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OT- Water under the garage doors

William462

Cast Iron
Joined
Oct 5, 2006
Location
Delaware
I have three 10 foot wide garage doors in my shop, and in heavy rains water creeps under the doors onto the floor. After years of irritation, I'm determined to stop this problem. The floors are flat, extend about a foot outside the door, and have no ledge to keep water out. The flexible seals on the bottoms of the doors are old, and do need replacement. In addition to replacing the door seals, I'm considering installing a water dam in back of the doors; perhaps a strip of aluminum flat stock, 3/16 inch thick and an inch or two wide, atached to the concrete floor with a marine grade silicone sealant/adhesive. The issue , of course, is keeping the dam low enough so that it's not a tripping hazzard, or a major impediment to taking items in and out of the shop, often on wheeled dollies. Do you have any recommendations on types of door seals, water dams, or other solutions ?
 
With no pitch downwards beyond the concrete, you are in a possible no win situation. Look for the foam (really soft door seals), they will seal the bottoms of the doors really well and prevent water from creeping under the doors. Problem is water will pool in front of doors and when opened roll into shop area. Keep a floor squeeze by the doors and when doors are opened quickly push the standing water back. A saw cut parallel to concrete building slab across front will help stop pooling water.
 
in the uk ...they have sort of troughs in front of the garage doors that run the whole length of the door

they are place a few inches in front of the door on the outside

they are usually fitted with cast iron griddles over the top of them ...
and drain into soak-aways ..consistiig of large gravel chippings.

all the best.Markj
 
We had the same problem at a couple doors in our shop. Made thresholds using 1x6 treated pine, beveled on a tablesaw on both edges down to about 3/8 thick. Used some urethane or silicone calk underneath, and screwed them down with tapcons about 2ft on center. Tried using just the sealant for holding them first, but changes in temp and humidity, plus being driven across with a forklift having small hard tires, knocked them loose pretty quick. Reinstalled adding the screws and they've been in place several years with no problems.
 
Cut/grind a very narrow slit directly under the door. The will channel the water away. Hard to seal concrete without some sort of finish as it is naturally porous.

If you have an epoxy finish, then a very wide, soft poly-X type seal should work.
 
Home Depot has the seals in a roll.You didn't say how the doors open,if it's out put the seals out to act as a sweep.From your description seems like an awning of some sort would fix the problem.If the rain hits a wall it runs straight down and then under.My shop has the same problem--I found one of the old fiberglass TV receiver discs 10' in diameter & took it apart to mount 1/2 of it like an awning.Decorative an cheap,it even has a drip edge gutter built into it.

Dave
 
I had the same problem. I bought a product called Storm Shield.
Worked perfect for me. One tip; Get a extra tube of adhesive as they don't give you enough. I like the LockTite brand construction adhesive, it has some serious initial tackup.
 
We had the same issue. We had the contractor put a concrete buffer (a triangle if you look from the side) under the door. The door now comes down on top of the triangle and water goes elseware.
 
Do you have a roof edge near the doors?

I had a similar problem and the roof had no gutter which dumped all the water 15" from the door on the slab, or even on the doors with wind. A roof gutter solved 95% of the problem, new seals will take care of the rest.
 
Mine did the same. I used a walmonized 2x4 and ripped one side at an angle, mounted it on the floor right against the door with tapcons and silicone, then took a strip of rubber seal (looks like generic fender flares for offroaders) and mounted that to the door so it overlapped the wood, that way the wood keeps water from flowing in, and the rubber keeps water from flowing down the door and behind the wood.

Ken.
 
I used a 1/4"x1" steel flat screwed down with Tapcon screws in front of my garage door.Put a bead of silicone on each side.Then split a garden hose which fits on the steel flat.Just remove the garden hose when you have to roll something out.
 
I second the storm shield. I used that on my shop, and now, the only time water gets in when something like hurricane hugo goes through. I had to add sides on it though that went to the wall.
 
Where are you guys actually placing your seal? Directly under the garage door (which will not allow the door to lower as much), against the bottom of the door on the outside, or against it on the inside??
 
My driveway slopes TOWARDS my garage.
I had to build a small concrete dam right behind my garage door to keep the rain water out.
I made it about 1 inch tall, and 4 inches wide.
It works great.
 
I had a garage that had a driveway that sloped into the garage as well. I used to get some major flooding in my garage as a result. I took some 2 x 4 pressure treat, beveled it on both sides leaving a 1/2" top on the 3.5 side. Creating in effect a berm. Hit it with Thompsons water seal for two coats as well to prevent the swelling, UV damage and such that may occur, then screwed it into the driveway about 1 inch in front of the door - driveway side- with many 1/4" concrete screws (countersunk, these were not pan heads, they were hex head and substantial) with lead "liners" like putting them in a concrete wall.

Then I sealed the bottoms to the driveway with some caulking type driveway sealer, making quite a nice bead if I say so (like doing a tub bead, but with much more stuff).I also very lightly sealed the seams between boards with this as well while putting it together.

Each year I hit it with a coat of Thompsons. They never came loose and I only had to redo the beads twice due to normal driveway expansion and contraction - and only in a couple of spots.
This served me quite well for fifteen years, I passed by the old house and the rig is still there.

I had no room for a small drain swath of slit under the door due to the grade to the door and around the drive and the fact that the entire grade of the property to the garage was right to the building for the 20 feet length I had to deal with (a 40 foot garage and barn total, done in 1905 and adapted to a garage after being a horse barn). This set up was was a necessity at the time. Howeever, I then created a drainage area in front of the entire structure away from the asphalt by rototilling the yard about 14 inches deep by three feet wide, loosing about 80 years of compacted dirt - horseshoes and other assorted neat things. I read about "Prescription turf" and drainage turf as done at the old Mile High stadium and proceeded to put down about 6 inch pea gravel, topped it with large grit sand after putting down some open screen to create a bit of a barrier, then put down about 1/2 inch top soil with another barrier (I had the help of a landscaper friend to create this work of art) then some turf from a local turf farm. This created a real great drainage area that never held standing water and it was there i drained the standing water from my driveway and barrier.

Though this sounds complicated, the garage situation I was in - I wanted the solution to last pretty much a lifetime rather that mess with it on a yearly basis. The drainage turf idea worked so well that I did it on other areas of the house where the slope (with no way to change it) went to the house. It took a full summer, this after my first winter of fighting flooding in the garage and a frozen in car and a flooded cellar, It took about three weeks the first part around the garage, I actually tried to flood the drain turf to test it, then about four weeks around the house. The result was a home that was quite resistant to flooding and more or less "self drained" for the fifteen years I was there after I did the work, and the buyers are still happy with it. The reason I mentioned it to the buyers (along with my neighbor swearing by what I had done because he used to help the person before me bail the cellar and also helped me with the solution) was because the realtor and home inspector were leary of the slope and potential problems.

Thge drain areas also never seemed to freeze up, I think due to the ability to hold snow on top and the depth of loosened dirt. However, the same area was not soupy or spongy due to the pea gravel over the loosed and moderately compacted dirt base.

The only drawback was having to water the drain out areas during summer times where we did not get rain on a weekly basis and fertilizing the areas with starter fertilizer on a yearly basis. I needed the grass to stay alive to keep the top soil sturdy

Sounds crazy and a bit obsessive compulsive, but after bailing a cellar six times in a winter and the inability to use a garage the first year I was there, doing it right paid off for years and years. It was also a bit of the engineer in me that made me this crazy about fixing it right, and I consider this my greatest "home engineering project" to this point.
 








 
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