Carpeting Wet On Concrete Slab With Terrazzo

I'd do a leak down test on the supply plumbing first

Depending how the carpet is secured to the floor, next time it is forecasted to rain lift the rug up and look at what is happening until the rain stops for a day or two. This will provide you with much more information which will make your answer much easier to find and therefore easier to determine what has to be done.

The water might be "wicking" up through a crack or newly developed small hole that was not there before. There are several possibilities but you will never know until you look at it. Also you will probably have to pull the carpet up to fix it so at this time it is not wasted energy.

Good Luck, Old Salt

Last two months. Only?

Entire floor gets wet. Because it's all carpeted? Carpet stops, wet stops?

The wet spot has to start in a single spot, or more, and spread by wicking.

Either the drainage has changed, stopped, or the floor has cracked.

You're going to have to identify where the water comes from.

Has the water table risen?

only last two months, rest of flooring is ceramic tile and there is no water anywhere else that we can find, just under the carpet

It sounds like it might be leaking in the wall and running out under the trim....pull the carpet and fold it back around the edges where it is against the walls....when it rains the leak location should become apparent, although it would seem to be a roof leak, and the location of the leak should be identified in the attic space....this still does not mean the leak is directly above, water can travel....It also may be located near a window...sometimes the window frame leaks and the water enters the wall, travels down to the floor before it shows any moisture...There could also be a pipe leaking in the wall or attic space, although you said it only appears after a rain.....or is that the only time you look? Anyway, good luck, roof leaks can be very difficult to locate....wait until you are sure it has stopped before buttoning everything up again....

the roof was replace 6 years ago. We did check the area around the windows, walls, closets - no detectable moisture in the wall or ceiling. We will check again thank you

Other then a leak it could be condensation. Average temperature here has been a little colder this winter. And it seemed that winter had gone right into summer. 80F over the weekend. I did say seems 27F this morning. If your winter has been colder then usual the ground may have not warm up enough to keep the condensate to a level that it could evaporate off. All so do you know what binder they used on the Terrazzo. If epoxy then it's impermeable to the moisture and shouldn't past thru either way unless there are cracks. The ceramic tile may be permeable and that's why it don't show.Also more open to air movement.

If it was a leak I would look for an area wetter then the rest. Pull the carpet back there. If it seems the same thru out. Pull the carpet up at a corner. Then wait and see it the moisture just beads up on the surface.

If its not condensation, which should only create a dampness, I'd suggest checking the vent stacks on the roof. I've seen three cases of leaks at a vent stack in central Florida this spring, including my home in Brevard. In each case it was a plastic boot that sun rotted. Seems 6 to 8 years is their life in Florida. If the boot around the stack is leaking, rain water can run down the pipe without wetting the walls until it hits the slab, where it will of course spread out.

It seems unlikely to me that the water is coming up from below.

I would crawl up in the attic and look for water travel across truss members and walls near the room.

If you have a ceiling fan in the room, that would be a common place for water entry.

Do you have a sliding glass door leading out to the patio? If so, that door is a possible culprit. Check top, bottom, sides, and seal between sliders.

Terrazzo over time has a tendicy to form tiny cracks in it. You may also have a failure in the water proof membrane allow the water to seep up through the concrete base up through the terrazzo to the carpet. Terrazzo is very had to reseal best bet is to remove it and replace your water proof barrier.

Not sure how much concrete work you've done but I've seen plenty of water pump through concrete onwalls and ffloors that haven't been water proofed. That's why they seal sealant for floor and walls.

We pulled the carpeting back to the wettest area and the terrazzo, the padding and the under part of the carpet was not damp. The carpet strips nor the walls nor the terrazzo or the bottom of the carpet shows any water stains or water damage. We are assuming that this is all from the humidity and are going to try running a dehumidifier to see if this issue can be resolved. The previous 6 years, the people very rarely had the windows open or the air conditioning off. These people never run the a/c nor run the ceiling fans. The dampness is only on the top of the carpeting. Will keep you updated as to whether the dehumidifier solves the problem. Thank everyone for your comments and suggestions.

Dehumidifier might do the trick. Then the problem becomes getting the water out of the condensation tray. You may have to get one with a pump. We run one all summer in the basement of our house in Minn. The tray empties into the drain, so no pump required.