# Forum Home Renovation Brickwork  Drill/Bit selection

## bobfloyd

Hi Guys, 
I'm fitting a 100 x 50 spotted gum ledger board to brick. 
I'll be using 10 x 100 Ankascrews, every 450mm. 
I intend to dril 70mm into the brick (50 through the ledger board, 50 into the brick, and the extra 20 per Ramsets guide). 
So I presume that means need a 10 x 120 masonry bit - correct? 
Do I need to drill a smaller pilot hole first, or am I right to take to the bricks straight up with the 10mm bit?   
The house is 20 years old, so they are the usual 6 hole bricks (or they might be 3 hole, I'm not sure). 
What are the Kango bits at bunning like?  e.g.  Kango 10mm x 120mm Straight Shank Masonry Bit I/N 6350314 | Bunnings Warehouse 
Is there any option here for me to use a regular drill with a non-hammer masonry bit?  Hammer feature will make the job faster right? 
Just pull the bit out, don't press too hard?  No need for oil/water cooling? 
Obviously I haven't drilled through brick before.   :Redface: ) 
Cheers.

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## GeoffW1

Hi, 
Yes, 10 x 120mm masonry drill looks good, to allow for debris left in the bottom of the hole, and therefore sufficient extra room for tightening the bolt.  
I'd use a pilot masonry drill first, 3-4mm. It does not need to be full depth, just 40mm or so to keep the 10mm drill on target. Larger bits have a tendency to wander off when starting. 
You will definitely need a hammer action. You will be there forever with a normal drill, some bricks are quite hard. No water etc is used, the drill point does not need it. And yes, you do need to press hard, the dynamics of these drills depend on firm contact at the bottom of the hole, plus regular backing out the clear the dust. The flutes of a masonry drill don't extract debris efficiently enough. 
Don't forget the ear protection. 
Cheers

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## LordBug

If you can afford to, I'd also grab a bit the closest size down, and then do some test drills in a spare brick or two.
In my walls, the recommended bit for the bolts has been fine in some spots, some other spots the brick/mortar has been a bit soft, so the recommended bit made the hole larger than useful. If I'd used a size down, it would've saved me frustration, and it's quick enough to enlarge with the recommended bit if the fit is tight. Luckily, the application wasn't that heavy, so I was able to use (dodgy alert!) whipper snipper cord as plug spaghetti, still holding up fine two years on  :Smilie:  
Also, when starting the hole, I always like to use regular drill mode to get the hole straight, and when it stops progressing quickly (if going through plaster/render) or has a nice little guid hole (naked brick) then I switch to hammer mode.

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## chalkyt

Yep, LordBug has alerted to a common problem of holes ending up bigger than you expect. It sounds as though your bricks are the extruded type i.e they are made from wet clay, squeezed out continuously like toothpaste, cut off, then dried and fired. Because of the extruding process they have holes through them which gives the mortar something to key into. Older "conventional" dry press bricks don't have holes they have a frog (depression) to give the mortar a key. The extruded bricks present two problems for your type of job...
1. They tend to be somewhat hard and brittle and drilling can break the web between holes or the back of the brick away when the drill emerges if you apply too much pressure, leaving you without much brick to hold the fastener (and without your special x-ray goggles it is hard to tell if this has happened..
2. If you drill through the holes it may not suit the type of fastening you are using. This can be a real problem with something like dynabolts (which you aren't using) or can leave you without enough meat for ankascrews to bite into if you have blown the web or back out of the brick (which you may not even know about). Even with a clean hole an ankascrew will bite into say 30mm of brick, then air if you have drilled into a hole then ??? air or brick depending on if you have pushed the back out of the brick or the web between holes. 
Sorry to frighten you with potential disasters but sadly this is based on experience and it can be very frustrating and time consuming to overcome... the point being to take care when choosing the type of fastener and where you drill the holes. Have a look to see if they are three or six hole bricks and where the holes are, then determine the best type of fastener to use.

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## phild01

:Arrow Up:  yes, this is a typical issue.  Have you considered using threaded rod and a chemset.  Would need compressed air to blow holes out and is more expensive.

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## shauck

or.... can you avoid all together and use stump holes and bearer? Joists can cantilever a bit so your stump holes can be situated well.

