drilling breeze block for wall plugs - best practice?

[Icm76]

Is there a best practice for putting wall plugs into breeze block? I know some of the usual tips...

• drill using a bit one size smaller than usual.
• put some no more nails, grip fill, or something similar in the hole or around the plug if it's loose.
• make a larger hole than usual, fill, and then drill out the correct size once the filler is set.
• use resin fixings.

...is there a better solution?

This is an example of the stuff I mean, in case it's not really breeze block, or if it's known as something different these days?

• 

Whatever it's called, I've always found it to be quite inconsistent, some patches are very hard, solid and difficult to drill, other patches can be very soft and crumbly. Today was typical: brand new drill and brand new bit, first wall plug is a little loose, second one is perfect. The loose one will be easy enough to sort out, so I'm not worried about that.

[ayjay]

Is there a best practice for putting wall plugs into breeze block? I know some of the usual tips...

...is there a better solution?

Just practice: 99% of the time you only need to drill the correct size hole for a plug.

Not sure what the block is, it looks a bit like a concrete block, these should present no problems at all.

If you're going through plaster you cant see where the joints are so some holes may fall there, if the mortar is very soft you may have a problem or if the drill just catches the edge of a block, again you may have a problem. If your drill is not really up to the job it can mean that the hole becomes enlarged - there's a multitude of different things which can go wrong with fixing to brick/block but experience will sort them out. Resin fixings (except where required) or any other sort of filler should be a last resort.

Go a bit deeper and use a longer screw or stick two plugs in if one won't work, and don't use those awful short plugs that both TP and Jewson supply now, use a decent quality plug.

[Icm76]

Thanks ayjay. Stupidly I didn't think about the possibility of hitting the edge of a block or mortar, that may well explain the loose one.

Drill is a new Bosch SDS, and the plugs are Fischer (a mix of 6×50, 8×50 & 8×65, pushed though the plaster so they're fully anchored in the block.) I don't usually have too many problems with wall plugs, I think today I was just a bit too casual about it and expected everything to be a doddle because I have new toys.

[cotswold builders]

Try drilling on a slow speed and if possible without the hammer on, those blocks have a lot of large aggregate in them, and going to fast can make the drill bit wander, ie when it hits a large solid aggregate the drill bit will slide, keep a firm level pressure.

[Razor]

You also need to use decent plugs in these walls, something like Screwfix item 22190

Can't post proper links from the wallyphone

[Job and Knock]

Another issue might be drill chuck concentricity or drill straightness. Drill soft blockwork or bricks with a wonky drill or chuck and the hole will always end up too big

[jozeffo]

Drill holes with a 6mm bit, but have both 6mm and 7mm plugs to hand so that if there is alot of breakout, you use the larger ones and if there isn't you use the smaller ones.

[Icm76]

Thank for the responses - some good tips posted. I was premature in posting this thread as ayjay was spot on re the mortar, I should've looked at properly. The new drill and bits are fine, all the subsequent plugs have fitted cleanly into the correct size hole.

You also need to use decent plugs in these walls, something like Screwfix item 22190

I'm using a mix of Fischer UX and SX plugs, though not from Screwfix, I got mine from Tooled-Up. The Fischer Universal plugs that Screwfix have are the UX R type - they have a collar that is supposed to stop the plug slipping into the drill hole. However I wanted the ones without the collar so that they can more easily be knocked through the plasterboard and fully fixed into block. I also got some of the longer SX L for extra security with heavier loads. Product pages for both types:

• Fischer UX universal wall plugs
  Fischer SX wall plugs