built in project with lateral files

[test123]

happy new year.

I'm designing a group of cabinets I will construct and install as a built-in credenza system in my home. This will sit below and will compliment the built in, wall mounted bookshelves I fabricated about 10 years ago (My wife is asking what my hurry is to finish the project
). 

The alcove for the credenza (and shelf system above) is 122' wide. The shelves are (4) 30" wide boxes, constructed of 3/4 red oak ply with oak board edging. Everything is finished with a wipe on clear varnish.

For the credenza, I'm envisioning (4) 30" wide frame-less boxes to continue the design of the shelves. The 4 boxes , from left to right, would be: bookshelf, 2 drawer lateral file, mixed drawers (1 lat file, 2 box drawers) and another bookshelf. The boxes would be fastened together and sit on and be anchored to a short platform to create toe kick space and. I'd fabricate a 1.5' thick top from oak ply top over 3/4 particle board, with hard wood edge.

My questions are mostly about the drawer cabinets which I have never tackled before.

1.  for the drawer cabinets, the only thing exposed to the room will be the drawer front which will be oak ply with hardwood edging. Looking for a suggestion on what to construct the cabinet carcass and drawer boxes from: stick with oak ply or can I use something cheaper--melamine or painted  (non oak ) plywood or MDF or MDO, etc. ?

2. do the lat file drawer boxes need to be 3/4" material? or can I safely get by with 1/2"?

3. the lat file drawers will house letter size file folders (11.5" wide x 9.5" high) and the orientation of the files in the drawer will be 11.5" dimension running back to front.  For the inside dimensions of the lat file drawer boxes, I'm allowing 2 extra inches back to front and an extra 1.5" from top of file folder to the bottom of the drawer above it. Does that seem like enough (or too much)?


4. the drawer boxes will be 15" deep, operating inside of a 16" deep carcass with 16" full extension slides. The top will have a 1" overhang. would you pay extra for a slide with an additional 1"of over-travel to make it easier to access the files?

5.   I'm thinking about installing a lock in just one of the 3 lat file drawers to secure tax returns, etc. has anyone else wished that they had more drawers lockable?

Appreciate your answers and any other general comments.

Thanks for looking.

[WoodworkerTom]

I would use 3/4" baltic birch for the file drawers and get good heavy duty hanging rails. We have office furniture from Ashley and they used 1/2" and crappy rails. They distort with the weight of the files when it full. Retrofitting better rails was a challenge with 1/2".

I am in the process of building new office furniture and am going the 3/4" route so the drawers and hanging files will last and last. For the time invested build it the best you can now to enjoy it for many years to come and perhaps pass its own to kids/ grandkids.

[dlbirks]

I built a drawer for hanging lateral files some time ago. The folders hang on aluminum bars(3/4 x 1/8) screwed to the inside of the drawer front and back. I sized the drawer so the hanging folders rest correctly on the aluminum bars. The drawer itself is behind raised panel doors.