How much slope on garage apron is too much?

[Notch1988]

Ground work has started on my detached garage and after doing some shots it looks like I'll have a 12" drop over a 5' apron into the back alley (20%). My property has an arc to it, so the apron is 5' on one side and 7' on the other which brings the slope down to 14% on the longer side. There are things I can do to reduce this but I'd rather not if these slopes are "do-able".

 

[Gary S]

Those slopes are definitely doable. They are likely more than ideal, but if they set you up for proper water drainage and they fit the landscape, you will be OK.
It would be far worse to have no slope or a backward slope that allows water to run into the garage.

 

[srmofo]

I have a pretty steep apron myself. Its probably 18" over a 10' span. I honestly dont think it could handle anything steeper. Sure it keeps the water out, but you're not pushing a car into it...or even my motorcycle for that matter.

If I could do it over again, I would have lowered the garage slab and used another course or block. My apron is useless, but I was stuck because of setbacks and the size of the garage.

 

[rponfick]

I see you live in Canada. Is area shaded in winter and have possible ice build up areas? That can be dicey trying to shoot up into a garage on ice.

Ralph

 

[Wingnut65]

A typical slope on concrete to maintain positive drainage is 1/4" per foot. It is shallow for getting a lot of water to drain away, but for an apron, it would work.

But, this is definitely too much slope...

 

[rponfick]

Wingnut65, with a 4 wheel drive vehicle, and living in Florida, that driveway may work. But, probably not in Canada. You may need a car lift just to get in the garage.

Thanks for sharing. Ralph.