In article ,
The Henchman wrote:
Tight budget, and I'm a novice diy'er.

My wife wants my to build a wall to wall bookcase that is floor to ceiling.
There will actually be 3 sections because we want the end sections to have
workstation or desks. They will be fastened to the wall. My wife and her
family suggested I make everything out of MDF which is cheep, easy to treat
and easy to by decorative faces and mouldings for.

However I'd like to seek opinions on how long 5/8" or 3/4" MDF will last if
two adults and two kids use this type of configuration for 20 or 25 years or
hopefully 40 years?. What's the life span of MDF for this type of
application? We are in Ontario Canada so air conditioning 3 months a year
and forced air heating for 7 months a year from a humidity standpoint. Is
there plywood that is affordable and nice to prime and paint and that we can
nail some mdf moulds to? Melamine is prolly out of the question cause of
looks and it's really tough to paint ( it's a home office library, not a
kitchen)

This room will be used a lot we think.


I made some wall-to-wall full height shelves and used birch plywood some
years ago but I finished them with watco, not paint. I used regular pine
1x12s for many of the shelves, the rest are also ply with some edge banding
that believe it or not I ripped from some old pallets. Pretty sure it's
maple. MDF is a good bit less expensive, but I'd be leary of using it
for shelves unless you keep them pretty short (like 24 or maybe 30")
or very lightly loaded, or incorporate upright supports into your design.
Longer MDF shelves will sag if fully loaded with books.

I do have a freestanding mdf bookshelf in an upstairs room with 42" shelves.
When they started to sag, I grabbed a few old oversize books nobody was
reading and crosscut them to height on the tablesaw, so that I could jam
them into the bookshelf near the center for an additional vertical support.

I wouldn't go so far as to say MDF can't be made to work, but take a look
at some 20 or 30 year old MDF furniture sometime, and very likely any
larger pieces will have some noticeable sag. I guess this would be a good
time for someone to make a joke about "the bigger they are the more they
sag with age...

--
Better to be stuck up in a tree than tied to one.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org