Wooden Shelf - Horizontal Bracing

[Graniteman]

Hi,

I am looking for a solution to a shelving problem.

The walls are crumbly and I would like to be able to put up a shelf without putting in typical wall fixings.

I would like to support the shelf using a horizontal brace.

I thought there must be something already out there (e.g. extendable curtain pole but more robust) but I can't see it. Something akin to horizontal props but with finer control.

My rough thoughts (see picture) are two wooden supports braced with threaded rod, with a back plate at one end and the fine adjustment provided by an adjustable leg at the other end.

My main concern is ensuring the compression force remains i.e. for my solution the extendable leg doesn't unwind and the whole thing falls down.

Ultimately I am looking for the neatest solution that gives fine control over the extension of the bracing. I am a novice so open to all suggestions no matter how obvious.

I have also considered tie-rods, gas struts, springs but none seem to work in my head.

Many thanks

 

[bernardgreen]

The walls are crumbly

so they will crumble evne more when you put pressure on them

ensuring the compression force remains

if ( when ) the wall crumbles under the pressure then unless the horizontal "brace" can expand and still maintain the pressure then it will fall out. Hence a strong spring in compression pushing against the wall.

 

[Graniteman]

Bernard, pressure is force per unit area. By spreading an equal force over a greater are the pressure is reduced. Smart answers from smart people only please.

 

[bernardgreen]

By spreading an equal force over a greater are the pressure is reduced

Don't forget gravity, vectors, co-efficient of static friction, etc etc, ( co-efficient of dynamic ( or sliding ) friction might come into play later ).

Good look, be smart.....

 

[Graniteman]

If you can't contribute meaningfully to a well intentioned question then don't. Typical self important custodian of a forum. One thing you have mastered is the BS coefficient

 

[Burnerman]

There's nothing particularly wrong with your idea, so long as you are able to turn the right hand short length of threaded rod easily enough......maybe a couple of flats ground on the bar so you can get an adjustable spanner on?
Crumbly walls or not, after a while the walls won't compress any more and the support will be stable.
(It may even indent the wall to some degree, so the bar can't actually fall out).
I'd consider using 12mm threaded bar, which is readily available. What is the span- a metre or thereabouts?
John

 

[big-all]

if you re worried i would fix the frame to the wall then fix legs to the wall to transfer the load to the floor

 

[bernardgreen]

One thing you have mastered is the BS coefficient

BS = Be Safe ?

 

[Himaginn]

Self standing unit.

 

[Kealan]

You don't need a threaded rod connector if you're using rod; the easiest way I can see would be to drill clearance holes in each of your end plates, then put a large washer and a nut on either end of the rod, so the washers bear out against the end plates, and the end plates are free to slide along the rod. That way you can just turn the nuts away from one another and you'll increase the compression in the rod/walls without needing any joints