How flat should a garage base be?

[chris-stoke]

Hi,

Just laid a concrete base for a concrete garage, it seemed to be very flat until last night when it rained and I noticed 2mm of standing water coving just 1/3 of the base towards the back corner - telling me that that area isnt quite as flat as the rest. Is 2mm OK for the garage people to erect the garage or do I need to put down some self leveling?
.... need an answer quick as they are coming any day now!!!
HELP!!!!!!!!!

[Paul123]

I'm no expert but when I laid the base for my garage I'm sure it wasn't level to 2mm. I would have thought it would be easy enough to lose that difference in the muck laid for the first row or two of blocks.
As an aside, if you're worried about any water that gets in puddling at the back of the garage, it might be a good idea to screed the floor. Not only will this level the floor but it makes manouvring a jack or crawler board under the car so much easier.

[chris-stoke]

Hi,

Its one of these concrete section garages, apparantly everythings gotta be very flat or else the panels dont line up properly, - and the installers walk away and bill you £100 for wasting their time, (nice!) however there must be a degree of adjustment built into the design as I'm sure (I hope!) that not every base laid is absolutly 100% perfectly flat...??!

[Tony McC]

2mm is no problem at all for a sectional garage, you'll be glad to hear.

The sections can be 'packed' to accommodate minor variation in surface level, and then the base of each section is sealed with mastic to precent any future water ingress.

[chris-stoke]

yessssssssssss! thanks for that, now I can relax finally!