How To See Inside Your Walls
Have you ever wished you had x-ray vision so you could see inside your walls? Are you just curious or are you tracking down a problem behind your drywall like a plumbing or roof leak? Is there a squirrel’s nest in your wall? Are you running a cable in the wall and need to make sure the path is clear? Do you need to see what structure is hidden inside your wall for a building project? If the answer is yes to any of these questions, read on!
These x-ray glasses might not be "real" but there are several practical options for you to unlock the mysteries of what might be hiding inside your walls.
Endoscopes
Originally developed for the medical industry, endoscopes have been used to peer into body canals and cavities as far back as the early 19th century. While current medical grade endoscopes may not be practical for DIY'ers, a wide variety of low-cost endoscopes are now available.
So what is an endoscope? Although they may take on different forms and use various technologies, an endoscope has a viewing probe at the end of a cable with a means of viewing the image collected by the probe. The probe is usually lighted for better viewing and the cable may be flexible or semi-rigid. The image can be produced optically or electronically with a camera.
How do you use and endoscope? To use an endoscope, you'll need access to the area you want to view. If the space is open but too small for you to get in there, like at the roof edge in the attic, you can just extend the scope cable and start viewing. Move the probe end of the cable around and start "exploring". If you want to peer into a wall cavity, you'll have to find a way in which might involve drilling an access hole. But if you want to check out your forced-air ducts or drain pipes, you can just drop the scope in a take a look.
Endoscope feature Choices
Screen or No Screen? There are two main types of endoscopes - Ones that include the viewing screen and others that rely on your phone or laptop's screen to view the endoscope's image. Which one is right for you? You might like the convenience of the models with a viewing screen. You turn them on and start probing. The downside of these devices, especially on the lower cost models, is the resolution and clarity of the screen image. Another downside is the inability to capture images or record videos on some models. Finally, the price of the scope is heavily influenced by the manufacture's cost of including the display. If you're willing to use your smartphone or laptop, a better and more cost effective choice might be an endoscope without an included display. Some smartphone based models are wireless to boot which gives you some extra flexibility when using the scope as well.
Endoscope Features To Consider
- Focal Range Look for an endoscope with a large focal range. This will allow you to view close-up or back up to get the big picture.
- Flexible or Semi-Rigid Cable Most scopes currently on the market have a semi-rigid cable which is great because they hold their shape when needed but can be formed as well. Watch-out for some models that use a flexible cable. Unless you have a specific need for a fully flexible cable, these are not recommended.
- Cable Length Make sure length of the scope cable will work for your intended uses. Cable lengths up to 50 feet or more are available.
- Waterproof Thinking of dropping the scope down the drain to take look? Make sure to opt for a waterproof model.
- Image Capture & Video Recording If you want a permanent record of your scope explorations, consider buying a model that has image capture capability. Scopes that use your smartphone or laptop to display the image are more likely to have this feature. Some stand-alone scopes that have their own screen may have a memory card option to capture still images or videos.
Wall Radar
Wall radar devices are the closest thing to having x-ray vision to see into your walls. Radar technology has been around since the late 1800's when German scientist Heinrich Hertz showed through experiments that electromagnetic waves could pass through some materials and reflect back from others. Of course radar systems are now commonly used to detect aircraft and monitor weather systems. This same technology is now available for DIY'ers at a low cost. A company called Walabot offers a device that attaches to your (Android only) smartphone allowing you to get a virtual glimpse of what's inside your walls.
Thermal Imaging Cameras
Stud Finders
Sometimes you just need to find a stud to drive a nail or screw into your wall. Developed in the early 1900's, the first stud finders used magnets to find the metal fasteners in the studs. With these devices, you're technically not finding the stud but the nail or screw that's in the stud. In the 1970's, the electronic stud finder which works by detecting the density of the wall was developed. Today's electronic stud finders work well and some have the ability not only to find wood or metal studs but can also find live AC wires in your wall.
Low-Tech or No-Tech
Inspection Mirror
Sometimes the simplest tools can be the best. If you need see into a tight spot or even inside your wall, you may be able to use an inspection mirror. Of course if you're looking inside your wall, you'll need access so you may need to cut an opening if one does not exist.
Cellphone Camera
Sounding
Before wall radar and stud finders were around, carpenters used their fist and a little builder's intuition to find out what's behind the wall. The technique definitely falls into the "No-Tech" category. How does it work? You pound your hand on the wall listening and "feeling" for any changes as you make your way left or right down the wall. If you come across a stud, the wall will feel more solid and you'll hear a difference in the pounding. Does it work? Yes. Is it foolproof? No. But in a pinch, a little pounding on the wall might go a long way to find out what might be hiding behind your wall.