Cable / stud / pipe detector needed

[graduate_owner]

Hi all,
I'm thinking to buy a stud etc detector and am looking for recommendations. I had a look on Amazon because there are usually reviews there, but every one I looked at has loads of negative comments as well as positive ones, even the fairly expensive ones (£60 ish)
I was wondering if the £20 Brennenstuhl detector from Axminster is any good. Does anyone have any experience of this model? Am I wasting my money? I don't want to spend silly money though.

K

 

[MikeG.]

I've got 3 or 4 of the blessed things. None of them work reliably. A variation in the thickness of the plaster is enough to chuck them off course. You'll get endless false positives, and lots of silence when there should be beeps. I wouldn't waste your money. Invest in a bradawl and some Polyfilla.

 

[graduate_owner]

I need to replace my daughter's electric shower and, of course, the model is no longer made. So I am expecting to have to drill through tiles because there's no chance the mounting holes will match up. I really do not want to hit the supply cable or pipe, so I thought a cable detector might save it from happening.

K

 

[MikeG.]

Through tiles? No. No way. You're lucky to get them to work occasionally through paint.

You could set a depth stop on your drill such that it can't penetrate more than the thickness of the tiles + plaster + plasterboard.

 

[Bm101]

I have a cheap one, it'll be wickes or liddle/aldi or similar. One tip that might help at least on my cheapo is to fiddle with the wheel that deals with sensitivity. As Mike G says, you can get lots of false positives or indeed a lot of negative negatives even on a standard stud wall never mind tiling. It's possibly a lot to ask from basic equipment when you think about it in in realistic terms. Maybe best to think of it as a rough guide.
Turn off the electrics and the stopcock and drain the system before you start might be an idea before you start drilling though I'm sure you're aware of this already :wink: it might be worth noting. Do you have a Volt detector pen? Generally quite sensitive, might help.

 

[MikeJhn]

Drill the holes through the tiles only, then pick out behind the tile with a blunt screwdriver for the plugs.

Mike

 

[Homers double]

I have a Bosch gms 120, I’ve had it for several years and thought it was no good at all, as has been said earlier lots of false readings.
Last year i bumped into a Bosch rep at one of the local tool suppliers, I needed to ask him about a laser level I was thinking about getting, I remembered the detector and how poor it was so I asked about that as well, he told me to place the palm of my hand flat on the wall I was scanning.
When I got back to site I tested the palm on the wall thing and hey presto the scanner works perfectly, i tested it out on a known wall and it picked up all the studs and cable runs perfectly, i now have great faith in it.
I’ve never tried it out on tiles though

 

[HappyHacker]

Over the years I have had a few and none have worked 100% but most can generally pick up cables in plaster but may not always get cables in a stud wall if far from the surface. Most would get a copper pipe. For studs I found the mark 1 knuckle to be more reliable but not through tiles. If it is critical I use a cable tracer, like a CAT and geny for underground pipes/cables but cheaper and smaller, where you put a signal into the cable or pipe and pick it up with a scanner. I am told there are radar units that will detect everything including plastic pipes but have never seen one.

Despite the above I would say a decent £20 detector is better than drilling blind, they will get most cables and metal pipes if not to deep. I had not heard the tip on the Bocsh detector but heard heard criticism of them not working well from others although the demos I have seen of them look impressive, perhaps it is worth trying with a normal detector

I was working on a kitchen with a plumber who had been asked by the customer to core drill a hole for the extractor fan that the kitchen fitters would install. He checked with me that there were no cables where he was drilling and then hit both the hot and cold water pipes to the kitchen, buried in the plaster. He then froze and could not remember where the cold water stop **** was even though he had replaced the day before. It was a few days before everything dried out.

 

[MikeK]

I gave up on the inexpensive stud finders because they do not work well on masonry or concrete walls. The walls and slabs of my house are cast in place reinforced concrete, with rebar everywhere. The only detector I found that works consistently for me is the Bosch D-Tect 150. It's a bit pricey, but it identifies the location of all rebar, metal and plastic plumbing, and wiring. I think it is good for up to six inches in concrete.

My friend was installing a towel rack in his bathroom and I recommended giving the drill points a check before he starts making holes in his wall. Two of the drill points he identified were on a horizontal water line about 3 cm below the surface. We traced the water line from the floor to the boiler and he was able to adjust the height of the towel bar and not hit the water line.