor squeegee to push the water out after it melts off the vehicle. No problems, takes a minute. In the future we will get a mat with grooves to keep the water off the floor.
ct03911
Well-known member
I had my floor poured recently. I have 3 1/2" slope over a 27' deep garage. I wanted an aggressive slope to help with water runoff because I will be washing cars frequently inside during the winter in CT. I'm using the garage as a detail shop and work shop.
Now, I'm not sure it matters a whole lot. I haven't washed a car in there yet but I have washed the floor after a few snow storms to cleanup the sand etc.
The water doesn't really seem to run out that quickly on its own anyways.
I have to squeegee the floor dry anyways.
I expected and planed to do that, but the real water runoff I anticipated doesn't happen all that much.
Two other thoughts.
I have a sealer on the floor. No epoxy paint yet. That, and the fibers in my concrete mix make for a rougher finish. It's not a super smooth look now, may never be. I feel that finish slows the water runoff a bit. I don't see that changing unless a semi-gloss epoxy ends up making it "slicker".
We'll see.
I do have a 2 post lift. It was no issue at all. The installer put in a thin shim on one side and it is barely even noticeable.
If I did it again I'd do the same thing.
I just thought I'd have more water runoff than I do.
A slope seems to me to be a good idea with little downside but even 3 1/2" over 27' won't make water just flow out as quick as I thought.
Now, I'm not sure it matters a whole lot. I haven't washed a car in there yet but I have washed the floor after a few snow storms to cleanup the sand etc.
The water doesn't really seem to run out that quickly on its own anyways.
I have to squeegee the floor dry anyways.
I expected and planed to do that, but the real water runoff I anticipated doesn't happen all that much.
Two other thoughts.
I have a sealer on the floor. No epoxy paint yet. That, and the fibers in my concrete mix make for a rougher finish. It's not a super smooth look now, may never be. I feel that finish slows the water runoff a bit. I don't see that changing unless a semi-gloss epoxy ends up making it "slicker".
We'll see.
I do have a 2 post lift. It was no issue at all. The installer put in a thin shim on one side and it is barely even noticeable.
If I did it again I'd do the same thing.
I just thought I'd have more water runoff than I do.
A slope seems to me to be a good idea with little downside but even 3 1/2" over 27' won't make water just flow out as quick as I thought.
Kevin54
MEMBER EMERITUS
I have a slope in my garage and it doesn't affect the lift at all. You can always shim the lift slightly if it is that much out of plumb.
coldh2o
Well-known member
My 24' deep garage on the house and 40' deep detached shop both slope about 1/8" per foot toward the doors. You never notice it day to day, and it definitely makes clean up easier.
Dudley,
Is this an attached or detached garage ? If it is attached to the house it might have to be sloped by code. If you are going to be parking snow covered cars in it you probably want it sloping towards the door for runoff.
On the other hand, if it is a detached garage that will mostly be used as a workshop, I would make it as flat as possible. When I built my detached 24x24 I had to almost beat the concrete guy to understand that I wanted it level. He did a real nice job and it is definitely the way to go if you are going to be working on stuff. I built two race cars in mine and it was great having everything level. Same goes with work benches, cabinets etc.
My garage that is attached to the house is sloped and I don't even have to start my Tahoe to back it out of the garage to wash it
So I would say level if at all possible.
Its an attached garage.
Dustball
Well-known member
Post #12 has a good explanation. Flatness is the characterization of how "wavy" the surface is over a certain distance. The surface can be both flat (smooth) and have a slight pitch to the overall length of it. On the other hand, a level slab can also be not flat in that it'll have slight waves over the area.
For those of you with sloped floors, are you on monolithic pours or footers and stem walls? I just spent my life savings on my dream garage and I think I made a big mistake. I had to by code build the slab on a slope, 1/8" every foot. My slab is 36' long so I have a little over a 4 inch drop from back to front. Well I choose to go with a mono pour for quickness and cost reasons. Only problem is my garage is a modular Amish built full 2 story, so it came in 2 pieces and they slapped everything together in 4 days. It's 2x6 construction with a massive 24' ft. beam and 2x10 joists, so it's solid, but the whole structure isn't level because it's on top of a sloped slab. I'm sure most of you guys who built on a sloped slab had your garages built on site and accounted for the slope. My Dad said I'm an idiot and thinks I will have problems with doors and windows shutting in the future and now I'm paranoid it could be even worse than that. Am I just freaking out and over thinking this or do you guys think I will have problems in the future? The foundation is super strong, I did 3500 psi, fiber reinforced, wire mesh and rebar in the turn down footings below the frost line, with a 5 inch slab. The garage is 28x36 true two story, so it's a beast. Your thoughts are appreciated.
