Author Topic: Drilling holes into plastered brick walls  (Read 2322 times)

Drilling holes into plastered brick walls
« on: 01 April, 2024, 06:35:57 pm »
My house is moderately old, just over a century, and it's constructed of solid brick walls with plaster over the interior of those walls.

From time to time, I find myself needing holes in the walls to mount things, and it never goes very well. Some of the holes go in easily, but others drift off, and often I end up with an excessively large hole, so I have to either move and re-drill the holes. or bodge it by partially filling the holes with something else, like pieces of wood.

Mostly this works, but it slows things down, and I'll often have to put an excessive number of holes in for heavier items, and use more mounting points than would seem necessary, as some mounts end up a bit 'iffy', to use a technical term!

Searching for solutions online, the best suggestion I've found is to just drill a lot of small holes, to find the lines of mortar, and then space the holes so that they're in the middle of bricks. I guess this would work, but is going to be tedious, won't always work for the spacing of some attachment points, and will go wrong where there isn't a simple contiguous stretcher bond.

I'm sure plenty of other people have similar problems, so there must be some sort of relatively straightforward solution? The best additional help I can think of, is some sort of quick setting epoxy or filler, that could go into any accidentally large holes, and once set would provide a location to re-drill more easily, a better hole. I've had a search for anything, but nothing obvious came up, beyond traditional 'polyfiller' plaster type materials, which take a long time to set, and may possibly be fair weaker than the original wall.

I've had exactly the same problem with both large holes using expanding strong metal mounts, as well as much smaller plastic 'rawlplug' type fittings.

Any thoughts?
Actually, it is rocket science.
 

Re: Drilling holes into plastered brick walls
« Reply #1 on: 01 April, 2024, 06:41:56 pm »
I've been successfully using these forever:
ETA : Pre -drill a pilot hole (using a non-masonry/sacraficial bit) of the same diameter as the unthreaded part..
~8mmØ or thereabouts.

https://www.screwfix.com/p/easyfix-self-drill-plasterboard-fixings-metal-32mm-100-pack/2422H?tc=VT6&gad_source=1&gclid=CjwKCAjwtqmwBhBVEiwAL-WAYeXt1224rUe-Vny4Bqe7GMZy8AOmkXbCICiHiFnMju4fAR_SndZ-CxoC9yIQAvD_BwE&gclsrc=aw.ds

rogerzilla

  • When n+1 gets out of hand
Re: Drilling holes into plastered brick walls
« Reply #2 on: 01 April, 2024, 06:47:40 pm »
Start drilling at slow speed, without hammer action.  When you have a decent hole, switch to hammer.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Re: Drilling holes into plastered brick walls
« Reply #3 on: 01 April, 2024, 06:50:28 pm »
I've been successfully using these forever:
ETA : Pre -drill a pilot hole of the same diameter as the unthreaded part..

https://www.screwfix.com/p/easyfix-self-drill-plasterboard-fixings-metal-32mm-100-pack/2422H?tc=VT6&gad_source=1&gclid=CjwKCAjwtqmwBhBVEiwAL-WAYeXt1224rUe-Vny4Bqe7GMZy8AOmkXbCICiHiFnMju4fAR_SndZ-CxoC9yIQAvD_BwE&gclsrc=aw.ds

When I lived in a house with thick plasterboard walls, that sort of thing worked well, and was nice and easy! Would it really work in plaster, and then into bricks/mortar? The plaster doesn't seem to be particularly thick, solid or robust, some of it may be very old, and my gut says that when I tried to screw that in, a lot of the plaster could possibly just fall away.
Actually, it is rocket science.
 

Re: Drilling holes into plastered brick walls
« Reply #4 on: 01 April, 2024, 06:53:12 pm »
Start drilling at slow speed, without hammer action.  When you have a decent hole, switch to hammer.

Into the plaster, I don't need the hammer anyway, and often into brickwork it isn't always necessary. The trouble often is, that if the hole is in or near the mortar the drill hole will drift anyway, and the resulting hole can be weirdly shaped and too large, so the intended fitting won't work, without filling the hole with something else, and a final fixing which isn't as secure as I'd like.
Actually, it is rocket science.
 

Re: Drilling holes into plastered brick walls
« Reply #5 on: 01 April, 2024, 06:57:39 pm »
I've been successfully using these forever:
ETA : Pre -drill a pilot hole of the same diameter as the unthreaded part..

https://www.screwfix.com/p/easyfix-self-drill-plasterboard-fixings-metal-32mm-100-pack/2422H?tc=VT6&gad_source=1&gclid=CjwKCAjwtqmwBhBVEiwAL-WAYeXt1224rUe-Vny4Bqe7GMZy8AOmkXbCICiHiFnMju4fAR_SndZ-CxoC9yIQAvD_BwE&gclsrc=aw.ds

When I lived in a house with thick plasterboard walls, that sort of thing worked well, and was nice and easy! Would it really work in plaster, and then into bricks/mortar? The plaster doesn't seem to be particularly thick, solid or robust, some of it may be very old, and my gut says that when I tried to screw that in, a lot of the plaster could possibly just fall away.
My bold.
Suck it and see.

robgul

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Re: Drilling holes into plastered brick walls
« Reply #6 on: 01 April, 2024, 07:03:59 pm »
I would steer of messing with epoxy etc.

