shelving: spacing of rails?

[The Natural Philosopher]

19mm chip mealamine or not as cost allows. Or 19mm block. 15mm is acceptable: 12mm is not.

[The Natural Philosopher]

Correct.

brackets will stand standing on (just) though not without bending. Single screw in masonry will take all your weight.

:-)

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Fred saying something like:

My most recent heavy-duty shelving was made of ripped lengthways 19mm shuttering ply. Looks absolutely fine in a workshop.

[Fred]

Really, why is that? I haven't had a play with all the variables in the sagulator; does chip flex the least or is there another advantage I haven't thought of?

The sagulator gives a deflection of so many inches per foot but what figure should I be aiming for?

Is this tool just for shelves or is this the application I have heard people talking about on here for joists and floorboards etc?

Thanks.

[Fred]

Sorry to be so thick. By block do you mean blockboard?

Thanks.

[Fred]

Crickey. I hadn't realised a little screw could be so strong. So only one is needed to hold the weight and the rest are just over engineering? Thanks.

[John Rumm]

12mm contiboard for example...

Yup ply is quite good, although a bit more expensive. Shuttering ply can be quite cheap, but the finish is not as nice and its not quite as strong as the better grades.

[John Rumm]

Chip does not flex too much, and is cheap. In fact, flooring grade chip would probably make nice cheap workshop shelves since its usually sold in 8x2' sizes, and is 19mm or 22mm thick. Usually under £7/sheet.

Depends on what is aesthetically acceptable, and also how much load you are planning on storing.

I am not even convinced it gives accurate answers for shelves - it certainly gives radically different answers to Superbeam on joist sized timbers.

[John Rumm]

It depends on how you load the screw. Its strongest in shear - i.e. a lateral force applied tight against the wall. Its fairly strong but not as good in bending, and its weakest in traction (i.e. the screw itself is very string, but it can be pulled out of the wall - where the type of masonry and plug fit etc will play a big part in how easily).

So a shelving upright with a bracket protruding will place most of the load on the screws in shear, and some on the screws above the bracket point in traction, and also the upright under a bending moment - with the lower section being restrained by the wall. The longer the upright, the more leverage it has to control the forces - longer uprights will take bigger loads the short ones.

[Andy Champ]

Chip tends to sag if left under load for along time. Arrange it so you can turn the shelves over!

Andy

[The Natural Philosopher]

I did. Sorry.

[The Natural Philosopher]

Well that's as long as it is firmly into a good wall.

Never climbed using pitons? One 1/4" shaft hammered onto a crevice.

people trust their lives to them.

[The Natural Philosopher]

Not totally accurate, but near enough. The SCREW is strongest in tension actually. But the connection to the wall is not.;-)

[John Rumm]

Ain't that what I said?: "the screw itself is very string, but it can be pulled out of the wall" (if one ignores the typo ;-)

The point of relevance is not really the actual strength of the screw itself, but its performance in the application that counts.

[chris French]

I know it depends on the material, but for a decent thickness shelf I reckon about a 60cm or so spacing for shelves that are expected to take a reasonable, but not extremely heavy load is what I go for.

I've just checked the shelves in the pantry. I put up a 19mm MDF shelf (probably about 18 inches deep) supported on London brackets at about

68cm centres. It has a pretty heavy load stacks of tins, jars, bulk bags or rice etc. No sagging so far. This is probably about what you shelves above are at by the sound of it.

The shelves on our Ikea Billy bookcases are about 76cm long and seem to be holding up well.

[Fred]

Blockboard sounds like it might be a good, strong choice. Would it be better than the alternatives?

When I was young and naive, I used to buy the contiboard "strips" but I think these now cost about £8 for 8' x 9" so it is probably an expensive way of doing things.

I think it would be cheaper to buy one big board and rip it into shelves. Or since the boards are so bulky to move, get the timber merchant to cut them for me.

If I ripped a melamine faced sheet that would leave bare edges but if I really wanted a pretty edge, I suppose I could buy the iron-on edging strips. Appearance might not matter in the garage but would if the shelves were elsewhere.

The melamine face does make the shelf prettier but IIRC there is still a warning on the label that it doesn't like water.

Thanks.

[John Rumm]

You can also get so called "furniture board" - i.e. veneered chip. If you varnish that with something waterproof it can look good and resist water.

[Fred]

Sorry that is what I was talking about; I thought melamine faced chipboard was contiboard/furniture board. have I got that wrong? Are they two different things? I quite like the idea of using blockboard, perhaps just for novelty value - I haven't used it for anything else, but it is twice the price of naked chipboard.

[John Rumm]

Contiboard (i.e. the brand) make both. The melamine faced stuff is usually smooth and either single colour, or a wood effect slightly textured finish.

The furniture board is coated with a real wood veneer rather than a melamine type coating, and it will take varnish and stain like real wood. The only thing you can't do it route the edges!

Not see blockboard about for ages! (if by that you mean a couple of laminations of ply with wood strips/block sandwiched between).

[The Natural Philosopher]

Rout, John, rout.

Routres "Route", Routers "Rout"..;-)