You can of course provide additional support by having a batten at the back of the shelf - this would help prevent sagging over a long area by making the shelf effectively thicker.
I've seen several sets of sagging contiboard shelves. Proper wood (ok, even cheap softwood) seems to work well - 22mm x 200mm is pretty sturdy stuff. Actual calculations are probably a job for that beam program mentioned in the joist thread :-)
> However, this time they're to go along a single large wall (as opposed
I have a mainly hardbacks on chipboard shelves supported at 450-500mm intervals over 3.5m. It's sagging very slightly. Spending a bit more on real wood might save on supports. One thing I noticed on some professionally-made shelving is a groove routed underneath to take steel U-channel.
I'm slightly worried by those Screwfix strips, though -- they look a bit flimsy. I used the sort (from Homebase) that have vertical slots for the brackets made of about 2-3mm thick steel. Yes, the whole thing was expensive.
================================== I think you're looking at the wrong support system. The bracket you cited is for fixing inside a bookcase and you would need four such strips (plus fittings) for each lot of shelves.
This kind of thing would be more suitable, assuming that you want to fix shelves directly to the wall:
formatting link
are several similar systems so a browse through Screwfix or your local Wickes should give you some ideas.
=================================== This type of support strip is usually rebated into the side uprights of a bookcase with two each side. Small brackets (Called 'Tonks fittings' - each about 3/4" square) are hooked into the slots giving support at each corner of each shelf. They used to be a standard fitting in library bookshelves because of their flexibility in use and may still be so used.
from B & Q there is very nice French pine flooring; 20mm thick,
145 wide, and 2m long. A pack of 4 is =A320. Expensive, but it is good wood and has a very good varnish finish on one side and it looks nice. The 'book' side of the shelf should be given a quick rub down and varnished with a couple of coats of quick setting poly to reduce the boards bowing due to moisture ingress on one side only.
I've got my supports at nominal 700mm centres. Haven't done any sums but with solid wood that thick that seemed reasonable on the 'looks right' basis.
================================== I've got two or three of the uprights from B&Q in use as straight edges which is a good way of getting a few reasonably priced straight edges.
until I've put the shelves up I don't know the weight of books, nor do I know what variety of cheap, fast-growing softwood I'll be getting. I suppose I can retrocheck my figures and gnash my teeth when I realise that I've overspent by about a zillion pounds over-engineering as usual.
> However, this time they're to go along a single large wall (as opposed
There is interaction between bracket spacing, shelf thickness, loading weight and shelf material. So theres no one answer. 2' spacing with 3/4" real wood and heavy loading (much more than a row of paperbacks causes no sag.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.