Garage Floor Effloresence

Wanted to get some thoughts from anyone else that has run into Effloresence on a garage floor. My thoughts are…While pouring the concrete the person inadvertantly moved the barrier in this particular spot and now there is moisture intrusion of a minor nature but enough to cause discoloration and the formation of effloresence. There are no pipes that I can map out that run under this area. Home is 2002 built.

Any Comments on this???


You have moisture coming up through the floor .
The only thing you can do is lower the water table.
Keep the water out from under the floor .
Lower the sump pump.
Take the out side water away from the home .
Extend the down spouts .
Paint will not help or last.

Often, concrete installers will pour a garage floor without a vapor retarder at all, thinking that the vapor retarder will slow the curing of the concrete, and that it isn’t living space. Of course this thinking isn’t right, but I’ve heard it more than once. All of the suggestions in the previous post MAY help, but they also may not. Moisture will migrate up through the concrete whether water is prsent at that elevation or not. In any case, the efflorescence is probably the result of salts contained in the concrete, and it should eventually stop, when the supply of salts is exhausted.

The majority of the garages I see, have efflorescence on their floor. It comes, not only from water tables, but also rain water and irrigation water the percolates into the surrounding soil.

Modern construction will generally include practices that will minimize efflorescence, such as vapor barriers, PT foundations, raised slabs, etc., but the general nature of garage construction lends itself to this type of moisture intrusion. Garage floors are usually at, or below the surrounding grade level, and therefore subject to moisture intrusion, regardless of the preventative measures taken.

I had looked at a new construction home a couple of years ago. There were water puddles in the garage floor, and the potential buyer said the water had been there for several weeks as he checked on the house.

That same day, the plumber came by to repair the water line from the street to the house. It had been leaking and flooded the side yard. (the other side of the house)

The water was flowing downhill from the leak on one side toward the garage on the other, and percolating up through the garage slab. Didn’t see any signs in the rest of the home.

After fixing the water line, the puddle decreased and eventually disappeared.

It also had wood showing in the foundation concrete surface.

The buyer bought it, anyway. Go figure.

A/C lines in the slab?

Good to see there’s no shortage of water in your part of the Golden State. :stuck_out_tongue:
It’s usually groundwater related as mentioned by JP. Maintain perimeter drainage.

John Kogel