Garage floor internal gradient past the entrance threshold.

[epsilonGreedy]

Is a slight gradient recommend for the main internal area of a garage floor? My garage is detached and the floor will be higher than the general drive height outside.

 

In this case I am looking to understand the advantages of a slight gradient. Is it:

• Allow heavy volatile hydrocarbon gases from a car to seep out through the door aperture.
• Encourage any wind driven rain to run outside past the door.

 

[PeterW]

I’d just do it flat and put a 1:10 gradient on the front edge up to where the door will sit and use one of the rubber threshold strips under the door as they stop 90% of the problems. 

[jamiehamy]

Personally, I'd put in a gradient. Wish I had, although it would have been near impossible during build.

 

Putting a wet car in results in a nice flat puddle of water with nowhere to go. Just a small fall would allow most of it to run off. 

[epsilonGreedy]

3 hours ago, PeterW said:

I’d just do it flat and put a 1:10 gradient on the front edge up to where the door will sit... 

 

 

Ok sounds like a plan for the approach ramp. Would a 4" incline up a 1 meter wide approach ramp be typical for a garage situated higher than its main drive?

 

It would be useful if the approach ramp could be higher/wider. The reason for this is that after putting down 150mm of 2" to 4" clean hardcore last September I am satisfied the drive base is stable and above any winter deluge ponding, so if I can just finish off with a 40mm deep topping of Cotswold Chippings (10/20mm) I can save £1000 on a further 50 tons of 2" clean and my digger man to spread it with his 13 ton excavator. My feet would also appreciate this plan sooner rather than later because it is a pain in the sole to walk on lumpy hardcore all day.

 

The trouble is that plan is it leaves my main drive 200mm below the garage FFL.

[epsilonGreedy]

3 hours ago, jamiehamy said:

Personally, I'd put in a gradient. Wish I had, although it would have been near impossible during build.

 

Putting a wet car in results in a nice flat puddle of water with nowhere to go. Just a small fall would allow most of it to run off. 

 

Good point, Swmbo will park in the garage 4 day a week for the next 10 years.

[jamiehamy]

10 minutes ago, epsilonGreedy said:

 

Good point, Swmbo will park in the garage 4 day a week for the next 10 years.

But make sure it's not TOO steep in case 'someone' forgets to put the handbrake on..  

 

Whilst I don't like putting cars in a garage wet, reality dictates otherwise. After driving in snow is the worst -the amount of water once all the under arch stuff melts off is really annoying. A very slight V into the middle would be really smooth - then it all goes exactly where you want and no risk of rolling cars.

[Russell griffiths]

Why not have a drain in the middle and slope it all to the centre.