We have a screened in porch with a cement pad floor that appears to be atleast 3-4" thick. For the past 6 months when it rains or the air is extremely humid, the floor will develop standing water on it and the entire pad surface appears soaked. The ground outside the pad is dry from the roof overhang. There are no cracks in the pad where water could seep up through. The flashing on the roof over the porch appears intact and no water is running down the wall onto the pad.
Has anyone seen this before? What might be causing it? Remedies?