If the countertop is too large or too small contact the manufacture to adjust the fit.
Install marble countertop on the wall.
Apply a wet wipe using alcohol run across all marble surface area before using the adhesive.
Step 1 take proper measurements.
Kyle you should install some sideways 2x4 or metal cross bracing under the plywood that extends from wall to wall at or near the front and again half way back of the countertop.
If the fit is too large you can try to cut it to the correct size yourself with a circular saw but you risk splitting the marble.
Very rarely will you find walls perfectly square and straight.
Pay attention to any wavy walls or out of square walls because they will effect the installation.
Measure from the wall to the edge of the cabinets in multiple spots for both the width and length of the countertops.
Step 7 dry time allow the countertop to set overnight after examining the installation to make sure an even consistent bond has been created.
Marble bathroom countertops come in various textures and color tones.
Make sure to immediately clean up any excessive glue from the marble countertop.
It is best to have a professional adjust the fit.
Measure the area in which you want to install the counter top.
Record both the length and width.
You need a completely solid and stable base for the marble slab.