My take would be to drill a small-ish pilot hole with a masonry/multi-purpose bit (with hammer if necessary) but slowly (very slowly) and then drill with the size drill bit you need for the fixing.   

I've always had success with Fischer fixings on a variety of old brick and stone buildings, usually with a longer than necessary plug and screw for whatever I was hanging.

Jaded

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Re: Drilling holes into plastered brick walls
« Reply #7 on: 01 April, 2024, 07:14:27 pm »
Also check the quality and sharpness of your bits.
It is simpler than it looks.

rogerzilla

  • When n+1 gets out of hand
Re: Drilling holes into plastered brick walls
« Reply #8 on: 01 April, 2024, 07:23:28 pm »
Also check the quality and sharpness of your bits.
/rogerzilla heads for the bathroom
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Re: Drilling holes into plastered brick walls
« Reply #9 on: 01 April, 2024, 07:33:08 pm »
I started off with a brand new mortar bit today, and about half of the holes have been damn near perfect, with the other half going badly or very badly wrong!

I'm mounting about 8 plastic panels, with a screw hole at each corner, and they only need a 4mm hole, but the ones that go wrong are taking me far longer to sort out than the perfect ones. With 32 holes, it just gets a bit annoying when however careful I am, sometimes it all goes wrong.

My previous plaster-boarded house was far easier, and the job would have been all sorted out a while ago. :)
Actually, it is rocket science.
 

Re: Drilling holes into plastered brick walls
« Reply #10 on: 01 April, 2024, 07:34:48 pm »
Use an SDS drill.  I bought a Lidl Parkside for about £50 and it is miles better than a hammer drill.  Start small and open up as necessary.  The SDS means drilling is easier and you have more control.

Blodwyn Pig

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Re: Drilling holes into plastered brick walls
« Reply #11 on: 01 April, 2024, 07:38:05 pm »
well, considering bricks are almost 9"x 3", and surrounded by mortar that is prob 1/2" thick, you must be very unlucky to keep missing them. don't take up playing darts , will you....:)

Re: Drilling holes into plastered brick walls
« Reply #12 on: 01 April, 2024, 07:53:27 pm »
Use an SDS drill.

SDS drills are great but be careful about using them in old houses, you can easily end up demolishing the entire house :-)

So often, once you've decided where you want to hang/mount something on a wall then the position has been decided and you have to do what you can [if it's a kitchen cabinet or the like, sometimes you have no choice where the position will be].


I've lost count of the number of times I've gone to attach something in an old house, only to find I'm drilling into old mortar turning to dust. The only thing I'm happy doing is making the hole that big to get rid of the old mortar, vacuuming out all the dust, liberally wetting the hole with water [bit of PVA mixed in if you fancy], mixing up a bit of filler.....anything really - decent filler, bonding plaster, finishing plaster, inserting your plug in the filler and letting it set before you get screwing. It's a bit of faffing about, but it's not too much trouble, and providing you get the filler adhering to some brickwork, you'll get a good fix every time.

edit: just re-read your post, you've obviously been doing something like this, but the key to it, is get rid of the old mortar and residual dust, get back to brick and put some decent filler in there....plaster, mortar mix etc
Garry Broad

Re: Drilling holes into plastered brick walls
« Reply #13 on: 01 April, 2024, 07:59:35 pm »
Use an SDS drill.  I bought a Lidl Parkside for about £50 and it is miles better than a hammer drill.  Start small and open up as necessary.  The SDS means drilling is easier and you have more control.

Indeed.  I bought one a number of years ago for £29 fully expecting it to expire relatively quickly but hoping for long enough to decide on a decent SDS drill or not.

Bloody thing is still going.  Easily the best drill that I have ever had for drilling holes into brick and concrete. 

Re: Drilling holes into plastered brick walls
« Reply #14 on: 01 April, 2024, 08:06:36 pm »
At the centre (hidden part) of the item you wish to fix drill very narrow holes (~1mm) and look for the colour of brick dust, then drill similar holes at 1 cm spacing up and to the right but only to the depth of the plaster so you can check if you hit brick or mortar.  You might need to use a wet wipe to clean the bit between holes so you can be sure that the colour of the dust represents the current hole.  Based on you knowledge of the brick dimensions and how many holes you drill you should be able to estimate where your holes should go to drill into brick.


When you drill your final holes use multiple bits at 1mm or 0.5 mm increments until you get to the size you need.


Use a peice of tape wrapped around the drill bit for the exploratory holes so you don't drill too deep.
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Re: Drilling holes into plastered brick walls
« Reply #15 on: 01 April, 2024, 09:54:23 pm »
We have a 1950s house currently with very hard plaster, rounded corners and all. My policy is small bits through plaster and settled into the brick  or mortar and then open up sequentially. Throw bits away regularly.