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## bobfloyd

Cheers for all that info guys. 
 I was going to prill-drill the ledger board (12mm) and then use that as a guide for the masonry bit, so I guess I don't need the pilot hole so much to stop it wandering (familiar with that in timber), but more to make the 10mm drilling easier. Should I still use the smaller bit first?  
 Thanks for the tip regarding the hole ending up a bit bigger, that thought had actually occurred to me at one point. I guess start with the 10mm in test brick, drop down to a 9mm, or 8mm...actually....better just to start all holes with the 8 I suppose...   
 I'll suss out exactly what bricks they are. I wonder if it would be better to "aim" for the holes, or the web between the holes? Aiming for the holes means less "meat" for the ankascrew, whereas aiming for the web might break it?  Before drilling the holes in the ledger, I could put the ledger against the wall and make marks on the ledger where to drill, so that the hole ends up lining up nicely with the preferred part of the brick.  
 Is the 450mm spacing ok, or can I space them further apart that this?  Whatever the minimum spacing, if I make it a multiple of brick + vertical mortal length, I suppose I'll always be in the preferred spot of a course of brick (as long as it doesn't clash with a joist hangar, but I can work around that).  
 Putting stumps here is not an option; too high risk of hitting a pipe.  I was going to do that but decided to stay above ground here.   
I can't "damage" the structural integrity of the house here though can I?  Lot's of people it ledger board to brick for  a low level deck without issue...?  
 Cheers guys.

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## phild01

I have 3 holed bricks and there is some inconsistency with the hole spacing.  Some bricks used today are so full of air I wouldn't even consider using an expanding or screw style fixing.
Aim for the solid areas.  I find starting with a smaller drill first makes drilling easier and better.  You are using a hammer drill which is fine, a rotary hammer can break the brick.
450 is good.

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## bobfloyd

Another quick thought - so those holes are just used for "keying" the mortar?  The holes don't actually end up full of mortal? 
Some people seem to deliberately aim for the motar....surely not aiming for the mortar would be better?  Wouldn't the mortar be more likely to crumble out than the brick, or does that just depend on the type/age etc of the mortar? 
Cheers.

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## phild01

The fixings should not go into the mortar as you suggest.  It is too soft.  The brick voids are not intentionally filled with mortar.

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## bobfloyd

This brick wall is a wall that runs down below ground level, it is not a timber veneer wall.  So it's a supporting wall made up of brick and brick pillars every 1800 or so.  Due to it's use as a supporting wall, would this mean the holes in the brick need to be filled, or is it possible there could be steel rods running down inside the holes? 
I guy here at my work suggested for aiming for just off the edge of the brick (I..e in between edge of brick and first hole). 
Cheers.

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## chalkyt

As above, dodge the mortar between bricks as it sometimes doesn't fill the space between the brick end faces and is often quite soft. If you watch a brickie at work, you will see that the mortar is buttered onto the front and back side edges of the brick and so doesn't always meet in the middle. The holes in the bricks are unlikely to be filled. steel rods are commonly inside block walls... don't know that I have ever struck them in brick. The guy at work is probably right as long as there is enough distance between the end of the brick and the hole. There is always the risk of breaking out the end of the brick of course. If it was easy, we would all give you the same answer!!! 
Dry pressed bricks (actually made from only slightly damp clay and machine pressed together before firing) are much easier to work with as they are solid but quite rare in newer buildings.

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## chalkyt

Just stumbled across one of the extruded bricks used on my place. Interesting... it has two rows of five holes which means that drilling in the centre of the brick would put you through the holes. There is 15-20mm of "meat" between holes but only about 12mm from the end of the brick to the edge of the first hole. The "diamond" shaped area between the rows of holes is quite "meaty" and looks  like it would remain intact if a hole was drilled between the holes. So at least for those bricks, the best place for ankascrews would be between the holes as long as they embedded about 80mm+, with drilling into the end being a recipe for disaster. Of course your bricks might be completely different. Certainly worth trying to see their structure. 
Never thought much about it before but for anything substantial, fixing into extruded bricks can be quite an issue.

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## phild01

> Never thought much about it before but for anything substantial, fixing into extruded bricks can be quite an issue.

  One deck I did was up to the brickwork and wanted to place a ledger.  The bricks were so full of voids, I ended up getting brick piers to support it - rest easy.

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## David.Elliott

> or.... can you avoid all together and use stump holes and bearer? Joists can cantilever a bit so your stump holes can be situated well.

  This'd be my method...
probably costs a little more, but considering the potential problems drilling those bricks it's a great idea. Just done exactly this but for a different reason. The cottage does not have a square, flat or straight
piece of original timber on it...so freestanding the verandah floor frame, that also allows for visual termite inspection was an easy answer...
I've done ledger boards before by drilling, for items that don't have foot traffic. Not sure I'd trust it for anything else...with those bricks...

