ToughButterCup Posted September 9, 2019 Share Posted September 9, 2019 Remember those joists I put in? Well they've come back to bite me again. Trousers on this time. Because a quirk of fate often known as lack of experience , instead of putting in a duct through a wall ready for the MVHR ducting, I have to drill a series of large holes (160 square) through a concrete wall - easy you'd think. Why the fuss? Well, while putting up the POSIs I could have foreseen the need to drill through the wall, but - yes reader, you are there before me. Because I had my nickers in a twist about getting the first floor in, I just had to get the damn POSIs in. Just had to. So, I put the bloody things in - the first 50mm from the wall (so proud of myself for getting that bit right) and carried on, pleased as punch that I was doing it on my own - reasonably successfully. 400 centres. Comes the time to drill the holes. Got the hammer drill (a trusty Teuton Special), got the long SDS+ drill bits. Shoo shoo ! Can't get the drill and the bit between the friggin joists can I? 400 mm centers nowhere near wide enough. Poke it through the gaps - Naah - only let's me drill 10mm. Bugger. I know, pop round the other side and stitch drill from there. Whoo hoo, all's well - except the damn drill keeps binding half way through. The drill kicks and binds - often. Because of where I have to jam myself to make the hole, the kicking drill hits my top lip, thumps my thumb - I've only got 8 of the damn things left for Gods sake. Humour was in short supply. I'd only gone and forgotten how much bloody rebar I'd put in the friggin wall. Enough to ballast Boaty Mc Boat-Face. The drill was binding on the rebar. Warra pillock! Out comes the other Teuton. The Zigger zagger (chop saw). Buggers the blade up in short order. Out comes the third bit of kit all the way from The Fatherland (well, ermmm China) . New Diamond blade, new battery, that'll get the bastard. The rebar is deep in the wall, to reach it, have to hold the angle grinder by the base. Sparks, noise, masses of dust - me suited and visored like Darthvader, can't see a thing. The grinder jams and jerks . Pinches my hand in the hole. Hard. The dust clears to find me hands jammed between my legs in pain, swearing like a trooper and sweating like the sinner that I am. Anyone know how to tell if there's rebar in the concrete you're about to drill? Please? Pretty please? Link to comment Share on other sites More sharing options...
Onoff Posted September 9, 2019 Share Posted September 9, 2019 5 minutes ago, AnonymousBosch said: Anyone know how to tell if there's rebar in the concrete you're about to drill? A cover meter is what you want. Saying that the last time I used one was circa 1987/88. Had to use to detect RSJs beneath a concrete roof slab where there was no drawings or access from below. Link to comment Share on other sites More sharing options...
Ferdinand Posted September 9, 2019 Share Posted September 9, 2019 20 minutes ago, AnonymousBosch said: Anyone know how to tell if there's rebar in the concrete you're about to drill? Please? Pretty please? One for those strong magnets? Link to comment Share on other sites More sharing options...
Onoff Posted September 9, 2019 Share Posted September 9, 2019 Just now, Ferdinand said: One for those strong magnets? Neodymium. Link to comment Share on other sites More sharing options...
Construction Channel Posted September 9, 2019 Share Posted September 9, 2019 I don't trust it personally but I have seen these advertised a lot recently. https://store.walabot.com/uk/walabot-diy-pack.html?gclid=CjwKCAjw8NfrBRA7EiwAfiVJpe2tP-2SEbkl9nlLGhyHUj265gPkWNV3yb4W1_ZWB1doF5FbXh-WOhoCdIMQAvD_BwE Link to comment Share on other sites More sharing options...
Construction Channel Posted September 9, 2019 Share Posted September 9, 2019 With the straightest face I can muster. The best tool to find them is probably the drill... Link to comment Share on other sites More sharing options...
Russell griffiths Posted September 9, 2019 Share Posted September 9, 2019 Go and get one of the new style sds drill bits that go through re bar. On another note if you hit re bar can you not just move the hole 150 mm away, surely you haven’t got any closer than 400 centres. Link to comment Share on other sites More sharing options...
ToughButterCup Posted September 9, 2019 Author Share Posted September 9, 2019 39 minutes ago, Construction Channel said: With the straightest face I can muster. The best tool to find them is probably the drill... Shut yer face Graves. ? Sounds like you've done it more than once..... Link to comment Share on other sites More sharing options...
ToughButterCup Posted September 9, 2019 Author Share Posted September 9, 2019 38 minutes ago, Russell griffiths said: Go and get one of the new style sds drill bits that go through re bar. [...] Ermmm, had a look - nuffin. Link to comment Share on other sites More sharing options...
Onoff Posted September 9, 2019 Share Posted September 9, 2019 (edited) 12 minutes ago, AnonymousBosch said: Ermmm, had a look - nuffin. I think I have a Hilti rebar bit here somewhere but this found at random: https://www.tooled-up.com/bosch-sds-plus-steel-rebar-cutter-drill-bit/prod/174703/?varId=174703&Referrer=affwin&source=affwin We used to drill holes hoping not to hit rebar and if we did change to one of these. I've even used a Starrett holesaw with an extension but it's brutal on them. In theory it's a big no no drilling rebar like we used to and effing up the SE's carefully designed structure! ? Edited September 9, 2019 by Onoff Link to comment Share on other sites More sharing options...
