12:39 AM 05/20/2012
I live in Midwood, Brooklyn, and a number of years ago when we redid our house, we prepared the house for a future terrace in place of the current roof. Almost all this future terrace is going to be above the existing kitchen, so this is not a balcony that starts where the house structure ends.
When we opened the house (we have a brick house) during the construction process, we changed that whole section to have steel beams, added a drain system and the corrugated steel has been already installed there . Since we did not want to do the terrace at the time, the workers put on a pitched roof over the area.
Now, we are almost ready to finally rip that roof off, pour some concrete and install some guard rails to make our dream terrace. Our concern is this: How can we make sure that we are not going to start having water leaks, which in turn will go into the kitchen ceiling and cause problems. I realize that good water-proofing is needed (Karnak?) but then a friend of mine mentioned something about that we need to make sure to do "concrete flushing".
Since there are a lot of pro's on this forum, can someone please explain to me exactly what that is and is it really needed? All I know is that it is supposed to be done after the concrete has been poured on top of the corrugated steel.
Thanks, Mark (in Brooklyn)