Home Improvement--General/Stud Finder Significance


QUESTION: Good morning Diane,
I'd like to install a banister on my stairway wall and I want to avoid
screwing into anything electrical.  I'm confused about the stud finder.
It's a Studsensor Electronic Wall Stud Finder by Zircon.  When I scan
the wall and it lights up in various areas, does that indicate wood or
an electrical wire behind that spot?  Do I screw into where it lights up
or where it does not light up?  Thank you very much.

ANSWER: Hello, Julia.

I'm so glad you asked this question! If more people would be as careful as you are, they'd avoid problems. Good for you, for taking the time to ask!

Stud finders can be deceiving. When the readout is blank, the tool is reading air. When the readout shows lights, there's something behind the drywall. Sensors are set up to read the mass of wood, but they may also read conduit or wires.

You may already know this, but here's some basic information: Stairway handrails should be no higher than 37" above the tread, and no lower than 30" above the tread. Studs are normally 1-1/2 inches wide, placed 16 center-to-center, or 14-1/2 inches edge-to-edge.

Here's a trick I've used that works: Make a bunch of dots using blue (removable) painter's tape. Start at 33" above the lowest tread and work in straight horizontal lines, putting a piece of the tape every time all the sensor lights come on. Move up or down 3" - 6" and make another pass along the wall, placing the tape pieces every time the sensor lights up. You should easily see where the blue dots line up, showing you where the studs are, so you can then "connect the dots" where you want to place the banister, secured to the studs. Molly screws and bolts should never be used for safety supports such as banisters and grab bars! Another clue is to locate outlets and switches at the bottom and top of the stairwell; this should tell you what the electrician might have done.

Good luck with your project! You get gold stars for being an informed homeowner!


Diane Plesset, CMKBD, C.A.P.S., NCIDQ
D. P. Design


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Thank you.  I'm sorry I'm so dumb on this but I'm afraid I'm still confused.
You said it lights up when there is wood, conduit or wires but where it lights up,
that's where to place the banister screws.  It seems I would possibly be
screwing into wires.  Sorry for the trouble.

Good Morning, Julia.

You're NOT dumb. My answer wasn't specific enough for you; I'm sorry. Your question is so good, I'm thinking about making a video about it!

If you follow the instructions to place multiple "dots" of painter's tape spaced about 6" vertically where the sensor lights up, the dots should line up and tell you where the studs are. 2x4 studs measure 1-1/2" wide by 3-1/2" deep. If there are dots that don't align, that might be a clue there's something else that the stud sensor is picking up, like conduit or wires.

Most handrails, or banisters, have four support brackets -- one at each end, plus two evenly spaced between the end brackets. The blue painter's tape "dots" will help you see exactly where the studs are, so you can install the brackets on the studs. Unless you're using very long screws, you are not likely to hit wires; electricians usually drill a 1/2" hole through the middle of the 3-1/2" deep studs, giving you approximately 1-1/2" (plus the thickness of the drywall) for the screw. You probably won't screw through wires, if the screws you use are a maximum of 1-1/2" long.

Another thing about how wires are currently installed: electricians usually install a metal plate on the edge of the stud to prevent people from screwing into the wires. I don't know how old your home is, whether you can count on the protective plates being on the studs. If you're not sure, you can drill a very narrow pilot hole where you want the support brackets to be that align with the blue painter's tape "dots." To prevent from drilling too deep, use several layers of painter's tape on the drill bit, starting where the bit attaches to the drill and wind the tape down to about 5/8" from the tip of the bit. The tape will not allow you to drill any deeper, unless you press very hard on the drill. You'll know by the feel of resistance whether you're drilling into drywall or hitting a stud, or if you've hit a metal protective plate on the stud.  The holes will be small, and easy to patch if you miss a couple of spots.

Remember to take your time doing this. Most people get into trouble when they try to rush a project. I hope this clarification helps you understand, so your new handrail will go in perfectly, without any problems.

Wishing you the best of luck!

Diane Plesset, CMKBD, C.A.P.S., NCIDQ
D. P. Design  

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Diane Plesset


I will answer questions about anything to do with bathroom remodeling: design considerations, safety, function, materials (cabinets, countertops, plumbing fixtures and fittings, lighting/switching, heating and ventilation, tile, stone, concrete, tub and shower enclosures, flooring, etc.), saving water, trends, ROI, and appearance.


25+ years as a bath-kitchen design specialist, hundreds of completed bathroom projects (all styles, all investment ranges). Author of "THE Survival Guide: Home Remodeling," co-host of a home improvement program on a local radio station for over three years. Currently hosting "Today's Home" on Lifestyle WebRadio every Sunday afternoon (http://www.todays-home.com).

NKBA (National Kitchen and Bath Association), NAHB (National Association of Home Builders), PRO (Portland Remodelers' Organization), IDPC (Interior Design Protection Council).

"THE Survival Guide: Home Remodeling" (my book, published in 2003), Designers' Illustrated Magazine, Gentry Magazine, Kitchen-Bath Business Magazine, Kitchen-Bath Design News Magazine,Interior Coordinator Magazine (Japan); San Jose Mercury News, San Mateo Times, San Francisco Chronicle, Statesman Journal, Portland Tribune, Oregonian.

Multiple degrees: Bathroom Design, Residential Interior Design, Kitchen Design, and Lighting Design. Regularly attend classes and seminars to maintain current knowledge about codes, trends, sustainability, new products, etc.

Awards and Honors
Awards: Henry Adams Designer of the Year, CoTY, Master Design, Best of the Best, Chrysalis, Excellence (best home in its category), and NABE (best how-to book, 2003). "THE Survival Guide: Home Remodeling" received #1 listing in the City of Chicago publication, "Hiring The Pros".

Past/Present Clients
To see photos of completed projects, visit my website: http://www.dp-design.com/portfolio

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