Dear all,
i am currently doing maintenance work on a 2-storey building with massive moisture on the ceiling in one of the rooms (floor decking sheet under the slab). This floor decking sheet is cladded in gypsum board ceiling which was subsequently damaged due to the excessive moisture coming from the aluminum floor decking sheet. Both rooms are fully airconditioned with the above room utilizing airconditioning unit more often.
At first, i thought of humidity as the culprit since hot air would bring more moisture than colder air but after leaving both rooms without A/C for a day, the moisture accumulated more (the moisture all over the ceiling looks like the moisture we see if defrost a refrigerator unit. The moisture dripped into the floor like a water leakage. According to another opinion while doing research, buildings constructed barely a year has this excessive mositure on the concrete slabs and that this might be one of the reasons. I have also checked all possible source of leakage like, spinkler system, water lines, possible rain run-off seepage into the wall and seep into the floor but to no avail.
My problem is how to eliminate this moisture and resolve it once and for all. Does the floor decking sheet, prevents concrete slab from drying faster or is there was a previous accumulation of water into the concrete floor slab which is currently trapped by the aluminum floor decking sheet ? I would really appreciate any professional advise on this.matter. thank you so much.
In dire need of a solution,
Albert G.
AlbertG,
Kung yun metal deck ng underslab ang nag aacumulate ng moisture . You need to check the temperature of the metal deck (under slab) and the temperature and relative humidity of air inside the room? Pwede kse malamig yun metal deck then mataas yun Relative humidity ng air kaya nag moist yun metal deck.
Some literature...
http://www.engineeringtoolbox.com/dry-wet-bulb-dew-point-air-d_682.html
You need to get the data para malaman mo kung alin yun problema.
or mag try ka ng insulating paint. Paint it sa portion ng metal deck then observe. Mapapansin mo naman kung magpapawis yun bare metal deck vs. metal deck with insulating paint. If this will solve the just paint the metal deck with insulation paint.
bryant77.,
Thank you so much for the advise. i will take both and see if that would resolve the issue. I think the latter solution is the most practical. Maaaring malamig na nga yung metal deck dahil almost 24/7 naka-on A/C ng top room compared sa ilalim na room. Maaring mataas humidity ng air na pumapasok sa ground floor room which causes accumulation of moists sa metal slab. But given thatm mauulit ng mauulit ang issue, as per report, there was this prolonged roof water leak issue prior sa issue na to and i just thought na baka nag accumulate na yung water through seepage under the slab, Nonetheless, thanks for taking time to help me out with this one. I really appreciate it,
, i'm not an engineer nor a contractor, but your right, without identifying the cause of the problem (exessive moisture), chances are, it will happen again. my personal thought's on this, assuming that, as you mentioned, all possible sources of water leakage has been ruled out. since the floor slab uses steel decks ... i think the problem could be due to the thickness of the concrete that was poured in the floor slab during construction ... most likely, the builder (with or without the knowledge of the owner) reduce the thickness of the concrete slab to save on cost knowing that the steel deck can handle the structural changes ... you can easily check this by drilling a hole (e.g highest point of the steel deck) from the lower floor to the upper floor and then measure the thickness and then compare it with the bldg plan.
a thin concrete slab between floors with a steel deck at the bottom, can easily result in moisture buildup due to a big difference in tempreture between the upper and lower floor. this will always be seen at the steel deck area - ika nga, nag papawis yun steel deck. my archi and engr friends said that after 3 months, a slab should be fully cured and highly unlikely that any water can be trap in the slab for a long period of time. so it's logical that the water leakage is a result of what is happening in the environment in the 2 floors.
painting the steel deck with insulating paint may stop the water leakage in the short run but it will create other problems if the original problem has not been resolve - the moisture can still occur and will accumulate between the insulating paint and the steel deck, causing the steel deck to rust and corrode over time - steel decks are mostly GI sheets with a coating to prevent rust. once the steel deck is corroded, the paint will peel off and you have the same problem again ... cheers
Boo!
What is your room temperature? ceiling void temperature?
This is ventilation problem.