Slow with no hammer lets the bit get started then adding the hammer speeds up the process. Doubling the size of fixing always helps!!

Re: Drilling holes into plastered brick walls
« Reply #16 on: 02 April, 2024, 08:44:02 am »
There are bricks, and there are bricks.

Some bricks have hard clinker parts; the drillbit hits those, does a big 'nope' and wanders.

Good quality bits help.

Starting with a smaller bit can help - more chance of getting through the hard bit and less wander.

Very large holes in brick (which can happen when bits wander, the brick decides to split . . .) can be coped with by tapping in a chunk of softwood; not all solutions need to be high-tech!

If you have to do lots of drilling in masonry, these bosch bits are the dog's danglies:
https://www.bosch-professional.com/ao/en/expert-sds-max-8x-hammer-drill-bits-2867203-ocs-ac/
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telstarbox

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Re: Drilling holes into plastered brick walls
« Reply #17 on: 02 April, 2024, 10:10:52 am »
A related query - my friend has a recent new build flat and we were trying to install a curtain pole above a fully glazed window (this is the external wall of the building)
The end supports went in fine with rawlplugs but we couldn't get the central support to hold in the same way. Any idea what the material might be made of here?
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Tim Hall

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Re: Drilling holes into plastered brick walls
« Reply #18 on: 02 April, 2024, 10:20:55 am »
A related query - my friend has a recent new build flat and we were trying to install a curtain pole above a fully glazed window (this is the external wall of the building)
The end supports went in fine with rawlplugs but we couldn't get the central support to hold in the same way. Any idea what the material might be made of here?
There's likely to be a steel or concrete lintel in there - a sort of beam taking the load of the wall over the gap made by the window. If it's a steel lintel I suspect you could use a suitable drill bit for steel plus self tapping screws. Concrete should be drillable with a sufficiently good hammer or SDS drill and sharp bit.

Alterenatively fix a timber batten, supported at the ends where you can get a screw in, then fix the blind to that. Depends a bit on the width of the window.
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Re: Drilling holes into plastered brick walls
« Reply #19 on: 02 April, 2024, 11:14:51 am »
Agree with Tim, lintel of some sort.  Bosch make a multi material drill with blue flutes (CYL-9) that drills through anything, steel included.

Blazer

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Re: Drilling holes into plastered brick walls
« Reply #20 on: 02 April, 2024, 01:56:43 pm »
I find similar to OP. The issue appears to be small aggregate between the finish plaster and the brick.

Hit a small pebble and that's it, small hole in the right place becomes big hole before you even reach brick.

The plaster and bond to the brickwork is also not great given the age of the building.

Resin filler saves the day

Re: Drilling holes into plastered brick walls
« Reply #21 on: 02 April, 2024, 09:44:40 pm »
Bosch multi-material bits are excellent - or at least were when I was doing this sort of thing for a living ~15 years ago.

And yes, self-tappers work well in a steel lintel.

Re: Drilling holes into plastered brick walls
« Reply #22 on: 03 April, 2024, 12:10:51 am »
Ultimately, for this round of hole drilling, a better quality (DeWalt) masonry bit helped, although I still got some wandering. As some have said, I suspect there were some larger and harder fragments in both the bricks and the mortar. Drilling into neither appeared to be entirely consistent.

I may experiment with Jurek's suggestion of using metal plasterboard fixings when I next need a series of small(ish) fixings.
Actually, it is rocket science.
 

Re: Drilling holes into plastered brick walls
« Reply #23 on: 03 April, 2024, 11:14:34 am »
I was curious about what was considered a good brand for drill bits, and found this video on YouTube, comparing masonry bits. Project Farm does a lot of these sort of comparison videos on tools and workshop consumables, and generally do a reasonable job. The main problem is that it's a USA channel, so sometimes the brands they mention do not exist in the UK, or are excessively expensive compared to the USA (due to rarity and postage).

It's interesting to see, that ultimately he found the Irwin, Diablo ,Milwaukee, and Bosch parts to be the best. A little surprisingly, the DeWalt bits didn't do very well at all (so of course I've got a few of those!)

You can find all of those 4 brands available for delivery to the UK, but the Diablo are harder to find, relatively expensive due to delivery, and often only available in imperial dimensions not metric.

Bosch are probably the easiest to find (not surprisingly), and a cursory search suggests they're not noticeably more expensive than the others, and sometimes possibly cheaper! Since many in this thread have highlighted Bosch, I think in future I'll aim to use their bits.
Actually, it is rocket science.
 

Re: Drilling holes into plastered brick walls
« Reply #24 on: 03 April, 2024, 12:43:01 pm »
It is specifically the multi-tip Bosch that are outstanding (all their bits are good quality though).

The shape means they are less prone to diverting and they cut very fast.
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