Correct way to drill into 'breeze blocks'

[Participant]

...if that's what they're still called:



I need to install some hanging racks and shelves in my garage for storage and to get things off the floor. When I've drilled holes in these before they've crumbled and left a hole too big for the intended rawl plug.

Is there anything special I need to know to do this properly, special fittings or plugs that work best with breeze block etc., or is standard rawl plug and screw the best way? Any drilling techniques to minimise crumbling?

To be fair the ones that crumbled were the ones in our interior walls that were built in ~1960, so maybe these will be fine .

Cheers!

 

[Schizo]

Just use normal wall plugs but use a smaller drill bit and work your way up.

 

[Participant]

OK cheers. Normal masonry drill bit without hammer action sound good?

 

[Schizo]

yup,as the blocks are quite brittle the hammer action will shake the block so a slow speed drill will be fine.

If you try drilling a block elsewhere for a trial run that will see how hard/brittle the blocks are,try drilling a trial whole somewhere down the bottom to see how it goes.

 

[Nightglow]

Aerated blocks, I tend to use these wall plugs, tend to grip a bit more, & I prefer to put them in a bit deeper,usually about 20mm below the the surface, less chance of lifting off the face of the block when you drive a screw in, & don't put plugs too near the edge of the blocks, they can easily split/ burst.

http://www.toolstation.com/shop/p24478

 

[Participant]

Sweet thanks both.

 

[Orionaut]

The old style breeze blocks were made of all sorts of old rubbish. (Ironwork "Sierra,Lima,Alpha,Golf" and ash mixed with cement was not uncommon)

As a consequence they were a mix of soft and hard materials. A drill would fly through the soft stuff and hit a bit of iron and shoot sideways creating the huge irregular holes that you remember!

Modern "Thermal Block" is an engineered and consistent material. It is fairly soft but you wont find any surprises drilling into it.

As has been said, You wont need hammer settings on the drill (Or even a masonry bit, a "Normal" drill will do the job just fine though you will wear it out with repeated use. Builders often cut these blocks to size using wood saws!)

I would be inclined to use larger screws/wall plugs (Diameter/length) since doing so will reduce the peak loadings on the relatively soft material (IYSWIM)

 

[Mark A]

Just screw straight into them with the yellow single thread screws. You dont need a plug, the screw thread will just bite into the block. I do this all the time when fixing skirting boards to breeze block walls in garage conversions.

Or these if there will be heavy items stored: http://www.screwfix.com/p/timco-con...tracking url&gclid=CKjQpsWfxLsCFWmWtAod_H8AoQ

You can try plugs, but they just spin the plug before tightening up for me.

 

[Orionaut]

Just screw straight into them with the yellow single thread screws. You dont need a plug, the screw thread will just bite into the block. I do this all the time when fixing skirting boards to breeze block walls in garage conversions.

I am sure that is fine for "Unloaded" fittings (Like skirting boards)

But would this really be strong enough for shelves??

I have seen screws designed specifically for doing this But have never been able to bring myself to trust them fully! (A bit like still being uncomfortable about aircraft manufacturers using Glue to stick the wings on their airliners! Even though I fully understand the science/engineering behind it! )

 

[DXP55]

I have had good results from using small knock in's - like frame fixings - drill hole with metal drill bit the exact size of the knock in and just tap them home - bit expensive thought

Like these but only 60mm long - they don't blow out the block

http://www.screwfix.com/p/rawlplug-...=Search-_-SearchRec-_-Area2&_requestid=124197

Found em http://www.toolstation.com/shop/Scr...er+Hammerin+Fixing+6+x+60mm/d90/sd1950/p65723

Dave