The gap in question was previously filled with either fiberboard or concrete crack sealant but enough of it has deteriorated to conceivably allow moisture in.
Seal gap between concrete floor and wall.
Fill the crack with urethane caulk similar to what you would use for driveway caulk.
Even so the new concrete does not bond with the already cured footings so a tiny gap exists between the two.
Remove the baseboard if present to expose the gap between the subfloor and the wall face.
The water being blocked by the sealant will find another gap in your foundation to enter the home.
This will hopefully be the fix that keeps that wall of the sunroom nice and dry.
Typically this will be cracks in your foundation.
Snip the opening of the tube at a 30 degree angle making the opening the same size as your gap.
However it s not that simple.
However it will eventually fail in one of two ways.
It works perfectly as a concrete expansion joint sealant.
In the short term a sealant applied along this gap between your basement floor and wall may prevent leakage.
Under ordinary circumstances this gap is too small to admit water.
To remedy this issue i installed backer rod in the gap that i then covered with concrete crack sealant.