MushCreek
Well-known member
You shouldn't have any problems 'down the road'. Problems arise when things change, such as settling. If it's built right, it shouldn't move. You do need to make sure that the doors are hung plumb, though, or they'll open or close on their own when you let go of the handle. The rest of the building being out of level or plumb won't affect anything unless it's enough that you can actually see it. Even then, it's just a matter of aesthetics rather than any real harm. BTW- I didn't bother accounting for the slope on our attached garage, and you can't see it. I did make sure the openings were plumb/level/square, though.
No offense, but as a professional contractor, everything you just explained is "pure hackery"and could have been avoided relatively easily.
When pouring a mono-slab with pitch to the slab, you need to pour curbs (usually formed and finished at the same time as the rest of the slab). The curbs will be perfectly level, and the balance of the slab inside is what is pitched to the OH doors.
As for the carpentry part, this is just one more of many examples of a"stigma" tied to the Amish community and construction. The "stigma" is that they are "old world craftsmen" that carry skills that are long lost on those living a more conventional lifestyle. The reality (from all of the years that I have observed) is that they are almost all complete hacks and build everything like it meant to house pigs. They are substantially cheaper for a very obvious reason, their work is often far inferior...........
n20junkie
Well-known member
My new shop is dead level.
I don't was cars, deal with snow covered cars, but I do fab, weigh, and do chassis setup. All need a level surface.
I don't was cars, deal with snow covered cars, but I do fab, weigh, and do chassis setup. All need a level surface.
Yes, I GC'd the job myself and I am far from a contractor, just handy and manage small contractor jobs as a facilities manager at a large law firm. But here in Northern VA, having a contractor build the garage (2000 sf house more like it) I just built would have been well over 100K and I did it for 70k (including a ton of electrical, a mini split HVAC system, knotty pine tongue and groove in the man cave etc.) with GCing and doing the finish work myself. Maybe you missed the part where it was a modular garage, they could not sit two halves of a 28x36 garage onto curbs, I discussed that option. The quality of the garage is absolutely perfect, couldn't find a thing wrong with it, the craftsmanship is fine. There are two exterior doors that are a little out of plumb, but if that's the only issue I have with it down the road, I'm OK with it. Not sure why you have such a problem with the Amish, I had a great experience working with them, much more so then using normal contractors from Northern VA, that's for sure. I don't have many good pictures on my work computer of my garage, none of it finished in fact, but I have attached a few, I'm pretty proud of the result for the 70k I put into it in one of the most expensive parts of the country. Anyone else have an opinion of possible issues I would have down the road? You can not see the slope in the structure, or feel it when your walking around. I'm building a custom bar in the man cave right now and the last thing I have to do is put down the hardwood floors and move the pool table in and I'm all done besides moving in all my tools down stairs and organizing. Final inspection is on Monday, wish me luck!
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dave*99
Well-known member
Keep in mind that if you are lifting low ground clearance cars with a 2 post lift these items will matter. Double nutting the lift base will raise the minimum pad height of the lift.
A sloped garage floor will cause the 2 rear lift pads to have a higher minimum height than the front pads.
These conditions may force you to drive low cars onto slabs of wood or to use a floor jack to get the lift arms to swing under the car.
Welcome to the forum
It looks awesome and what's the material on ceiling and walls
I have not really seen the timber resting on slab. Usually a level curb is poured for perimeter. Did they not really level the studs as they build it ?
Overtime make really sure the rain doesn't seep in from outside thru the slab and everything well sealed
Ign
Well-known member
This. Sloped is for soccer mom parking.
I even had a carpenter friend who built a chair in a sloped garage and then said he realized his error once he used the chair anywhere else and it leaned forward LOL
Oh and I do deal with snow-covered cars. A lot. So what? It's concrete. The water pools and evaporates. Steel building is the only way to fly anyway, so no worries about framing rotting out.
Again, the garage was modular and built off site and hauled to my house in two pieces, so they did not account for the slope while building it and placing it on to a curb would have been damn near impossible (I watched the whole nerve racking process go down)
The timber is a 6x6 pressure treated and there is flashing on the outside, not to mention I had the Amish put silicone between the 6x6 and the pad, planning on sealing the inside in the next week or two. I also had the whole area treated for termites before the pad was poured and I have a contract for termites for around the perimeter of my house and this garage as well. I have had hard down pours and no water issues what so ever. I put gravel around the entire perimeter of the garage as well which helps too.
The materials on the walls and roof of the second floor is knotty pine tongue and groove. I spent 4k on it from a lumber yard in Michigan, the estimates I was getting for finished drywall and paint were coming in higher than that so my Dad and I hung all the wood paneling ourselves which looks better in my opinion and less maintenance, plus it was a fun project.
rburke65
Well-known member
Level....you'll like it. As always, it's just my opinion.....
bczygan
Well-known member
Dead flat.