How to prevent garage flooding regularly?

[Jen33]

Unfortunately our garage has a down hill lead in, and a lovely level concrete floor. Every time it rains water comes in under the roller doors and floods across the floor making a mess and wetting anything stored on the floor.. I did dig out a small ‘ditch’ across the entrance and put in a heavy duty plastic drain that can be driven over but it hasn’t stopped the flooding. Wondering what else I can do to stop water entering? Wondering if building up a concrete ‘hump’ just inside the roller door might work? If so, how could I do that?

[MitchellMc]

Welcome to the Bunnings Workshop community @Jen33. It's brilliant to have you join us, and many thanks for your question about preventing water from entering a garage.

Would you be able to share an image of the area so our members have a better understanding of what you are working with? That will greatly assist them in providing informed recommendations. Let me know if you need assistance uploading images.

Adding your drainage to the front of the garage was an important first step, as there needs to be a way for the water to drain from the area. I presume you've connected this drain to your stormwater, and the water freely drains away? As long as the drain is working as intended, we need to troubleshoot why you'd still be getting water in the garage. Is the water able to get around the grate? Is the water not falling into it for some reason? Is the drainage pipe not able to carry the water away fast enough, and is the drain overflowing? Is the driveway incline so steep that the water is jumping over the drain grate? Is the bottom of your garage door not sealed adequately? Is the water entering through the walls and not the door?

Did adding the drainage help at all, and how much water is now entering the garage? Adding a hump just inside could assist, but I think it's important also to work out whether the drainage you've installed can cope with the water. If not, it's likely the water will build up and flow over your hump as well. You could use a structural grout to construct the hump, or if it's only a small rise you are looking for, you could glue down some D-Line 30 x 10mm 1.8m Black And High Visibility Yellow Medium Duty Floor Cover.

Please let me know if you have any questions.

Mitchell

[Jen33]

Thanks Mitchell. 
I don’t think the drain us really doing anything. The problem seems to be that the rain hits the concrete outside the garage door between the drain and the door, plus rain actually beating against the garage door and running down. The door does not seal at all against the floor so the water just comes in underneath. I need to either work out a way to seal under the door and/or build a hump inside the door I think. I looked at that D line floor cover but I’m not sure it would be sufficient to stop the water especially once it got driven over every day. Would the structural grout actually form the hump and survive being driven over every day?

[EricL]

HI @Jen33 

I suspect that even if you managed to seal the bottom of the garage door you would still get water to puddle at the bottom of the door. This means that water will still find a way around the seal, and as soon as you open that garage door water will come in. A way must be found to redirect the water whether it comes from the top of the driveway or the garage door.

Building a hump is one way to hold off the water gathering at the bottom of the driveway. However, if you were to encounter a storm, I'm afraid your current setup will not be sufficient to handle the deluge. It would be really helpful if you could post an image of your driveway and the garage door area. This will give our members a chance to assess its condition. We might be able to offer alternatives that you've not considered. 

If you need further assistance, please let us know.

Eric