Hi i brought a Wickes newport Basin for my bathroom, i came to fit the new tap today which is a ideal standard mixer tap. the problem is when i tighten the nut to secure the tap, the tap leans back creating a gap at the front of the tap thus not sealing the tap to the basin.
on looking at the problem i have found the basin surface where the tap sits is uneven. its like it as a point in the center with two slopes. so when tightening the nut it pulls it on the back slope leaving a big gap.
any ideas how to solve