How long does it take for in-wall moisture to evaporate?

My house is only 3 years old, but I do have a moisture problem. I live in Cyprus -Europe and although the temperatures reach 100F during summer, there is 50-70% humidity as well. During the last couple of winters it has rained a lot for our geographical position. I identified the problem in the porch tiles that were not seal proofed. This combination (lot's of rain and the unsealed grout) must have created the problem. I have two specific walls that seem to attract most of the problem but I can also see some white moisture dust coming off some ceramic tiles inside the house (the first two series).

During the last summer, I used some grout removal tools and scrabed off some grout and regrouted with water-proof grout. But I still see moisture coming off the problematic walls. I thought that the 5-6 month summer with such high temperatures would evaporate the moisture, but was I wrong? How long does it take? After asking around, I was told by an handyman that it takes years and that the only solution (surprise, surprise he's got it!) is remove the wall cement mix and use a special crystal in the new cement mix that will crystalise any water/moisture coming in after that...

I'm a bit annoyed because I had just scrabbed, filled and painted my walls only to find out that the moisture was there 2 weeks later! And the biggest problem of course is the wife (-:

Any hints/help is mostly appreciated guys...

There are two things I can think of that would certainly help your humidity problem. One would be to increase the ventilation in that room and get that heavy, wet air moving around so it's not sitting there all stagnant. You could either install a ceiling fan (or more than one, if the room is pretty huge), or go quick and easy and cheap with a box or window fan. If you with go the box/window fan thing and have a two windows in the room that face each other (1 window on one side of the room and another 1 window on the opposite side of the room), place a fan in each window to create a cross breeze and keep them going until the weather becomes less sticky. You don't need to get a big-hurricane wind going, either -- keep the fans on one of the lower settings, enough to keep the air moving about like a gentle breeze.

The second would be to get some air conditioning into the room to being the humidity down. You can't beat central air conditioning, but for a lot of people here in the US, small air conditioners that fit inside a window opening are still pretty popular. They suck up electricity like nobody's business, but people here still like 'em anyway.

AJS