"Jules77" wrote:

Figure my ignorance.. but I truly know nothing when it comes to home
repair.

Here's the situation.

I bought a new (older) home.
Its about 50 years old and prior to us moving in some work was done on
our behalf.

The room in question is a small powder room.
Wains Coating and hardwood floors have been installed.

A custom vanity was ordered and needs to be installed.

I was thinking it may not be hard to attempt this myself.. but..
figured I'd ask for advice.

Can the vanity be screwed into the wains coating?
Is that enough, or does one need to find the studs behind the wall?

This might be considerably more complex than it appears at first
glance. What is the relationship between the vanity (I presume it's
wood) the wainscoting and the flooring? Is the whole of the vanity
including the top within the wainscoting itself? Usually there's a
chair rail on top of the wainscoting; is it all below that? Is the
floor where you're going to put the vanity at exactly 90 degrees to
the wainscoting? And of course is the base of the vanity at exactly 90
degrees to the back?

What I'm driving at is that normally these measurements are not 90
degrees and normally the backs are not 100% even and normally the
wainscoting isn't flat either. There's a distinct art to shimming the
vanity (like installing kitchen cabinets) and scribing the back of the
vanity sides to follow the contours of the wall/wainscoting. If you
want a great-looking job and you haven't done it yourself before, you
might want to let someone with experience do the work.

OTOH if you're prepared to live with the gaps or cover them with
molding or they won't be seen go right ahead.

As to screwing it in, don't forget that all the weight is going to be
on the floor. You only need to stop the vanity moving around. If the
wainscoting is thin (5/16 or less) it's normally installed on furring
strips mounted horizontally on the studs. If the nailing strip at the
back of the vanity lines up with the furring strip (s) screwing
through the wainscoting into the strips should provide sufficient
support. OTOH if you have nice expensive wainscoting made from (say)
recycled 3/4 quarter-sawn oak, just screw into the wainscoting. Or if
you have cheap-jack plastic imitation wainscoting you might just
continue the theme and use construction adhesive g.