Palm tree roots lifting brick planter around pool

[Chad(Louisiana)]

About 6 years ago we built a swimming pool and we incorporated 3 large raised brick planters next to the pool.  We place 1 Sylvester palm in each one.  The planters are about 2.5 ft high and are about 6ft long by 5 ft wide.  last year we noticed  one of the planters started to raise up with roots coming out from where the brick meets the concrete.  We dig out around the edge and cut back all of the roots.  we then backfilled with soil and assumed it would correct the problem.  This year we noticed that the  other side of the planter is now raising up and the bricks are starting to crack.  My question's are, (1) Should we pull up the palms and plant something else? (2) Dig around the edges and cut the roots again but install a plastic root barrier between the Palm and the edge of the planter?  

[kinzyjr]

@Chad(Louisiana) Welcome to the forums.

I'd say give the plastic barrier a try if it isn't too much trouble and remove it if it doesn't work.  If it is an inordinate amount of effort to do that, I would move the palms and put something else there.