When you need to redrill a larger hole over a small one you can cut a disk out of plywood to the size of the smaller hole (use at least 2 layers of 18mm of hardwood plywood for thickness, don't use OSB!!), drill a center hole in the plywood disk, insert the disk in the hole in the wall and use it to center your larger sized diamond core bit. You only need it for the first 2 inches of drilling, after which you need to remove both the disk and the centering bit.

Roger, whenever I’m searching for a video guide, it’s always a relief to find one of yours in the listings.. it means I can separate the wheat from the chaff and not waste time viewing someone doing it wrong / without explanation / doing it in America. Keep up the good work!

Never commented before.. Been watching this guy for years and I never stop learning..so easy to watch..cheers Roger..

I really appreciate the time you take doing these videos. Great stuff. Many thanks.

If doing a soil pipe I do a 150mm cut about an inch deep first and then fit a 110mm and cut through the wall. If a need to join or fit a 90 degree turn I can chip out to the 150 mm cut to create the clearance needed and keep the pipe tight to the wall. Cementing up the gap makes for a neat finish.

This guy is so cool! I love these videos.

Really enjoy your videos Roger. Very informative and love your style.

Awesome work, thanks for sharing your knowledge!

Sex, If you can remember what that's like... Hahah

Great video, cheers

I learned more from this 6 min video then from watching 3 other 10-15min videos about diamond core drilling combined.

Great advice, thanks

The full monty for info and usage. Cheers

Thanks Rog, next time I use a core drill I'll remove the centre bit

Best site on the web. Keep it going as I've learnt tons! I'd be interested in your take on the best drills on the market now for large hole core drilling as there are so many. Are dedicated core drills really better or faster? and do you have any tips on cutting holes high up (i.e. for extractor fans) as I always seem to do my back in doing it from my ladder :/ ?

Good tip, thanks

Thankyou - very good advice. Best I have found.

great vid roger, too many blokes don't know about dressing bits

good video!! keep them coming

I see the Hatton Garden robbers used a Hilti diamond core drill to get through the reinforced concrete wall. They left it behind so hopefully the tradesman they stole it from will get it back.

TY I'm going to be renting one of these to bore a 7" hole through brick

Thanks, dude, cool tip!

realy your videos thanks

Go fro m the outside so you dont blow the face of the brick off

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Beautiful video

In and out! Good tip. :)

great video. To use diamond cores do you need a big powerful drill like yours or will a standard 650w drill do the trick?

Great - I have to drill a couple of 6 inch holes in my garage wall for ventilation. Will be looking to rent a proper core drill. Not sure the clutches on standard SDS+ drills are up to the job...

Great to hear someone who knows what their talking about thanks for the advice paul Walsh

Can you put a link to the tools you were using? Drill bit, vacuum, drill, adapters, etc?

Probably an impossible question to answer but what's the chance of breaking out the face of the brickwork if I'm drilling from the inside-out (1500w SDS+ drill, 162mm diamond core, rotary drilling only. Can't drill outside-in because I really don't want to do it up a ladder). I note that Roger drilled a nice neat hole but what's the chance of a relative newbie doing so with much less professional gear???

Do you turn the drill onto hammer when you are using a diamond.. or are you always using just the drill. I think I was told that you only need to just use the hammer for making the pilot hole then when you have done that you just use the drill option. Thanks

wouldn't a bit of 80 grit sand paper work ?

Now try that on some blue staffs class b’s as a diamond driller by trade even with our professional kit it’s no fun

I got caught out like that drilling through an engineering brick. I thought my diamond core bit was wrecked. I never knew until this day that it could be saved.

“ it’s like having sex if you could remember what that’s like.” Actually , it’s been so long I don’t even remember.😂

good tip thanks

Hi mate , What's the best core drill 240v or 110v? N which is model is best ? Thanks

I drill an inch or so inside then I finish drilling outside the house, less dust inside the this way.

Is that the D21570K or D21580K and how reliable is it?