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## bobfloyd

Cheers for the help guys.  I guess I'll just drill a few test spots and see what it's like. 
I can't put holes and stumps instead, there are pipes under there and I don't know exactly where. 
I might be able to build piers I suppose. 
This is a very low narrow deck (basically a long timber step, so hopefully the ledger board technique will be adequate. 
Cheers.

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## phild01

How high off ground level is the finished deck height where it is against the bricks?

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## bobfloyd

About 150mm.

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## phild01

150mm isn't very high to be using a ledger.  So 110mm will be deck and joists leaving only 40mm.  If it is this close I would consider bedding some H4 sleepers on the ground for the joists.

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## bobfloyd

Yeah, that's what Im essentially doing for the bearer that is 1m out from the house, putting a treated class 1 bearer in a gravel trench.  I thought attaching a ledger would be an easy way to make a nice solid step. 
We'll see, if I have trouble with the ledger I may well end up sitting it straight on ground. 
Another question, would I have more luck using a shorter fatter ankascrew with the hollow brick.  Probably not I guess. 
Cheers.

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## phild01

Haven't used an ankascrew before.  Have used Dynabolts and feel they are ok if the anchorage is sound.  If this doesn't seem good I would soon resort to chemset.  What you are doing is so close to the ground it becomes a moot point and likely to be a good result anyway.

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## chalkyt

Have you dug down to see if there is a footing pad which extends outside the line of the bricks? You could be lucky and have enough exposed footing to support a brick (even on edge or on end?) so that you can put "mini-piers" comprising only one or two bricks to support your ledger just above the ground? if you were worried about the "mini-pier" tending to tip outwards an ankascrew through into the existing bricks would probably prevent this and be O.K. since it is just holding things in place rather than being load bearing... just a thought as an alternative way of tackling the problem.

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## David.Elliott

Good one chalkyt!

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## GeoffW1

Hi, 
Extruded bricks are a problem for sure. I gave up on using dynabolt type fixings because with our bricks it was too difficult to dodge the holes which made their expansion petals much less effective. The Ankascrew type of fixing has the advantage that it is not an expansion design and does not so much tend to burst the brick internally and become loose. 
I've got into the habit of choosing a length which can go through the brick holes and into the solid stuff on the far side of the brick. It has worked so far. 
Cheers

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## Belair_Boy

> Another question, would I have more luck using a shorter fatter ankascrew with the hollow brick.  Probably not I guess.

  Personally I would be using 12mm diameter Ankascrews and go longer than shorter.  They rely on cutting a thread in the masonry and if there is not enough depth they will rip out the hole before reaching full torque.  Hole diameter is important for success so some experiments will help.  I use ramset ankascrews which use a 6mm hole and power fasteners screw-bolts which use a 6.5mm hole and it does make a difference.

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## bobfloyd

Cheers guys. So far so good with the 10 x 100 Ankascrews.  I drilled the holes in the ledger first, making sure to not hit a vertical mortar line, then drilled with a 6mm, then an 8mm, finally a 10mm.   
Takes me a good 5-6 minutes or so all up to drill each hole.  Feels like ages.  The 6mm obviously takes the longest, the others not too bad.  How long are guys taking to drill holes like this?   
I might just need a helper manning a second drill.   :Redface: ) 
My bricks are 10 hole, I looked at a sample one I had, they are reasonably meaty I guess although I'm only going in 50mm (i.e 50 through the timber/50 through the brick). 
Also, while I think of it, how long can I expect this particular brand of bit to last doing this job?  Should I expect to buy new bits after a dozen holes? 
And another question; on the first hole I was a bit more reckless and wasn't happy with it, so I put a10 x 120 in there, and that locked in nicely.  The only thing is that it is not galvanised, it is the plated ankascrew (can't get 10 x 120 galvanised).  Given it's not going to get wet wear it is, I can't see it rusting out any time soon so should be fine I think? 
Scott.

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## chalkyt

Sounds as thought your ankascrews are biting into the brick O.K. 50mm would be at least 30mm into the front web before any voids in the brick and another 20mm or so if you manage to jag the web between holes. I would try 1) just the 8mm drill and see if the hole is O.K. for the ankascrews, then 2) just the 10mm drill and see if ditto. This saves you two lots of drilling, but heed the warnings about holes being too big... it really is a matter of your judgement. 
Re the drill lasting... if you are using a hammer drill that isn't too fierce, I would expect the bits to last the job. The Kango bit that you mentioned fits into a normal drill chuck. Kango is a well known brand but with most brands quality is all over the place even though they are labelled 'made in Germany', you just never know. Generally the SDS type of bits seem a bit more robust/drill quicker but that may be just that they rattle around in the SDS chuck and are probably more expensive to make and so this reflects in the quality. Bunnings used to sell an Ozito SDS hammer drill for around $70. They are "handyman" units but really are pretty hard to kill (I killed one, but it was because a circlip in the chuck broke). It is usually heat from too much speed and not enough hammer that kills bits.  
Your plated screw should be O.K. since your ledger is isn't CCA treated, this kills plated screws quickly. In any case, your spacing of 450 seems to have plenty of margin of safety since most tables recommend 600 spacing of fixings for 90x45 ledgers, so one failed fixing isn't likely to cause the whole thing to crash down without warning. If you aren't sure, just put another one in alongside it.

