Chasing concrete floor
Discussion
As part of our kitchen remodel, the wife wants me to build an island. The actual island is all fine but I want to run power for a few sockets to it and so will need to chase them into the concrete floor. The chase will run about 2.5m from the wall to the island. Importantly (and the primary reason I am asking this question) the house will be inhabited when I'm doing it.
So:
1. What is the easiest/safest way to chase a channel into concrete AND the way that will minimise dust? I have most tools (grinders, SDS drills etc) but I'm guessing that cutting slots with a grinder will create a phenomenal amount of dust. Are the chasers you can hire any better?
2) Are there are issues (aside from buried pipework) that I need to be aware of? Will it cause my house to disappear into a bottomless sinkhole?
3) What is the best type of conduit to use? It'll just be a few sockets so likely 2.5mm T&E running through the channel. What protection do the cables need (I couldn't find any clear guidance on that).
Thanks in advance
So:
1. What is the easiest/safest way to chase a channel into concrete AND the way that will minimise dust? I have most tools (grinders, SDS drills etc) but I'm guessing that cutting slots with a grinder will create a phenomenal amount of dust. Are the chasers you can hire any better?
2) Are there are issues (aside from buried pipework) that I need to be aware of? Will it cause my house to disappear into a bottomless sinkhole?
3) What is the best type of conduit to use? It'll just be a few sockets so likely 2.5mm T&E running through the channel. What protection do the cables need (I couldn't find any clear guidance on that).
Thanks in advance
You'll want to seal all doors to the room, use a chasing tool (like a double disc'ed circular saw, if you're near S London welcome to borrow mine) to cut the channels, a demo chisel or SDS drill to break out the middle and run in conduit. You'll be screeding for levels before most flooring in any event.
ETA - my chasing tool was <£30 from Screwfix/amazon and think it has an attachment for a vacuum hose (although that'd likely only be 50% of the dust created)
ETA - my chasing tool was <£30 from Screwfix/amazon and think it has an attachment for a vacuum hose (although that'd likely only be 50% of the dust created)
Edited by kiethton on Wednesday 7th January 21:50
If you can find one for hire, the triple disc Metabo with dust extraction rig really makes light work of most chases and is probably as dust free as you can get: instead of just cutting the edge of the channel to SDS out later, the middle of the three discs pulls the material out and straight into the vac.
LennyM1984 said:
3) What is the best type of conduit to use? It'll just be a few sockets so likely 2.5mm T&E running through the channel. What protection do the cables need (I couldn't find any clear guidance on that).
I'm sure someone can track down an accessible copy of the regs but I think it was >50mm depth or extra mechanical protection like proper earthed steel conduit/30mA RCD? Basic idea being to avoid anyone accidentally putting something through it. Also realistically you want a conduit big enough to pull the cables through and that won't collapse if something puts pressure on the floor in the wrong spot.
Of course this also assumes the floor construction will let you put a great big deep notch in it.
kiethton said:
You'll want to seal all doors to the room, use a chasing tool (like a double disc'ed circular saw, if you're near S London welcome to borrow mine) to cut the channels, a demo chisel or SDS drill to break out the middle and run in conduit. You'll be screeding for levels before most flooring in any event.
ETA - my chasing tool was <£30 from Screwfix/amazon and think it has an attachment for a vacuum hose (although that'd likely only be 50% of the dust created)
Those double disked saws are great I'd not seen them before and electrician turned up with one and chased brickwork with it done in minutes.ETA - my chasing tool was <£30 from Screwfix/amazon and think it has an attachment for a vacuum hose (although that'd likely only be 50% of the dust created)
Edited by kiethton on Wednesday 7th January 21:50
JoshSm said:
Of course this also assumes the floor construction will let you put a great big deep notch in it.
How would I find this out? The central heating pipes are buried in the floor and one of the runs has been modified/re-routed in the past, so I was assuming that it would be okay... LennyM1984 said:
As part of our kitchen remodel, the wife wants me to build an island. The actual island is all fine but I want to run power for a few sockets to it and so will need to chase them into the concrete floor. The chase will run about 2.5m from the wall to the island. Importantly (and the primary reason I am asking this question) the house will be inhabited when I'm doing it.
