How Close To Edge?

[toolsntat]

My fix when things get crumbly/dodgy is to use dowling, drill hole to suit, cut dowels to length, score the dowels with teeth on hand saw, pump in enough 5min PU glue, dip dowel in water and insert. 10 min later, cut off flush.
This is especially effective when fitting curtain pole mounts ( 3 holes in 1,1/2" diameter)
Cheers Andy

 

[custard]

Thank you all, some very good points. The key take out is that I was wrong to try and get as close to the edges as possible, and coming in a bit more really isn't a problem.

Thanks,

 

[Alpha-Dave]

I keep reading the title and hearing this in my head.

 

[MusicMan]

I'm not absolutely convinced that sag is the major issue here!!!

No you are right, crumbling of the edge would be. But if it is far enough away from the edge to not risk crumbling, might as well get it right for sag! And Custard di want quantitative data!

 

[clogs]

all this for just one screw close to the edge.....hahaha..
glad it's not a bridge.....
a brill forum...

 

[Oddbod70]

Late to the party, sorry.

But I'd be very tempted to drill and either use resin to fix a stud or drill and stick in a concrete screw or bolt. It would depend what was nearest to hand. Either will hold the shelf whatever you could realistically want to put on it. You can go quite close to the edge with either, but I use the rule of thumb (25mm in my case!). TBH I rarely use raw-plugs, expanding bolts, etc these days.

As has been said I really doubt you'd need to drill close to the edge anyway.

I wouldn't go into the mortar joint. Not a vertical one anyway. Not unless I knew the joint was properly bedded and not just pointed up. An SDS drill and a decent bit would have no problem with those blocks

 

[scholar]

I was going to suggest something similar to @Sgian Dubh above, except I was thinking of a full height lining to the reveal - depending on height/no of shelves, you could probably get away with 1/2” ply for the reveals.

(I would probably then go OTT with an architrave strip to cover any wonky gap.)

My workshop is full of holes for fixtures that have changed over time, so I now try to minimise these.

cheers

 

[Bristol_Rob]

I want to put up some shelves inside a window "bay" in my workshop. I plan on fastening a wooden cleat to the wall with two 5mm x 50mm screws, using 8mm rawlplugs drilled to a depth of 50mm. The shelf will simply sit on top of the cleat. Nothing fancy, after all it is a workshop. This photo shows the general arrangement, the wooden cleats will be about 200mm long.

View attachment 92810

Here's the question. The further apart the two screws the more stable the shelf. But if the front screw (ie the one furthest away from the window glass) gets too close to the breeze block edge then it risks blowing out. So how close to the edge should I drill?

My guess is 20mm, but does anyone have better advice? When I say "better" I mean not a guess, but advice based on industry guidelines, or at least on first hand experience!

Personally I don't drill in closer than 50mm from the edge.

 

[Mike Jordan]

I would favour the @Sgian Dubh solution but with a difference. Make the sides, top, and bottom out of 20 mm (minimum) thick solid material and then insert Tonk strips in the sides to give infinitely variable shelf heights and numbers to fit your needs. Only a few screws will be required to hold it in place and no,real load will be applied to them.