cutting in a masonry box. epoxy or hydraulic cement

[kwired]

Keep in mind though that mortar will not seal out water!
Are we talking about the interior or exterior of a wall?


Tapatalk!

Neither will the block you are cutting the box into. Paint or other sealers can be applied to the surface though, making for a reasonably dry interior for a vertical surface that is not submerged in water. It would still not be a very good choice for a wall of a swimming pool.