Yet Another Cycling Forum

General Category => The Knowledge => OT Knowledge => Topic started by: TimO on 01 April, 2024, 06:35:57 pm

Title: Drilling holes into plastered brick walls
Post by: TimO 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?
Title: Re: Drilling holes into plastered brick walls
Post by: Jurek 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
Title: Re: Drilling holes into plastered brick walls
Post by: rogerzilla 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.
Title: Re: Drilling holes into plastered brick walls
Post by: TimO 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.
Title: Re: Drilling holes into plastered brick walls
Post by: TimO 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.
Title: Re: Drilling holes into plastered brick walls
Post by: Jurek 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.
Title: Re: Drilling holes into plastered brick walls
Post by: robgul 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.
Title: Re: Drilling holes into plastered brick walls
Post by: Jaded on 01 April, 2024, 07:14:27 pm
Also check the quality and sharpness of your bits.
Title: Re: Drilling holes into plastered brick walls
Post by: rogerzilla on 01 April, 2024, 07:23:28 pm
Also check the quality and sharpness of your bits.
/rogerzilla heads for the bathroom
Title: Re: Drilling holes into plastered brick walls
Post by: TimO 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. :)
Title: Re: Drilling holes into plastered brick walls
Post by: Russell 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.
Title: Re: Drilling holes into plastered brick walls
Post by: Blodwyn Pig 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....:)
Title: Re: Drilling holes into plastered brick walls
Post by: Von Broad 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
Title: Re: Drilling holes into plastered brick walls
Post by: Polar Bear 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. 
Title: Re: Drilling holes into plastered brick walls
Post by: freeflow 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.
Title: Re: Drilling holes into plastered brick walls
Post by: chrisbainbridge 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!!
Title: Re: Drilling holes into plastered brick walls
Post by: mrcharly-YHT 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/ (https://www.bosch-professional.com/ao/en/expert-sds-max-8x-hammer-drill-bits-2867203-ocs-ac/)
Title: Re: Drilling holes into plastered brick walls
Post by: telstarbox 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?
Title: Re: Drilling holes into plastered brick walls
Post by: Tim Hall 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.
Title: Re: Drilling holes into plastered brick walls
Post by: Russell 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.
Title: Re: Drilling holes into plastered brick walls
Post by: Blazer 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
Title: Re: Drilling holes into plastered brick walls
Post by: jsabine 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.
Title: Re: Drilling holes into plastered brick walls
Post by: TimO 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.
Title: Re: Drilling holes into plastered brick walls
Post by: TimO 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 (https://www.youtube.com/watch?v=oC6BuUkWQ48) 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.
Title: Re: Drilling holes into plastered brick walls
Post by: mrcharly-YHT 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.
Title: Re: Drilling holes into plastered brick walls
Post by: Jurek on 04 April, 2024, 09:05:23 am
I was curious about what was considered a good brand for drill bits, and found this video (https://www.youtube.com/watch?v=oC6BuUkWQ48) 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.
My bold
When I was still working for the Museum, we considered De Walt power tools as 'one-way' tools when we were doing installations overseas.
Title: Re: Drilling holes into plastered brick walls
Post by: TimO on 06 April, 2024, 10:28:48 pm
A cursory search suggests that some DeWalt products are OK, but it does seem a bit random. Bosch on the other hand, fairly universally does well.

Most of my power tools are either Bosch or Parkside, so I cover the two extremes, and I'm fairly sure I've never owned anything more expensive from DeWalt than drill bits, so don't really have much of an opinion about them. :)
Title: Re: Drilling holes into plastered brick walls
Post by: fruitcake on 07 April, 2024, 08:57:52 am
AIUI Dewalt was primarily  a woodworking tool firm  (or it grew from a woodworking tool firm). I guess their designs were focussed on that material and their customers were mainly working with wood. That is a simplification, but perhaps there's something in it.

Nonetheless the carpenter/joiner tradesman we know uses Makita which he considers better for joinery. Makita tools I've seen in shops are the more expensive of the brands.

Bosch was always an engineering firm across multiple sectors, and is a wealthy corporation with huge resources for product development, so I'd expect their stuff to 'just work'.

In an age of battery power tools, each brand produce systems of tools that share a common proprietary battery, and so consumers will stick with one brand. (A strategy of non-compatibility with other brands is also used by DSLR camera manufacturers and bike component manufacturers.)

I have no brand loyalty.
Title: Re: Drilling holes into plastered brick walls
Post by: Kim on 07 April, 2024, 01:18:29 pm
That's less of a thing than it used to be, as you can get adaptors from one manufacturer's battery to another.  There's also some work going on to standardise batteries across the more niche manufacturers.  I suppose if you're in the business of making plaster stirrers there are only advantages to using the same batteries as $vacuum_pump_manufacturer and $glue_gun_manufacturer.
Title: Re: Drilling holes into plastered brick walls
Post by: Jurek on 07 April, 2024, 01:29:12 pm
DeWalt bought Elu.
They pushed yellow plastic through Elu's injection moulding tools, removed half of the windings from the motor, and replaced the 9v battery with an 18v one.
My 9v Elu cordless would knock spots off a DeWalt 18v equivalent.
Title: Re: Drilling holes into plastered brick walls
Post by: robgul on 07 April, 2024, 04:10:26 pm
DeWalt bought Elu.
They pushed yellow plastic through Elu's injection moulding tools, removed half of the windings from the motor, and replaced the 9v battery with an 18v one.
My 9v Elu cordless would knock spots off a DeWalt 18v equivalent.

. . . and Black & Decker owns de Walt from what I can see . . . .  not sure if that's good or bad?
Title: Re: Drilling holes into plastered brick walls
Post by: mrcharly-YHT on 07 April, 2024, 05:07:53 pm
Bosch blue is good.

Bosch green isn't much better than black and decker these days.

Old bosch green was decent.
Title: Re: Drilling holes into plastered brick walls
Post by: TimO on 08 April, 2024, 12:43:31 am
That's less of a thing than it used to be, as you can get adaptors from one manufacturer's battery to another.  There's also some work going on to standardise batteries across the more niche manufacturers. ...

As you say, adapters are fairly easily available. The only attempt at standardisation I've seen, is the Cordless Alliance System (CAS) (https://www.cordless-alliance-system.com/), however at best I've barely heard of most of them. Metabo is about the only name that I'm sure I've seen before! As you say, many of them make relatively niche products; "GESIPA develops and manufactures blind rivets and nuts, as well as setting tools. ...".