On 12/12/2015 1:44 PM, Dave wrote:
When ceiling a French drain for the basement or floating slab which would
be better? Great stuff or backer rod? I have read pros and cons on both so I'm
looking for someone who has
experience that can help me make a decision before we install a mitigation
system in our house. As always any help and good advice is always
appreciated thank you and advance

Huh? What aspect of the drain are you trying to seal?
Presumably, anything you're talking about, here, would
be below grade and have to endure those conditions
"indefinitely"...