masonry drill length

[ban-all-sheds]

Start looking on eBay for a good used corded SDS+ drill, of a proper make/range, at about 5J, such as blue Bosch, Makita, Hitachi.

 

[mwatsonxx]

This seems like a 'one off' job. Much simpler and cheaper to use a tool hire shop, he'll get the correct tools for the job.

 

[ban-all-sheds]

It's always a one-off job. Until the next one-off job, and the one after that.

As well as holes through walls for cables I've used my Bosch GBH-4 for small-scale demolition/breaking, cleaning reclaimed bricks, cutting a hole for a tumble drier exhaust duct, chopping out for back boxes and simply drilling 6mm holes in particularly recalcitrant concrete lintels to put up curtain tracks.

 

[ban-all-sheds]

hi, can anyone tell me the length of masonry bit i need to buy, to drill from outside a wimpy brick house to get through the 2 bricks to make a big enough hole for a cable & best bit to get through ,cheers

Effort-saving tip:

It will depend on what size cable you need to get through, but what I've done for lights in the past is to use 16mm flexible conduit. You really need an oversized hole - 20mm conduit through a 20mm hole is an unnecessary struggle (probably why flameport recommended a 22mm bit).

With 16mm conduit you can use an 18mm or 20mm bit.

And I would recommend working up in a number of small steps, to minimise spalling.

 

[EFLImpudence]

Do 20mm. bits drill exactly 20mm. holes in masonry?

They always seem to end up a bit larger in my experience.

 

[JohnW2]

Do 20mm. bits drill exactly 20mm. holes in masonry? They always seem to end up a bit larger in my experience.

And, for what it's worth, also in my experience (and, obviously, not just 20mm ones!).

Kind Regards, John

 

[John D v2.0]

I needed to put some 10mm2 SWA through a cavity wall, I found by reading the specs that the swa was about 15.8mm diameter (or somesuch), the plastic conduit was 20 with a 2mm wall thickness, and in the end the conduit fitted perfectly through the wall with a hammer tap, and the swa fitted snugly in the conduit enough to draw enough length to reach the under stairs cupboard.
I also used the same type of conduit to protect a 15mm copper water pipe passing through the cavity. And some t&e for an outside light which needed protecting from the polystyrene insulation.
But I think the eventual size of the hole depends also what you're drilling through and the quality of the bit.

I think the OP will be confused now, the amount we're all contradicting each other!

 

[crooner]

update ,
hi, tackled the drilling this evening used my bosch 680 limited to masonry 14mm
bought a quality PTX universal 16mm bit from B & Q & took my time,
got through what was only one brick about 5" without too much trouble
so thanks to all for your input