Bookcase Plinth

Greg Esres wrote:
>
> So if you were building multiple units, you would have a plinth whose
> structure mirrored the sides of the various units. In other words, if
> you had 3 book case units, you would have one plinth that supported
> all three,

Yeah.

and you would have some cross members to lie under each of
> the cases sides?

No. The long stringers carry the sides, as well as the shelf. There
are a few crossmembers to prevent bowing.

>
> I'd kinda be worried that any width deviation of the book cases would
> end up with the last case hanging off the edge. :-(
>

Not if you're reasonably careful.

Greg Esres wrote:
> I'm looking at a bookcase design that has a platform constructed out
> of 2x4's, which is shimmed, and then the bookcase rests on top. The
> trim hides the plinth.
>
> I'm not convinced of the utility of shimming the hidden plinth as
> opposed to just shimming the bookcase itself, then attaching the trim.
> If the platform is smaller than the perimeter of the bookcase, then
> the entire weight is supported by the bottom shelf, which isn't good.
> It really must be exactly the same dimensions as the bottom of the
> bookshelf and thus seems to add extra work without benefit.
>
> Am I missing a potential benefit?
>
> Thanks

It's easier to level the platform first. Typically only the front of
the plinth is recessed. If the sides are supported by the bottom it'll
be OK.
Phil Brown

Phil Brown wrote:

<<If the sides are supported by the bottom it'll
be OK. >>

Couple hundred pounds of books supported by one shelf?

Barry wrote:
<<My ends line up with the outside uprights, the bottom shelf doesn't
support the whole unit. >>


So if you were building multiple units, you would have a plinth whose
structure mirrored the sides of the various units. In other words, if
you had 3 book case units, you would have one plinth that supported
all three, and you would have some cross members to lie under each of
the cases sides?

I'd kinda be worried that any width deviation of the book cases would
end up with the last case hanging off the edge. :-(

Thanks

DanG wrote:
<<I like to cut the bottom of the sides at a slight angle so that the
bookcase has to lean back against the wall, this causes the plinth
box to have a different front and back .
>>

Why not just shim it that way?

Greg Esres wrote:
> I'm looking at a bookcase design that has a platform constructed out
> of 2x4's, which is shimmed, and then the bookcase rests on top. The
> trim hides the plinth.
>
> I'm not convinced of the utility of shimming the hidden plinth as
> opposed to just shimming the bookcase itself, then attaching the trim.
> If the platform is smaller than the perimeter of the bookcase, then
> the entire weight is supported by the bottom shelf, which isn't good.
> It really must be exactly the same dimensions as the bottom of the
> bookshelf and thus seems to add extra work without benefit.
>
> Am I missing a potential benefit?


I like to do this when I'm building multiple unit built-ins and window
seats. I can create a level base to install the boxes on, ala
cabinet-style. My bases are strips of cabinet grade ply instead of
2x's, as I find the plywood more stable. I've never had to buy extra
plywood to build the base, I always seem to have suitable leftovers,
especially since the face veneer species doesn't really matter.

My ends line up with the outside uprights, the bottom shelf doesn't
support the whole unit.

The load of a bookcase rests on the 2(?) sides. I like to tie the
two sides together with an apron under the bottom shelf. An easy
way to stabilize this plinth is to create a four sided box. I
like to cut the bottom of the sides at a slight angle so that the
bookcase has to lean back against the wall, this causes the plinth
box to have a different front and back . I still like to pin the
top of the bookcase to the wall by some method, but a slight lean
helps to compensate for carpet tack strip and load dynamics.
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
[email protected]



"Greg Esres" <[email protected]> wrote in message
news:[email protected]...
> I'm looking at a bookcase design that has a platform constructed
> out
> of 2x4's, which is shimmed, and then the bookcase rests on top.
> The
> trim hides the plinth.
>
> I'm not convinced of the utility of shimming the hidden plinth
> as
> opposed to just shimming the bookcase itself, then attaching the
> trim.
> If the platform is smaller than the perimeter of the bookcase,
> then
> the entire weight is supported by the bottom shelf, which isn't
> good.
> It really must be exactly the same dimensions as the bottom of
> the
> bookshelf and thus seems to add extra work without benefit.
>
> Am I missing a potential benefit?
>
> Thanks
>