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## bobfloyd

Cheers.   
I think my bricks are similar to your ones chalkyt, 2 rows of five holes.  The drilling time will obviously depend on where on the brick I hit, I'm just aiming for anywhere as long as its not too close to the edge.   But does at least 5 minutes per hole sound about right?  I thought the drill would get through quicker than this..?  
When I screw the ankascrew in, I give it a light lithium grease spray first, then turn it till starts to get tight, then back it out a bit, then wind it back in until it is snug against the timber but I don't tighten it much more past firmly snug.  Hopefully they don't crumble out when I hammer the joists etc in.  I can stand on the ledger and it feels very strong.  It is always a little anxious learning something new.  
My ledger is CCA unfortunately.  How long will that zinc plated Ankascrew last?  Will it rust out in a year or are we talking a lot longer?  I could dab the head with bitumen paint, but for the bit inside the timber I dunno.  Why don't Ramset make longer 10mm screws?????  I'm reluctant to unscrew it again as the screwing unscrewing might erode away the brick thread.  Maybe I could try slipping a 12mm x 100 hot dipped ankascrew in there instead, the 10mm hole that eroded a way a bit on my first attempt might take a 12mm.

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## chalkyt

Your first post said you were using Spotted Gum for the ledger (i.e. non CCA treated hardwood). Nothing wrong with changing to CCA Pine (most tables give ledger fixing centres for all timbers at 600) although the issue of corrosion in fixings rears its ugly head. Others might be able to give you more information on corrosion, however my recollection is that this first came to attention about 30 years ago, when plated fixings were found to corrode after five years or so in CCA treated timber. Hence the special "green" or galvanised screws for CCA timber coming on the market. 
5 minutes per hole sounds a bit long. With the right hammer drill and bit, I would expect around one minute, including blowing the dust out. I haven't used ankascrews much, but I am not sure about lubricating them. Others (or Ramset) might be able to tell you more. When I have used them they seem to crunchy/grindy screw their way in if the hole size is right. I don't know how they will stand up to hammering as each blow could cause the cut thread in the bricks to crumble a bit. Once again, others might know more. It would certainly be worthwhile nipping the ankascrews up after the joists are in place.  
Re the dodgy screw, try using a 12mm screw, or as I suggested, just put another 10mm screw in near it.

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## bobfloyd

The timber place told me its spotted gum and that spotted gum is still CCA treated, it has the CCA stickers on the end of the lengths.  ?? 
Btw, where are the ledger tables? 
Yeah, 5 minutes does seem a bit long, can anyone else chime in and confirm what their drill time is?  I'm using the drill bits mentioned, brand new, and an Ozito hammer drill from Bunnings.  Maybe it comes down to the drill Im using? 
I think I'll put the 12mm screw in, thanks for the advice about the corrosion etc.

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## phild01

Five minutes is too long.  Do a smaller pilot hole first to speed this up and avoid using a rotary hammer in brickwork, just a standard hammer drill as you are, as it can blow the back part of the brick out.

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## bobfloyd

> Five minutes is too long.  Do a smaller pilot hole first to speed this up and avoid using a rotary hammer in brickwork, just a standard hammer drill as you are, as it can blow the back part of the brick out.

  I started with a 6mm pilot hole,should I start smaller again?  Too small and the bit might snap though?? 
I wonder what Im doing wrong. 
Pilot hole, brand new bits, regular hammer drill. 
I'm pretty sure the drill is on its fastest speed - is faster drill speed better, or will that heat the bit up too much and dull it? 
Am I not applying enough pressure to the back of the drill?  I've heard to push firmly but not blue in the face firm. 
cheers for the help.

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## phild01

I guess this is something needing observation of your technique.
Don't go smaller than 6mm. 
I'm guessing you are working with hesitancy.
Use firm pressure and adjust speed more fast than slow.  If it is taking 5 minutes then you might be destroying the drill tip with too much friction heat and you will get nowhere.  The drilling needs enough pressure to get the hole done as quickly as possible.  When you withdraw the bit make sure it is not turning blue from excessive heat.
If it is taking a while then intermittently withdraw the bit to avoid overheating.
Also the quality of your drill may be an issue and is something I didn't realise until I got a quality Metabo drill.