Construction Channel Posted September 9, 2019 Share Posted September 9, 2019 43 minutes ago, AnonymousBosch said: Shut yer face Graves. ? Sounds like you've done it more than once..... Never worked on icf but I have had to get around rebar before. Milwaukee make an sds that supposedly goes through rebar. Only difference I can see is it has 4 cutters on the top but they still bind a lot until they get through it. If it were me and I had already suffered all your defeats I would resign to stitch drilling as deep as I can. Break out what you can with a cold chisel / sds +chisel if you can get it in. Then try to work around the rebar(s) and past them. Then finally cut the bars with a reciprocating saw once you can get the blade past them. 1 Link to comment Share on other sites More sharing options...
Ferdinand Posted September 9, 2019 Share Posted September 9, 2019 (edited) Are there hole saws of an appreciate size that attach to your digger? Bit of a stretch but you never know.... Edited September 9, 2019 by Ferdinand 1 Link to comment Share on other sites More sharing options...
Temp Posted September 10, 2019 Share Posted September 10, 2019 Can you get a right angled SDS drive? And would that fit between the joists? Link to comment Share on other sites More sharing options...
Onoff Posted September 10, 2019 Share Posted September 10, 2019 TEYX is the modern Hilti bit that eats concrete with rebar in. SDS Plus form. Could you maybe core drill round holes then square off afterwards by filling around the duct? How square has it got to be, would 4 smaller, overlapping core drilled, round holes do the job? Link to comment Share on other sites More sharing options...
Russell griffiths Posted September 10, 2019 Share Posted September 10, 2019 Can you not just move the hole ?? Link to comment Share on other sites More sharing options...
ToughButterCup Posted September 10, 2019 Author Share Posted September 10, 2019 39 minutes ago, Russell griffiths said: Can you not just move the hole ?? Yes. But, by the time I'd hit the bloody rebar I was so committed, so annoyed (with my own lack of forethought), soooo over-focused. And to think I used to give lectures to hundreds of students on the role that emotion plays in the learning process. ? Link to comment Share on other sites More sharing options...
Onoff Posted September 10, 2019 Share Posted September 10, 2019 (edited) How far in is the rebar? Maybe sacrifice a holesaw the same size as the SDS bit. Edited September 10, 2019 by Onoff Link to comment Share on other sites More sharing options...
Russell griffiths Posted September 10, 2019 Share Posted September 10, 2019 I would just bight the bullet and buy one of those Bosch drill bits. Link to comment Share on other sites More sharing options...
Onoff Posted September 10, 2019 Share Posted September 10, 2019 50 minutes ago, Russell griffiths said: I would just bight the bullet and buy one of those Bosch drill bits. +1 it's got his name written all over it. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted September 10, 2019 Share Posted September 10, 2019 Or hire a big diamond core drill. That won't care what it's cutting through, I suspect. Link to comment Share on other sites More sharing options...
Oz07 Posted September 10, 2019 Share Posted September 10, 2019 I thought a diamond core is being used. Why isn't it? Link to comment Share on other sites More sharing options...
ToughButterCup Posted September 12, 2019 Author Share Posted September 12, 2019 I found that stitch drilling is faster. A mate called round yesterday. His name might as well be Russell Griffiths. "You got a stud finder?" Yes "Used it?" ? Reaches into my tool bag and roots around. Brings out the Teuton Stud / Bar / Wire finder. Scrapes around on the wall. Waits til it goes green. Marks the spot. You know what happens next. Sometimes I can't see the wood for the trees. 6 more holes to go. ? Link to comment Share on other sites More sharing options...
Russell griffiths Posted September 12, 2019 Share Posted September 12, 2019 2 hours ago, AnonymousBosch said: I found that stitch drilling is faster. A mate called round yesterday. His name might as well be Russell Griffiths. "You got a stud finder?" Yes "Used it?" ? Reaches into my tool bag and roots around. Brings out the Teuton Stud / Bar / Wire finder. Scrapes around on the wall. Waits til it goes green. Marks the spot. You know what happens next. Sometimes I can't see the wood for the trees. 6 more holes to go. ? I bet he’s a good looking bloke as well. 1 Link to comment Share on other sites More sharing options...
Onoff Posted September 12, 2019 Share Posted September 12, 2019 1 minute ago, Russell griffiths said: I bet he’s a good looking bloke as well. Modest too I've heard. Link to comment Share on other sites More sharing options...
ToughButterCup Posted September 12, 2019 Author Share Posted September 12, 2019 3 hours ago, Russell griffiths said: I bet he’s a good looking bloke as well. He's got a wooden leg, a seriously broken nose, every tooth in his head is false and suffers from the worst dose of haletosis I've ever seen. His wig is usually on back to front and he dresses like Greg or Terry on the Simpsons. Apart from that he's a good bloke. 1 Link to comment Share on other sites More sharing options...
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