built-in bookshelves - on top of flooring or not?

[Joe User]

It may be a dumb question, but I don't know the answer so I'll ask it
anyway.

I'm planning on building floor-to-ceiling bookshelves completely
covering one wall (at least). The room is currently carpeted, subject
to change to hardwood in the future.

Do I build these shelves directly on the carpet, or do I go to the
subfloor and trim the carpet to match?

If it were a hardwood floor, same question: on top of the hardwood or not?

thanks,
-j

[Edwin Pawlowski]

I'm planning on building floor-to-ceiling bookshelves completely covering
one wall (at least). The room is currently carpeted, subject to change to
hardwood in the future.
Do I build these shelves directly on the carpet, or do I go to the
subfloor and trim the carpet to match?
If it were a hardwood floor, same question: on top of the hardwood or not?

I'd build it on top of hardwood, but I'd cut and remove the carpet.
Hardwood floor is part of the structure and will help support the shelves.
Carpet is decoration and will be changed at some point. It is also not as
good a support because of the compression.

[woodworker88]

If the bookshelves are going to be permanetly attached to the wall,I
would go ahead and rip up the carpet and build directly on the
subfloor. Otherwise the pile of the carpet will crush with the weight
and the bookshelves will be left hanging from the wall, which is
probably not what you intended.

[w***@yahoo.com]

Take the carpet back and then trim the carpet to the bookshelf. If
hardwood, run hardwood up to the bookshelf. Then, for a nice built in
look, you can run the baseboard around the front of the unit and
everything will be at the same height.

[Knothead]

Chances are that there are carpet tack strips that would interfere with
leveling the unit anyway, cut it back.

Knothead

[SonomaProducts.com]

Take up carpet. If Harbwood is already in, build on top of it. If not,
build on sub floor.

[RVH]

I agree with removing the carpet. You should also set the case(s) on a
box or stand. Likely the floor is not completely level. A box
underneath will all you to get "straight" with the wall and shim up the
box to assure a level base for your cases.

RVH

[TEF]

If you a certain that you will later install hardwood flooring (an you know
if it will be, say, 3/4" thick), you might want to remove carpet and
substitute plywood (or whatever) in the same thickness of the intended
hardwood flooring. Moreover, if you let the front edge of the bookshelves
overhang (by an inch or so) your plywood platform, it will make for a neater
and easier installation of you hardwood flooring. Rather that having to
make intricate cuts, so that you hardwood butts up to the bookshelves, the
hardwood flooring can be slipped under the fronts of the shelves. In the
short term, the carpet can fill this gap at the front and when hardwood is
put in, it will go much faster. I've done this with kitchen cabinets, in
order to spend less on flooring and speed up the installation of flooring.

Post by RVH
I agree with removing the carpet. You should also set the case(s) on a
box or stand. Likely the floor is not completely level. A box
underneath will all you to get "straight" with the wall and shim up the
box to assure a level base for your cases.
RVH

[Mike]

Post by TEF
put in, it will go much faster. I've done this with kitchen cabinets, in
order to spend less on flooring and speed up the installation of flooring.

Plus, unless you jack the cabinets up, the dishwasher will not go
under the counter tops.

Mike O.

[Mike]

Post by Joe User
I'm planning on building floor-to-ceiling bookshelves completely
covering one wall (at least). The room is currently carpeted, subject
to change to hardwood in the future.

I agree with the majority here who suggest taking the carpet up and
cutting it back to the bookcase one they are installed.
If you go to a wood floor later you can always cover any space left
(between the new floor and the bookcase) with a base board or if you
have a toe space you could use base shoe.
BTW, if you are going to build these on the floor and stand them up,
be sure they are short enough to turn up in the room.

Mike O.

[Joe User]

Post by Mike
BTW, if you are going to build these on the floor and stand them up,
be sure they are short enough to turn up in the room.

LOL. I've already thought of that one. I've probably spent more time
thinking about ways to do it wrong than I have actually planning the
design. I'll probably go with short base on the floor (6" to 10"
maybe), then shelves then a single top trim piece that fits flush
against the ceiling.

I want to build (and finish) it in the shop and then install. I suspect
there'll be several trips from the shop to the house for "dry fits".

thanks for all the advice.

-j

[alexy]

Post by Joe User

Post by Mike
BTW, if you are going to build these on the floor and stand them up,
be sure they are short enough to turn up in the room.

LOL. I've already thought of that one. I've probably spent more time
thinking about ways to do it wrong than I have actually planning the
design.

Let me add another for you to think about: DON'T assume that your
walls are straight. Make any piece that butts up against a wall
oversize so that it extends beyond the body of the shelves. And rabbit
the back of that piece so that you have wood only about 1/4" to 3/8"
thick as a "flange" extending beyond your shelves. Then when you
install your bookcase, move it as close as you can to the walls, and
use a compass to scribe a line parallel to your wall on this flange.
It will be easy to cut the flange leaving only the need for a small
bead of caulk (assuming you are painting, or small piece of trim if
that is your preference) to make it really "built-in".

Don't know where I saw that advice, but it saved me on my first
bookcase--the plaster walls in my circa 1945 house at the time bowed
almost a full 1" between floor and 8' ceiling!

[Lee Michaels]

Post by alexy
Don't know where I saw that advice, but it saved me on my first
bookcase--the plaster walls in my circa 1945 house at the time bowed
almost a full 1" between floor and 8' ceiling!

Gotcha beat.

I had to install some bookshelves in an office once that had an outward bow
of four inches over about ten feet. Luckily, I was able to measure ahead of
time. I ended up building a cabinet to cover the high point. With enough
custom cutting covering and moulding, we covered it all up.

[Joe User]

Post by alexy
Let me add another for you to think about: DON'T assume that your
walls are straight.

A buddy bought an old house and was redoing one of the walls (forget
exactly what he was doing; plaster to sheetrock, maybe?). The ceiling
was several inches lower on one end of the wall than where he started.

My house is in pretty good shape, as far as bowing and so forth.
Existing freestanding units seem to indicate fairly flat walls (but I'll
check 'em anyway).

-j

[Mike]

Post by Joe User
design. I'll probably go with short base on the floor (6" to 10"
maybe), then shelves then a single top trim piece that fits flush
against the ceiling.

Sometimes we build them with a toe space of about 4" and install and
level the toe first. You can do the same thing with your base unit.
Then you can build the cabinets about 1/2" short of the smallest
measurement between the leveled base and the ceiling.
It takes two guys to lift and slide the cabinets between the toe and
ceiling without marking up the ceiling. Then you can use cove or
small crown at the top.
If you use a large enough crown at the top, you can build the entire
unit and turn it up.
Side to side can be another problem. If the walls are fairly good
(plumb and straight) you can build the unit(s) slightly undersized and
use a molding on the sides too.

Mike O.