Got flooded last year with Irene....we just finished renovation around August of this year !
The sewar system could not catch up - so it just all started coming out from the lowest part of the house.
Got a checkvalve installed. In hindsight, I should have also have had a ballvalve installed Right Behind it.
Fast forward to upcoming Sandy.
The premise of the checkvalve is that as water leaves my premise, it pushes the flap open....and let's whatever go past the door.
To be thoroughly protected, am I NOT SUPPOSED to use any *water-sewar* in order to prevent any water from coming in, should there be backflow of water in the sewer pipe.
OR, let's just say the kids flush the toilet and there is backflow of water pressure against the door trap.
Will the door just not open due to the greater pressure against it - In Essence, keeping me protected *aside from the buildup* behind the door.
Or is it plausiable that if it's not that much pressure, there may be a chance the door will open, and then *remain open* due to water pressure.
I have not thought out all the options as I'm busy buttoning up the house.