Expert: Bruce E. Johnson - 1/31/2009

Question
building an office under a patio with a 6" slab of concrete. there is a steel beam running across the ceiling of my new office. i am putting a dropped ceiling in however the beam wants to sweat. will the heat from this room put a stop to this sweating or do i need to do other things to stop this

Answer
Hi lee, if the beam is sweating from lack of air circulation and you are going to aircondition this space then it is possible that the beam will quit sweating.  However, if the beam is wet because of the slab above seeping moisture then this area will be perpetually wet.  If the patio above is sealed and drained properly then the answer to your question is yes, provided you allow for conditioned air to enter and exit the space above the dropped ceiling. This can be done by installing a couple of transfer grills in the ceiling grid to allow heat and cooling from the room below to treat the air in the space above the dropped ceiling.  I would run a dehumidifier in this room for several days to see if I can dry this space out before covering it up with ceiling grid and tile. A simple humidity gauge will tell you how humid this room is.  Ideal interior humidity is 45-50 percent, anything above that and you need to remove it or moisture will begin to accumulate.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com