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## METRIX

> I started with a 6mm pilot hole,should I start smaller again?  Too small and the bit might snap though?? 
> I wonder what Im doing wrong. 
> Pilot hole, brand new bits, regular hammer drill. 
> I'm pretty sure the drill is on its fastest speed - is faster drill speed better, or will that heat the bit up too much and dull it? 
> Am I not applying enough pressure to the back of the drill?  I've heard to push firmly but not blue in the face firm. 
> cheers for the help.

  Have you got the drill going forwards, sounds like it going backwards ? 
These holes should take about 15 seconds to drill

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## justonething

The problem could dull drill bits. New bits should to sharp but sometimes cheap masonry bits are not sharp. Also the drill could be a problem, cheap crappy hammering action.

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## chalkyt

For good information on timber spans etc, Google... "Timber Queensland, Decks". Their technical Bulletins 4 & 13 are full of good stuff. They give 900 max spacing for 90x45 ledgers, but with 12mm fixings. Also DesignPine has a good downloadable program for their pine timbers (which are dressed sizes) but you can make a judgement as their sizes are quite close to "standard". Other people such as The Log Factory and some of the Hardwood Suppliers also have tables on Google... just search for "timber spans" and heaps of stuff will turn up but I have found that the Timber Qld data is very comprehensive with information about the right way to build things. 
I know that spotted gum isn't regarded as durable for in-ground applications but wasn't aware that it came CCA treated. We learn something new every day on this forum! 
Metrix might be spot-on. I hadn't thought of the drill running backwards. I have an old Ryobi Hammer Drill that I use for small jobs (i.e. wall plugs etc). It is fairly "gentle" and not much good for big holes, and it can easily be accidently put into reverse. It still drills holes this way but is very slow and eventually I realise that it is going backwards. 
Does the Ozito Drill have a SDS chuck or normal key type chuck? Generally (but not always) the SDS bits are good quality whereas straight shank masonery drills can be cheap and nasty and can slip in the chuck if not tightened properly. Having said that, Kango bits should be a reasonable quality product as it is priced about the same as Suttons and others. 
Clearly the "whole world" is watching your job with interest... keep us posted.

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## bobfloyd

Hi guys, cheers for the help. 
The drill is definitely not going backwards, I not that silly.   :Biggrin:  
I'm applying constant firm pressure but Im not putting all I've got into it...should I be? 
i am withdrawing the bit every 30 seconds or so to clear out the flutes, I.e. I keep the drill running, pull it out a bit, push it back in. 
The drill bit has blackened a bit, but I expect that's normal. 
It hasn't got progressively worse, it took a while even with the new bit. 
Remember that the house is 20 years old, so not the solid bricks,but the harder hollow bricks. 
Could it simply be that they are damn hard bricks? 
Or should I hire or borrow a more powerful drill? 
I was certainly expecting to drill through in less than a minute per hole. 
Cheers.

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## phild01

Might be a combination of over-fired bricks and the cheap drill. Does the 6mm travel in ok, if so use several different sized drill bits until it is right ..all I've got.

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## bobfloyd

> Might be a combination of over-fired bricks and the cheap drill. Does the 6mm travel in ok, if so use several different sized drill bits until it is right ..all I've got.

  Yeah,I'm starting to think that myself.  Just really bl**dy hard bricks (which is probably a good thing as far as the house itself goes I guess). 
6mm gets through, but it's a good 2-3 minutes of drilling, and that's even after if "skips" a section as it encounters some part of one of the holes.  Reaming the hole out to 10mm is a touch faster. 
It's incredible to think that this could possibly be done in seconds with the right tool!

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## phild01

> Yeah,I'm starting to think that myself.  Just really bl**dy hard bricks (which is probably a good thing as far as the house itself goes I guess). 
> 6mm gets through, but it's a good 2-3 minutes of drilling, and that's even after if "skips" a section as it encounters some part of one of the holes.  Reaming the hole out to 10mm is a touch faster. 
> It's incredible to think that this could possibly be done in seconds with the right tool!

  If you have quality bits (and I have found cheap ones can sometimes outperform brand name), then it seems your drill could be the bigger problem.  When I drill brick I have an assortment of bits to muck around with and there are significant differences.  I am concerned your bricks might be hard and brittle and could crack with a fixing like this.  I still would avoid any temptation to use an sds type drill.

