i have a house on a slab foundation. the heating ducts are clay tile and made into the slab. with heavy rains or a large melting snow the ducts fill about half full with water and of course when the furnace turns on it blows condensation all over the walls. i have already dug out and sealed the foundation which didn't help at all. does anyone know how i would go about finding where the water is coming from???? please help!!

First you need to keep water away from the house.

That means working gutters with the discharge at least 8 ft from the house.

And the ground should slope away from the house for 8ft.

If that is not enough then you need to put in a drain system around the footings and if you already have one to make sure that it is working.

I had the same problem and when I dug down I found that the end of the drain had been buried. After extend it out to daylight I have not had any more problems.