Garage floor grade!

[waterstone]

Hello,

First time poster here. Apologies in advance for the lengthy post!

I'm looking for any helpful ideas/advice you guys might be able to offer, I have searched your forum and I've seen a couple very similar questions in older threads... Figured I'd give it another shot.

Our new build home just had the garage floor poured last week, and it's very steep. It's a two car garage, and it's 21' in depth (front to back), I've gone to measure it and speak with the super with regards to it. The front is 8 and 3/4" lower then the back. From the bit of re-search I've done, this leans on the extreme side for grade.

A little more details: the Lot itself is fairly flat! Currently has one step (2 riser into the home from the garage it self, we have an exterior side entrance, that doesn't require a step, but is very close to needing a step.. The superintendent's explanation is that 8 3/4" isn't to much grade, and they normally do 5" min even for a 21' deep garage. And he also says that most home owners don't want two steps (a 3 riser) into the house, and don't want a step coming in from the exterior, "so we grade it more aggressively". I'd much prefer having to walk down a couple steps, and having a step at the side door, for a more level grade!

Any helpful suggestions would be much appreciated,

Thanks,

Jason

 

[7th Kahuna]

I've not seen anything like that. In my mind that is way extreme. As I learned it 1/4" per foot was good for draining outdoor paving, maybe a carport, and 1/8" per foot was fine for a garage. Just enough slope to clear water dripping from a car or a slow leak from a water heater or cloths washer. Sloping a garage to avoid a step seems silly. Sounds like you've got enough slope to get anything on wheels rolling. I'm not sure what you are looking for in terms of suggestions. Unless you can prove that the slope is a defect and that story the super gave you is just that, a good story, I'm not sure what your options are unless you are prepared to break out and replace the slab. Now it is possible the super gave you a story. I've heard worse.

 

[wssix99]

the Lot itself is fairly flat! Currently has one step (2 riser into the home from the garage it self, we have an exterior side entrance, that doesn't require a step, but is very close to needing a step.

The slope in the garage, along with your gas curb, (step up in the garage) is required by code. Cars can leak gas fumes, which are heavier than air and fall to the ground. If they build up in one place, they create an explosion hazard. The gas curb keeps the fumes outside the house and the slope in the garage allows them to "fall" to the doors and out of the garage. (You could make the argument that the steeper the slope, the safer.)

I researched this slope in my garage before building it and found people using anywhere from 1/8" to 3/8" of slope per foot.

I wouldn't say your slope is uncommon, but it is towards the steeper end of things.

 

[waterstone]

I've not seen anything like that. In my mind that is way extreme. As I learned it 1/4" per foot was good for draining outdoor paving, maybe a carport, and 1/8" per foot was fine for a garage. Just enough slope to clear water dripping from a car or a slow leak from a water heater or cloths washer. Sloping a garage to avoid a step seems silly. Sounds like you've got enough slope to get anything on wheels rolling. I'm not sure what you are looking for in terms of suggestions. Unless you can prove that the slope is a defect and that story the super gave you is just that, a good story, I'm not sure what your options are unless you are prepared to break out and replace the slab. Now it is possible the super gave you a story. I've heard worse.

Oh yea, anything on wheels looks like it will be rolling if not chalked..

I've found out there's no min/max code for the grade of your garage floor here in Ontario. So proving theres a defect with the install of it is going to be tuff.

 

[Zeke]

That's too much for comfortable working and installing a bench down one side but I be that's just dandy to get the water out from the melted snow you bring in. Is the glass half full?

 

[waterstone]

The slope in the garage, along with your gas curb, (step up in the garage) is required by code. Cars can leak gas fumes, which are heavier than air and fall to the ground. If they build up in one place, they create an explosion hazard. The gas curb keeps the fumes outside the house and the slope in the garage allows them to "fall" to the doors and out of the garage. (You could make the argument that the steeper the slope, the safer.)

I researched this slope in my garage before building it and found people using anywhere from 1/8" to 3/8" of slope per foot.

I wouldn't say your slope is uncommon, but it is towards the steeper end of things.

I've never seen this kind of slope in a garage of a residential home before.. See it in underground parkades often though!

 

[waterstone]

That's too much for comfortable working and installing a bench down one side but I be that's just dandy to get the water out from the melted snow you bring in. Is the glass half full?

Glass half empty in this case, we wern't planning to use the garage to park in.. That might change now though!

 

[wssix99]

I've never seen this kind of slope in a garage of a residential home before.. See it in underground parkades often though!

Yea. Most of what I've seen has either been 1/8" - 1/4". (The architects I've worked with default to 1/4" and I had to beg for 1/8.")

 

[Dakota00]

I have almost 7" of slope in a 20ft span in my garage, it's not uncommon.

 

[Gerald O]

Code says it has to be sloped but doesn't say how much. So I wrote "sloped" on the plans...then verbally told my concrete guy 1 inch across the 24 feet depth. It is just enough to show on a level.

 

[Pate]

I had mine poured almost flat in anticipation of a 4 post lift install. I guess you won't have an issue with standing water.

 

[youwish2bme]

That is WAY to much slope.. 1/4" per 4' ...

Hitch

 

[spotco2]

The superintendent's explanation is that 8 3/4" isn't to much grade, and they normally do 5" min even for a 21' deep garage. And he also says that most home owners don't want two steps (a 3 riser) into the house, and don't want a step coming in from the exterior, "so we grade it more aggressively".

What did the building plans or contract specify as the slope of the floor?

If nothing specific was stated, then you're the proud owner of a ramp in your garage

Not really much you can do if nothing was specified. Not really much you can do with the slope except rip it out and replace it or embrace the slope.