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## bobfloyd

Yeah a friend of mine has a Hilti jackhammer/drill that he's offered. 
I'm thinking that "slow and steady" might be the better option though? 
If I belt through these holes too fast I might overstress the brick...? 
What I'm going to do is assemble the first stage of the deck legers/joists/bearers, but no decking boards, then walk on it to test it out a bit.  If the Ankascrews are sound, I'll press on.  If they are not I'll change to Chemsets. 
Learning a lot about bricks.   :Smilie:

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## chalkyt

Just did an "experiment"... tried drilling an extruded brick using an "el cheapo" bit in the old Ryobi hammer drill. It took just over a minute with an 8mm bit to drill through the front web into the holes. Then tried a 6mm SDS in the Ozito (couldn't find a 8mm) ... took about 5 seconds before the brick broke, so tried again this time trying to be gentle, with the same result even though I was trying to drill into the web between the holes. Hmmmm! The 8mm hole is the middle one. Listen to Phild01 as the SDS is a lot more aggressive (and the drill is more powerful). My current guess is that you have very hard (and possibly brittle) bricks. 
Just one of those 10 minute jobs that is going to take two days!!!

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## bobfloyd

Ah cheers for that mate - you are a legend!  Thanks for the photo too - nice! 
Yep, I think that's it, these modern bricks are hard as hell.  Perhaps my initial drill is only taking  minute too, but it feels like ages.  I'll time myself on Saturday.   :Smilie:  
Fingers crossed the end result is a good one, even if it does take me longer using the slow and gentle drilling. 
I figure if I alternate between doing some drilling and then a bit of construction, it won't be so bad drilling slowly. 
BTW - is your Ryobi variable speed?  Did you have it cranked to full speed? 
Scott.

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## phild01

> Just did an "experiment"... tried drilling an extruded brick using an "el cheapo" bit in the old Ryobi hammer drill. It took just over a minute with an 8mm bit to drill through the front web into the holes. Then tried a 6mm SDS in the Ozito (couldn't find a 8mm) ... took about 5 seconds before the brick broke, so tried again this time trying to be gentle, with the same result even though I was trying to drill into the web between the holes. Hmmmm! The 8mm hole is the middle one. Listen to Phild01 as the SDS is a lot more aggressive (and the drill is more powerful). My current guess is that you have very hard (and possibly brittle) bricks. 
> Just one of those 10 minute jobs that is going to take two days!!!

  You have the same one that died on me.

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## chalkyt

Yep, the first one died... broke a 50c circlip in the chuck, so Bunnings' solution was to give me a new drill. Duh! 
Hey, Scott. The Ryobi is variable speed  and I was drilling with the hammer and highish speed. Welcome to the world of home renovations... Motto "expect the unexpected!"

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## bobfloyd

It's also about getting huge amounts of mixed advice. 
Googling this topic elsewhere everybody seem to say "you need an SDS drill". 
I'm more inclined to agree with the opinion here, even though I haven't personally tried an SDS drill.  I think the SDS drill will break my bricks. 
Incidentally,I chatted with a Bunnings staff member in the tools department and he also didn't think I was doing anything wrong, he concurred that these are just really hard bricks!  :

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## METRIX

> yes, this is a typical issue.  Have you considered using threaded rod and a chemset.  Would need compressed air to blow holes out and is more expensive.

  No need for compressor, $9.50 will do the trick  Ramset Hole Cleaning Pump I/N 2260405 | Bunnings Warehouse

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## METRIX

> It's also about getting huge amounts of mixed advice. 
> Googling this topic elsewhere everybody seem to say "you need an SDS drill". 
> I'm more inclined to agree with the opinion here, even though I haven't personally tried an SDS drill.  I think the SDS drill will break my bricks. 
> Incidentally,I chatted with a Bunnings staff member in the tools department and he also didn't think I was doing anything wrong, he concurred that these are just really hard bricks!  :

  SDS drill won't do any more damage that a non SDS type, the only difference between a SDS drill and a NON SDS one is the way the chuck holds the bits, the rest of the drill is identical. 
You can buy good and bad quality SDS or NON SDS drills.

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## phild01

> SDS drill won't do any more damage that a non SDS type, the only difference between a SDS drill and a NON SDS one is the way the chuck holds the bits, the rest of the drill is identical. 
> You can buy good and bad quality SDS or NON SDS drills.

  There is a distinct difference between my SDS rotary drills and my Metabo hammer drill.  The SDS makes mince meat of drilling rock and concrete simply because it has a different and more aggressive type of impact.  The Metabo on hammer won't do what the SDS will.  http://www.ecmag.com/products/cool-tools-rotary-hammers

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## METRIX

> There is a distinct difference between my SDS rotary drills and my Metabo hammer drill.  The SDS makes mince meat of drilling rock and concrete simply because it has a different and more aggressive type of impact.  The Metabo on hammer won't do what the SDS will.