So:
1. What is the easiest/safest way to chase a channel into concrete AND the way that will minimise dust? I have most tools (grinders, SDS drills etc) but I'm guessing that cutting slots with a grinder will create a phenomenal amount of dust. Are the chasers you can hire any better?
2) Are there are issues (aside from buried pipework) that I need to be aware of? Will it cause my house to disappear into a bottomless sinkhole?
3) What is the best type of conduit to use? It'll just be a few sockets so likely 2.5mm T&E running through the channel. What protection do the cables need (I couldn't find any clear guidance on that).
Thanks in advance
I had to do similar a while back and opted for an incredibly budget solution that actually worked brilliantly. Bought a cheap, clear plastic storage box, drilled a hole in the side for a snug vacuum hose fit and then cut the channel with the box over the top of the tool and my arms. The amount of dust that escaped was minimal. I'm sure there are more elegant and appropriate solutions but this bodge worked very well. So:
1. What is the easiest/safest way to chase a channel into concrete AND the way that will minimise dust? I have most tools (grinders, SDS drills etc) but I'm guessing that cutting slots with a grinder will create a phenomenal amount of dust. Are the chasers you can hire any better?
2) Are there are issues (aside from buried pipework) that I need to be aware of? Will it cause my house to disappear into a bottomless sinkhole?
3) What is the best type of conduit to use? It'll just be a few sockets so likely 2.5mm T&E running through the channel. What protection do the cables need (I couldn't find any clear guidance on that).
Thanks in advance
megaphone said:
Talk her out of an island, they are a pita, always in the way, stuck in the middle of the room, you have to walk around all the time.
Annoyingly it is quite a large room and so without an island looks rather naked. We could perhaps get a medieval style banquet table and I could pretend I was Henry VIII...Edited by megaphone on Thursday 8th January 08:50
DonkeyApple said:
I had to do similar a while back and opted for an incredibly budget solution that actually worked brilliantly. Bought a cheap, clear plastic storage box, drilled a hole in the side for a snug vacuum hose fit and then cut the channel with the box over the top of the tool and my arms. The amount of dust that escaped was minimal. I'm sure there are more elegant and appropriate solutions but this bodge worked very well.
Nice! That's the kind of budget bodgery I like. Did you use a chasing tool under the box or just a basic angle grinder?LennyM1984 said:
DonkeyApple said:
I had to do similar a while back and opted for an incredibly budget solution that actually worked brilliantly. Bought a cheap, clear plastic storage box, drilled a hole in the side for a snug vacuum hose fit and then cut the channel with the box over the top of the tool and my arms. The amount of dust that escaped was minimal. I'm sure there are more elegant and appropriate solutions but this bodge worked very well.
Nice! That's the kind of budget bodgery I like. Did you use a chasing tool under the box or just a basic angle grinder?If doing it again I'd probably rent a proper chasing tool with extraction but would still put the box over the top.
LennyM1984 said:
The central heating pipes are buried in the floor and one of the runs has been modified/re-routed in the past, so I was assuming that it would be okay...
We talking UFH or just Radiator Feed pipes - not sure I'd be cutting channels in the floor if UFH unless I knew exactly how deep the pipes were - if it's just Radiator feed pipes in the floor then with the heating on a thermal camera should show you where they are unless they are heavily insulated??B'stard Child said:
We talking UFH or just Radiator Feed pipes - not sure I'd be cutting channels in the floor if UFH unless I knew exactly how deep the pipes were - if it's just Radiator feed pipes in the floor then with the heating on a thermal camera should show you where they are unless they are heavily insulated??
Just radiator feed pipes. The kitchen is at the far end of the house so I actually know where the original central heating feed ended and I can also see where they have covered the channel dug when they re-routed it to move the radiator in the opposite direction. There shouldn't be any pipes (gas, water, waste) in the area I need to cut so it is more just about making the cut whilst minimising mess. I think I might just hire a chaser and use the box method for extra dust extractionGassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff