Most practical way to add unit on top of a desk?

[Mjward]

Good morning!

Diagram below, essentially putting shelving units on each side of a built-in desk. My intention is to line up the sides of the units with the sides of the desk i.e. not possible to screw up from underneath.

I'm thinking loose dowels & wood glue might work to stop the bottoms from moving (the tops will be mechanically secured to the wall).

Is there a better/more secure way to do this?

The shelving units will be made out of ply that I am not painting ie keen to avoid pocket holes/visible screws etc

TIA!

 

[niall Y]

Given the restrictions, fixing with dowels should be okay. After all, they are just for locating the units as they are being fastened to the wall. It also causes the least damage to the desk top.
You could , of course, just fix a bottom on the units and have them resting on the desk, but still fixed to the wall. That way, if anyone moves the desk inadvertently, there will be no damage done.

 

[Mjward]

Given the restrictions, fixing with dowels should be okay. After all, they are just for locating the units as they are being fastened to the wall. It also causes the least damage to the desk top.
You could , of course, just fix a bottom on the units and have them resting on the desk, but still fixed to the wall. That way, if anyone moves the desk inadvertently, there will be no damage done.

You've given me an idea. Could possibly make the lowest shelf a "base" a couple inches off the bottom, use L brackets underneath to attach to the desk, and cover the whole thing with the same 45mm face frame I'm using for the verticals.

 

[recipio]

If the shelves are fixed to the wall do you need them fixed to the desk as well ? I would simply leave them in position - the worst that will happen is that the desk will move little. Otherwise if you have a biscuit joiner the Clamex S20 fittings would allow a secure K/D fitting.

 

[Mjward]

If the shelves are fixed to the wall do you need them fixed to the desk as well ? I would simply leave them in position - the worst that will happen is that the desk will move little. Otherwise if you have a biscuit joiner the Clamex S20 fittings would allow a secure K/D fitting.

Possibly not, first time doing this. I was thinking to fix bottom and top mostly due to their height, the shelf/bookcase carcass will be 1.6m so was thinking at that size to do both. Essentially each vertical will be 36mm (2x18mm) ie very solid and when glued down are super unlikely to move but just thinking practical belts/braces where it makes sense to etc.

No biscuit jointer, have a domino and was originally thinking wide domino for alignment but a wide domino gives you wiggle room in one direction only, whereas was thinking with a wide dowel (i.e. just a larger female hole in the desk) it gives greater room for precision adjustment.

 

[Terry - Somerset]

You could fasten the bottom shelf to the wall in the manner of a floating shelf.

The only sign of fixing would be a on the underside of the shelf to clamp the "dowel" that projects from the wall - a grub screw would be best as this would sit flush or below the surface of the shelf.

 

[Cabinetman]

To avoid marking the desk top you could have a solid base as mentioned and have the outer two uprights extend downwards slightly, then if you were to tie the two units together, possibly with a "splash back"you wouldn’t need to fasten them to the wall either, the splashback would also stop things dropping off the back of the desk.
Ian
Edit You could also extend the backs downwards slightly allowing you to fasten to the back of the desk.

 

[HOJ]

My method when doubling up ply/mdf to make thicker panels, for not only fixing to the wall but to a top, has been to router/spindle a rebate
down the back edge of each board and a stopped rebate along the bottom before gluing them together, giving me a channel, I machine up separate strips of timber to fix to wall/top and simply slide the unit on to them, with either some glue or screws in and unobtrusive place through the sides to hold it in place.

Drawing may explain better:

 

[Mjward]

My method when doubling up ply/mdf to make thicker panels, for not only fixing to the wall but to a top, has been to router/spindle a rebate
down the back edge of each board and a stopped rebate along the bottom before gluing them together, giving me a channel, I machine up separate strips of timber to fix to wall/top and simply slide the unit on to them, with either some glue or screws in and unobtrusive place through the sides to hold it in place.

Drawing may explain better:

View attachment 182529

Ooh I like that

 

[Mjward]

Thank you all, some cracking tips to digest. Think I'll do some test/mockups and see what I find works best

 

[recipio]

My instincts are not to permanently join the shelves to the desk - you may want to move the piece at some stage ?
If you insert a shelf at the bottom to sit on the desk you could then hold the units in position with two threaded inserts and some nice bronze finished bolts. No need for a wall fixing then.

 

[Mjward]

My instincts are not to permanently join the shelves to the desk - you may want to move the piece at some stage ?
If you insert a shelf at the bottom to sit on the desk you could then hold the units in position with two threaded inserts and some nice bronze finished bolts. No need for a wall fixing then.

It's forming part of a larger built-in library i.e. I'm abolishing freedom of movement