'In and out like having sex, if you can remember what that's like' 😅

Hey Rodger. never used dry diamond cores are the any faster than tct core? I usually core 2inch and 6 inch into 4 inch concrete blocks.. would like to know before I invest in new gear. great videos btw. Enjoy them a lot. and toolstop are no1 for gear. excellent service.

what's the model of the Dewalt?

Great tips there Roger. What I also tend to do is core drill almost all the way through then go through the other side so you don't have too much of a blowout on facing brick.

No, I can’t remember what that’s like, Roger.

Great video, thank you. But what if you have a 240mm thick solid brick wall (Flemish bond) and only a 170mm deep core? Surely when you get to the end of the core you are stuck with a wad of brick that needs to be chiselled out, no?

What happens if it's a cavity wall? I found when I went through the first layer and started on the second it would jam so frequently! to the point where it got stuck completely. Should I re-insert the pilot hole? Is it because the 2 holes are slightly misaligned?

Uh bit uh the old in and out, aye? I seem to remember that, mate.

...if you can remember what that's like....so true

LOL "In and out, rather like you would if you were having sex...If you can remember what that's like"! You are a Funny Man! Also educational. Thx!

Unfortunately, since I had a stroke, I can not remember what it is like.

Can i use SDS plus drill bit on a standard chuck ? I purchased a 30mm Tungsten Carbide Hole Saw bit for making few holes in a cement plastered brick wall as part of a DIY project at home and it is a SDS plus drill bit and what i have is a pretty basic Hitachi hammer drill, so i wanted to know if this drill bit would be compatible with my drill. Also if I can use it, should a hole saw be used on hammer setting ?

노가다 아저씨 말씀 정말 잘 하시네요!

Which size core drill for 110mm soil pipe? 110mm or 117mm or even 127mm?

Any idea where the dust extraction kit comes from? Googling Dewalt gets me nothing.

I have a bit of metal to cut through inside the concrete that I'm drilling. Its just a vent pipe, the metal is only very thin about a millimeter or so. My question is will the diamond core bit get through that? anyone know?

"Like having sex, if ya can remember what that's like!" LOL. "I've been married 16 years. You only get 7 for manslaughter!" (Mike Harding.... or might have been Les Dawson..??) Try coring thru Accrington brick. East Lancashire. The casts for the bricks had the letters "IRON" imprinted on them, but they didn't reverse the lettering. So, when they came outa the kilns, they had "NORI" imprinted. All the same, I have never encountered bricks so impenetrable and hard as these. Top tip re exposing newer diamonds. Those cores aint cheap!

Glad to hear that i wasent told and know its too late but i want to bring awarness of this evil disease

very useful. a few times a year a need to drill a 5 inch hole through engineering/concrete (new build fireplaces). its always a pain and ive often reverted to stitch drilling, which makes me feel like a muppet. im sure my drill is un powered for the job and worry that a 5inch core drill is too big/dangerous. @skill builder how big can you go, before its dangerous. i once got a quote from a firm to wet drill a 9inch core. they wanted £400....

My diamond core is jammed in and I can't get it out. It's in at full depth of core. Any ideas?

What drill are you using?

I need to drill a vertical blind hole in concrete to locate a pole. I have a 90mm x 480mm core drill. I would really like to go down at least 400mm. How do you extricate the concrete core? Any advice would be gratefully received. Thanks, Barry.

What about if i want to cut a new hole (because the current 110mm hole is 2 inches to the left of where it should be) just about 50mm to the side of a current hole. Is it possible to to this with a core drill ? becuase only one side of the core will be cutting into brick.

I've told the Mrs. that I need to remember what sex is like, so I can drill a hole, she told me the bit is undersized..

Diamond dust or grit NOT diamonds ...

Just like sex, lol

Excellent video, quick, (like sex) informative and well explained 👍

Cheers Roger, very informative. Sex? I'd probably be better at drilling core holes.

Omg what's sex got to do with it? Hehehehe your dirty mind Rodger

Bad language toward the end(in and out) rest is good explanation

Hi what make do you recommend