Perception of the hardness of brick is often at variance with reality

[Bill Wright]

Listen to any DIY man and he will tell you about the extraordinary hardness of the bricks that make up his house. If you were to take these complaints at face value you would believe that most British houses were made from bricks that were second only to diamond on the Mohs scale. "You're going to drill right through the wall? You'll have a right job! These bricks are very hard! Very very hard! Hardest bricks there is! Don't ask me why they used such hard bricks!"

This belief stems from the use of non-SDS electric drills that have only a ratchet hammer action. Such drills are very inefficient when drilling masonry.

It is more comfortable to claim that the bricks are exceptional than to accept that the drill, and by extension yourself, are inadequate. Who wants to go into the house and tell the wife that his tool isn't up to the job? Thus the myth of hard bricks persists.

Bill

[Brian Gaff]

There is of course Murphy's law as well, no matter where you want to drill a major hole in a wall, at least one brick will be.. so hard that all the mortar falls out before you get done So naff it crumbles to dust or. No matter how careful you are on the inside, a wedge of plaster is released and only held up by the wallpaper.

Brian

[dennis]

They exist but they don't usually build houses from them. But, I have never tried to drill blue engineering bricks with bosh multi material drills yet. Maybe they go through them like butter, they do through most other stuff, without turning on the hammer action or even changing from a battery drill.

[Graham.]

By that logic brick must have got softer some time in 1975 when "Steck Dreh Sitz"* drills became available.

*In the absence of JGM, I have promoted myself to Chief Googler.

[John Rumm]

The person who wants to justify the purchase of a shiny new toy to the Mrs. ;-)

Indeed...

(although I was cutting some solid blue engineering bricks in half the other day, and the diamond disk on the 9" grinder was glowing red hot at times! That actually took some doing, when normally it would laugh in the face of a normal brick).

[The Medway Handyman]

There is a small group of houses in Brompton, very close to the dockyard which were built by (or on behalf of) the RN.

They are cement rendered engineering bricks. I frequently get called out to hang pictures, TV's, mirrors etc because a normal masonry drill has no effect whatsoever - apart from eventually glowing red.

[Richard Russell]

Not me. Our last house was built entirely from engineering bricks (it was a temporary foray into house building by a company - Websters - who usually built commercial premises) and they genuinely were very hard. Our current house is the opposite extreme, soft red bricks that almost seem to visibly erode in the wind!

Bricks are very variable. Sweeping generalisations are not helpful, either about bricks or about DIYers!

Richard.

[Andy Champ]

Coincidentally this weekend I was drilling a couple of holes into the wall of my son's place. Unfortunately I hadn't brought my drill with me. Luckily in the bottom of my toolbag was an old rawldrill set my grandfather left me - it seemed to work just fine. (though only two holes!)

Andy

[SteveW]

When we eventually move, the next residents may find the walls of our conservatory a bit hard to drill through if they want to put a cable in. The closest visual match to the back of our house was an engineering brick.

SteveW

[Tim Lamb]

As a just transferred 11 year old, the height of fun on a winter mornings break was boring holes in the practical centre red brick walls with a copper penny.

A year later it was cotton reel tanks! Anyone remember those?

regards

[Peter Duncanson]

Oh, yes.

[Martin]

when I was about 8 or 9.

and throwing red hot pennies out of the window of the metal work workshop for little boys to pick up? This progressed to dropping plastic bags full of water from the first floor window.

[Ian Jackson]

In message , Martin writes

When I were a lad, plastic bags didn't really exist. We had to make do with rubber balloons. [I suppose condoms would have worked too!] Unfortunately, the group of school prefects on whom we chose to drop our water bombs were not amused!

[R. Mark Clayton]

Walls are made of various grades of bricks and their hardness varies: -

Engineering bricks - usually purple. Very strong [obviously] and I guess very hard.

Facing bricks - usually smooth - more vitrified - very hard.

Common bricks - quite hard

Concrete brick - fairly hard, but not as hard as common bricks.

Breeze block - fairly soft.

Thermalite (foamed concrete) blocks - very soft.

B&Q sell anchors which you screw into the last two as normal rawl plugs etc. tend to pull out.

The most difficult thing I have tried to drill is a cast in situ concrete lintel in my flat. I don't know what the aggregate was, but we burnt out my spark's professional Bosch hammer drill and only went ~10cm in 10 minutes. Took the wires another way in the end...

[Ian Jackson]

In message , R. Mark Clayton writes

My house was built in 1954. The bricks are incredibly hard, and I've always understood they were engineering bricks. The 'mortar' is often even harder (essentially concrete). Drilling with an ordinary domestic hammer drill is a Herculean task. Masonry nails, cable clips etc are absolutely impossible to hammer in, the only way to use them is first to painstakingly drill a hole, and insert a small Rawlplug.

In contrast, the bricks of a recent small extension are incredibly soft. Here, masonry nails etc need Rawlplugs because the brick tends to crumble as you knock them in, and they are not held firmly. The consistency of mortar is not unlike the sand you make seaside sandcastles with - and masonry nails also need careful Rawlpluging.

[The Natural Philosopher]

The standing joke in the bricklaying trade is whether mortar is there to hold the bricks together or to keep them apart.

If you consider the history, bricks were essentially replacement for stone blocks and or mud blocks, and sand was used to pack the gaps: Adding lime to the sand sort of crusted it a bit, so it didnt wash out. Likewise firing mud bricks meant they didn't wash away either,.

the modern habit of hard mortar is actually quite short.

[John Rumm]

My previous place of similar vintage also had a fairly hard brick (although a common brick, not an engineering) and render. A normal masonry bit would not touch it. However a Bosch multimaterial bit would do the job in a conventional hammer drill. The SDS had no trouble with it obviously.

[Huge]

Never seen an origami water bomb?

[Martin]

[Huge]

"When I were a lad, plastic bags didn't really exist."