  One important work you used there is *"Rotary"*, the SDS refers to the type of chuck not the drill.
Your SDS drill is a Rotary design (which is typical for SDS equipped drills), your Metabo is not a rotary design and probably does not have a SDS chuck, the major difference as to why your SDS rotary drill will eat through concrete and your Metabo Hammer will struggle is the Rotary design of the drill, the SDS part won't make any difference, except it holds the drill bit from slipping, and is much easier to change. 
A typical hammer drill has a standard chuck and uses bits that have straight  shanks (ie no cuts in the drill bit at the end).  
Rotary hammers use bits that have slots and grooves  in the drill bit shank these are called SDS bits, they are used because a typical rotary drill is harder on the drill bits, and will cause them to slip in a normal type of chuck. 
There is a  major difference between a standard hammer drill and a rotary hammer  drill, A standard hammer-drill uses 2 grooved plates that rotate  opposite of each other; when they slip and the grooves connect, a bang  is heard this it the "hammering" of the chuck in and out, this allows a TCT bit to go  through concrete fairly efficiently. 
A *rotary* hammer is more  efficient than a regular hammer drill, it drives a piston that  compresses an air pocket, which in turn, pounds the chuck with  high impact. 
A rotary hammer will out do a regular hammer drill every time, they both will achieve the same result but the rotary hammer will do the the same job in far less time, with  less noise and with less effort.  
For drilling  into tough materials like aged concrete, a rotary hammer is the only  tool to use. 
I also have an older Metabo Hammer drill, this rotates at 3200rpm, and if you drill a lot of concrete at these high speed you will burn the bits out, as opposed to my SDS equipped rotary drill it only rotates at 850rpm, but has much more impact than the Metabo and will drill the same sized hole in the same substrate in a quarter of the time.  *Origins of SDS Plus* 
 The SDS drill system was originally designed by Bosch in 1975.  The  name SDS comes from the German “steck, dreh, sitzt” (insert, twist,  fits).  
Bosch publicise the system on the international market as  Special Direct System, although in German speaking nations it is more  commonly known as “Spannen Durch System” (Clamping System).

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## phild01

> One important work you used there is *"Rotary"*, the SDS refers to the type of chuck not the drill.
> Your SDS drill is a Rotary design (which is typical for SDS equipped drills), your Metabo is not a rotary design and probably does not have a SDS chuck, the major difference as to why your SDS rotary drill will eat through concrete and your Metabo Hammer will struggle is the Rotary design of the drill, the SDS part won't make any difference, except it holds the drill bit from slipping, and is much easier to change. 
> A typical hammer drill has a standard chuck and uses bits that have straight  shanks (ie no cuts in the drill bit at the end).  
> Rotary hammers use bits that have slots and grooves  in the drill bit shank these are called SDS bits, they are used because a typical rotary drill is harder on the drill bits, and will cause them to slip in a normal type of chuck. 
> There is a  major difference between a standard hammer drill and a rotary hammer  drill, A standard hammer-drill uses 2 grooved plates that rotate  opposite of each other; when they slip and the grooves connect, a bang  is heard this it the "hammering" of the chuck in and out, this allows a TCT bit to go  through concrete fairly efficiently. 
> A *rotary* hammer is more  efficient than a regular hammer drill, it drives a piston that  compresses an air pocket, which in turn, pounds the chuck with  high impact. 
> A rotary hammer will out do a regular hammer drill every time, they both will achieve the same result but the rotary hammer will do the the same job in far less time, with  less noise and with less effort.  
> For drilling  into tough materials like aged concrete, a rotary hammer is the only  tool to use. 
> I also have an older Metabo Hammer drill, this rotates at 3200rpm, and if you drill a lot of concrete at these high speed you will burn the bits out, as opposed to my SDS equipped rotary drill it only rotates at 850rpm, but has much more impact than the Metabo and will drill the same sized hole in the same substrate in a quarter of the time.  *Origins of SDS Plus* 
> ...

  Yep, the link I added (maybe just after you saw my posting) says all of that and is what I am trying to say as well.
If it is suggested to someone to use an SDS drill, then as far as I know, they will likely pick up a rotary hammer drill. Because when you look at standard drills when people buy one, it will be a non SDS drill, but if they were to select an SDS drill, it is most likely they are buying a rotary hammer drill.

