Lol, it's very possible to be condensation.
First thing i see when you pipe your aircond in the wall without any insulation, it's definitely the problem. Maybe you seen others doing it, they might also suffer the same problem as you. unless they dont use the aircond for long duration. Even with a slanted pipe flowing out fast, you might have the same problem if you turn on the aircond really cold and for long duration.
Your aircond guy isn't doing their best at fixing your pipe. I seen mine insulated with rubber type material and some with spongy type of material over the piping.
Having any sealant or waterproof paints wont fix your problem. You gotta fix the piping issue. (Of coz make sure the problem isn't pipe leakage first)

This post has been edited by Untitled2: Dec 6 2013, 01:45 AM

Wah kao, very pro and informative. I believe not many contractor (or non) or aircond man will attempt such job o.O" One thing about Malaysia is that many contractors aren't professional, they came to the business by "common sense" which is why it lacks professionalism for a perfect job..

Plus, i think the cost if you were to hire a contractor to do such job should be quite high. Malaysian contractors always use these words "Okay one" , "No problem" and just Bantai only. lolz some do fix the problem but I do agree with affecting the house structure pillars.. But I think everyone does give in to the contractor.

If anyone find such great person to do this job, let me know, i might have things in the future that might need such expertise. haha.

Indeed, most handyman kind of job is all sub standard in Malaysia, which is why we are having a lot of roof leaking, pipe leaking, tank leaking, aircond water leaking. lol. (Electrical wiring also same =.=")

Even for car repair, really have doubts about their expertise.. but too bad Malaysia doesn't have any licenses required for car mechanics to protect road users. Nothing happen still okay. If anything were to happen on the road, it could be fatal..
Many car repairs probably does damage to a new car much more than everyone knows.. Especially when cars these days are very much electronics, normal self taught mechanics would not have a clue on whats happening..