Hey guys i installed my first acrylic tub last week. the tub is installed, I ran my backer board 1/4" above the 1" flange on the tub.(as per mirolin instructions ) I also coated the backer board with mapie auqa defence. my problem now is what is the best way to seal the 1/4" gap I have between the backer board and the tub flange? I will be installing 6x6 tile for the tub surround. Looking at it now, i maybe should of ran the backer board rate over the tub flange, but like i said I am a newbie reading the tub instuction sheet. thanks for the help