Plugging concrete blocks.

[Archibald Tarquin Blenkinsopp]

Hi, I have a little shelving project where I intend to use a large number of those London shelf brackets along with Contiboard or whatever is supplied these days.

My problem is uncertainty in drilling the holes, if I hit an indentation or small piece of quartz in the block, the resulting hole can end up a few mm out.

I have gone as far as making a guide for the SDS drill using a length of the shelf drilled with pilot holes where the shelf bracket screws should go, then nailing this to the wall before drilling through the holes.

This is time consuming and after a few uses the holes tend to widen out.

Methinks this must be a common problem, particularily for smaller fittings where there is little scope for "adjustment"

The other alternative is to find shelf brackets with numerous slots rather than holes, thus allowing "adjustment"?

Has anyone any ideas for a solution please?

Regards

AB

[tabbypurr]

Why are you doing that? For a long shelf, mount the 1st 1 or 2 brackets, mark for the rest & drill. For lots of small shelves, mark the wall up then drill it. No jig required.

Of course a jig can be quicker, but unless you're doing a warehouse full I doubt it matters. If you are, use steel for the jig, or better still just use it to mark the wall.

NT

[Jonathan]

I would start with a small drill bit to make a pilot hole an then drill the size you require.

Jonathan

[Archibald Tarquin Blenkinsopp]

Thanks, Yes I agree totally, but whether the blocks vary in quality or something, I'm not sure.

The suface of the blocks are full of little pits that "guide" the drill away from the intended route, so in this case a smaller pilot does not help.

Likewise there also seem to be extremely small pebbles or fragments of hard quartz/ rock thay again force the drill into the easiest path.

I am fully loading the shelves, consequently all the screwholes are being used in the brackets. I would say that the maximum margin for error in the screwholes is about 1mm.

This would be feasible on a plastered wall, but on bare blocks the run of shelving looks bad as the final hole can end up two or three mm away from the intended target. Needless to say for optimum loadbearing, I have to use the largest screws the brackets will take, allmost a push fit in fact, so there is little "give" when the screws start off at all angles to the wall.

AB

[John Rumm]

It sounds like the choice of bracket is not well suited to the wall. You could fix that by lining the wall with a sheet of ply first - fixing that where you can, then the LSBs will attach easily.

Else you will need a different type of bracket. Spur style shelving runners may be easier as there are more fixing holes and a bit of wiggle room (plus you can shift a whole strut left or right if you get a problem fixing position)

[Tricky Dicky]

Those types of bracket were never designed to be fitted to block/brick walls directly. The usual method is to fit vertical battens to the wall and woodscrew the brackets to the batten.

Richard

[Archibald Tarquin Blenkinsopp]

Thanks, I do actually have some spur shelving, it was pricey in comparison to the London brackets though, so I bought it for the conservatory. The left over stuff was going to go onto an end wall in the shed.

The ply you suggest is a good way forward, but I couldn't line the whole wall and even to follow the run of shelving would be pricey.

The thing that put me off the spur shelving was the lack of securing screws, they seem widely spaced and to be honest, I have overdone things when loading shelving. The mess when around forty cans of paint hit the deck was unbelievable. When I saw the disaster a few months later, the mix of oil paint, water paint and various solvents was a nightmare to clean up, in fact I had an additional layer of concrete added to the floor in the end.

I must admit I am tempted to test the end wall spur shelving to the fail point to see what kind of improvement is given. It might well be better than the London brackets by a long margin.

The paint wasn't the only thing to bite the dust incidentally, the last mishap occurred late last year on a similar shelf on another wall, two monitors and a submersible pump met their end that time.

Many thanks for the ideas. I will take a look to see what the options are with the plywood also, just in case someone has offcuts of half a metre by umpteen.

AB

[Brian Gaff]

I tried this once and encountered a block of something more substantial than breeze block right on the edge and of course the hole then went between the blocks and hence in the wrong place.

Brian

[Archibald Tarquin Blenkinsopp]

:-) Just when I thought I knew it all!

Many thanks. It should have been patently obvious really. I never guessed.

An hour or two with the table saw and the addition of some serious screws would have improved my quality of life no end!!

Even at the latter end of my lifespan I'm still learning that my level of ignorance is totally unbounded.

This will definitely be the next step, I will start replacing the existing shelf brackets with battens and the same type of bracket. The big advantage being that I dont even have to empty the shelves that are fitted already.

Thanks, I'm very grateful, this is a bit of a DIY fix that will not for once involve starting virtually from scratch.

AB

[Dave Plowman (News)]

Assuming looks aren't the most important bit, a Spur type is ideal in that they the support rails can be as long as you wish with a greater chance of finding decent fixings, and you can have as many per length of shelving as you want for the load.

If you must use a type of bracket for looks, I'd be inclined to sink some wood into the wall and find the best fixings to the wall for that. The brackets can then go anywhere on it.

[Archibald Tarquin Blenkinsopp]

Yes, I think that's the way forward.

The current brackets are not the strongest anyway and I have put additional brackets in where the loading is high.

Direct into blocks is virtually impossible without emptying and removing the existing portion of shelf. Battens will allow a magin of error for fixing into the blocks, yet allow me to add additional brackets into the batten with the aid of a length of 2x2 to "lift" the shelf slightly when screwing the extra bracket to the wood.

By spur, I understood this to mean the vertical rails where the height is adjustable dependent on what slots were used.

Are you suggesting there may be a horizontal run of slotted metal to take as many or few brakets as needed?

Regards

AB

[John Rumm]

As suggested in another post, then a 2x1 batten fexed to the wall will do the job. If you make it a long one, you can fix several LSBs to the same batten for multiple shelves.

They actually work better than the LSBs IMHO. The main advantage of them is the length of them means the shelf load has much less mechanical advantage pulling on the top fixings.

(most of the load is carried in shear on the screws anyway)

Hmmm, colourful ;-)

IIRC, the silverline version of it is cheap enough, and not far of the stength of the original (although slightly incompatible since the uprights are not quite as deep, that can make getting real spur shelf supports into the "imitation" uprights a bit more difficult.

Any timber will do to be fair so long as it extends up and down enough to spread the load and resist the turning moment of the shelf supports.

I have a wood storage rack high up on the wall in my workshop. The uprights are made from 2x2, but well fixed to the wall with 5.25" screws (the length required to get through the ply lining, 2" of insulation, and still have enough meat in the brickwork). They carry a couple of rows of outriggers (also 2x2" but with ply gussets). It seems to hold up several hundred kg of oak, maple, and assorted other board awaiting use.

[Dave Plowman (News)]

Correct.

No - you just use more vertical and brackets.

[tabbypurr]

If you load shelves heavily then Londons are the last thing you should be using. But as it's a shed there is an easy workaround: add a vertical leg or 3 running up the front of the shelving from the floor.

NT

[newshound]

+1 for the general strategy, also I certainly would not be using contiboard for the shelves (unless supported by a full length batten, or perhaps an aluminium angle).

[Dave Plowman (News)]

Depends on the loading and spacing of the brackets.

The plastic covered sort of shelving is very convenient for many things.