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## chalkyt

Good summary Metrix. My experience is just what you said. The SDS Ozito is fairly brutal and that is probably why the test brick broke easily, not because of the SDS bit as such. I twigged to the "SDS brutality" when drilling for some wall plugs in a single extruded brick wall some time ago and found that the back of the brick had broken out then I went around to the other side of the wall, hence the old Ryobi for wall plugs in extruded bricks now. 
For those interested, I spent some time as an Industrial Engineer in a brickworks, so FYI, following is roughly the manufacturing process and some clues on how to tell the difference between the brick types. 
As I said earlier, extruded bricks are made from a soft toothpaste consistency water and clay mix. The mix is squeezed through a die, cut to size, then fired. The whole thing is a continuous process a bit like a production line. But, they do tend to be harder and somewhat more brittle than the "old fashioned" dry pressed brick  
Extruded bricks can sometimes be hard to recognise once they are in a wall if you don't know what you are looking for and can't see if they have holes or (or a frog as in dry pressed bricks). In the extruding and cutting process, the die edge and cutting wires (like a cheese cutter) catch on any small solids in the clay and drag them across the surface so you get "scratch" marks all going in the same direction. As well, the wet bricks are sprinkled with decorative "frit" (a mixture of different coloured solids) before firing which the melt or bind to create the decorative surface. This decorative treatment is only on the surface and not throughout the whole brick. 
Dry pressed bricks are made as the name suggests, from dry/damp clay which is just pressed together and fired. They are solid all the way through. Depending on the clay mix, temperature of the firing and reduction time (closing of the kiln to reduce outside oxygen so the O2 from oxides in the clay "burns out" and causes the oxides to change colour), the colour and surface appearance of the bricks change both on the surface and through the brick. 
The reason for this waffle, is to point out that the manufacturers try to make extruded bricks that have the character/appearance of dry pressed bricks (which are more expensive to make as they are done in batches and of course are seen as a premium product which sells for a lot more). So by doing this, the different brick types can be hard to tell apart unless you are aware of the little tell tale signs. Not much of a problem if you are building a house, but a real bugger if you are drilling holes in them!

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## bobfloyd

Excellent summaries and info guys, thanks. 
Chalkyt, so they still make those solid frog bricks?  Why would anybody choose them deliberately over the extruded bricks? 
Perhaps if they are going to be drilling them.   :Smilie:  
Cheers

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## chalkyt

I know we are getting off the track a bit, but the lesson continues... 
I don't know if there is any technical difference in the performance of the bricks (don't think so), but aesthetics play a big part in what bricks people (and architects) choose.
Generally, extruded bricks are cheaper (from around $800 per 1000 for commons and $1200 or so for face bricks). Dry Pressed are mostly used for face bricks and go from $1200 to $2500 per 1000. So on a typical house of 10,000 to 15,000 bricks there can easily be a $10,000 difference in cost. 
Then the aesthetics bit... Extruded bricks generally have adequately square/straight edges and all look much the same for a particular type. This means that for a large building, several batches can be used that will all look alike and so avoid the need for mixing batches by hand (a bit like mixing two cans of tinted paint to make sure that you don't end up with two slightly different colours). Ever seen a large brick building where there seems to be a stripe running around it? Whoops... someone didn't mix batches. 
 From a production point of view, extruded bricks are process driven and don't involve a lot of labour. They can be made from a wide range of clay types since the appearance is determined by the surface cutting and frit used (which can be controlled), so material supply isn't that critical. Having said that, their overall appearance and texture is fine for most applications. 
Dry pressed bricks on the other hand will generally have variations in colour within any particular batch and certainly between batches. They are loaded into the kiln and fired in batches which can lead to differences in batches. In fact it is usual to hand mix several batches which include light and dark bricks to get the overall colour/texture that the customer wants (or the marketing department promotes). They have to be hand loaded and unloaded into the press and hand sorted when finished, so are quite labour intensive (hence expensive). Their appearance is also determined by the particular clay or mix of clays used. Once the quarry runs out, it runs out! The dry press process also allows them to be made in different shapes for architectural features like arches, decorative lintels, etc. i.e. the dies can be made to produce bricks that are bullnose, rounded, tapered, canted (sloped edge) etc. They have quite sharp edges which are sometimes desirable for particular architectural appearances when laid with contrasting mortar (especially in contemporary style buildings). 
Dry pressed can also be made with special surface or edge features such as sandstock (often rumbled to take the edges and corners off), clinker, etc. The reason clinkers are so expensive is that they are "overfired" (a bit of a "black art" rather than a controlled process) so that they tend to stick together in the kiln and have to be broken apart which results in their characteristic lumpy, uneven face.... and low yield, since some just break and so are lost for sale purposes. 
There you go. Just like the old Castrol adverts... bricks ain't bricks.

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