New home garage - making proper slope

[condor11]

Hi Guys,
I decided to register to get some advice.
I am building a new house and I live in Canada.
I will have an attached 3-car garage about 23' deep.
The contractors just poured our basement floor and I wasn't very happy how they were measuring the slope for drainage (to floor drain).

I want to make sure my garage floor is done right and has proper slope. I am thinking 1/4" per foot as we have lots of snow here.

What are the proper ways that good contractors use to measure garage floor slope? Do they just use a measuring tape or are there more precise means such as laser levelers? How were your garages poured if you had asked for a slope?

 

[PT Doc]

That would be 2%. I was speaking with surveyor regarding grading and he said that concrete will drain with one half of one percent. They would certify an exterior grade with that type of concrete slope. In the garage the only water is from snow melt and anything you pour on it, so anyhtning above one half percent will move water. If you plan on putting any cabinets on the sloped walls then leveling will be more of an issue.

 

[walta]

¼ inch per foot across 23 feet is 5.75 inches front to back. That is the correct slope for a sewer pipe or a parking lot.

I do not think I would be comfortable jacking up a car on that much slope.

Walta

 

[zporta]

I would go with 1%. 2% is the max I would do in a garage. But 1% is enoght to drain the water yet not enough you will really notice while working.

 

[Markomyt1]

You might also have a outside to middle slight slope to keep the water going in the right direction away from the walls.

I have an older house here in Wyoming and the garage floor is totally flat. Thinking about veneer of concrete to do this. Right now the water goes everywhere.

 

[LegacyIndustrial]

¼ inch per foot across 23 feet is 5.75 inches front to back. That is the correct slope for a sewer pipe or a parking lot.

I do not think I would be comfortable jacking up a car on that much slope.

Walta

1/4" sounds good.

 

[royalton10]

When the contractor poured my garage floor, he had the area where the door hit the concrete, about 1/4 to 1/2" to below the rest of the floor. Keeps water from running in. I have not seen it used much but I am really glad he did it that way.

 

[APEowner]

From your contractors viewpoint the slope should be whatever is specified in the plans and unless it specified with unusually tight tolerances a tape measure to make sure the high end and low end are where they're supposed to be is all that's needed.