How to drill into a secret room you suspect lies in the voids of your pre-war home

Do a proper job:


A decent fiber endoscope is nontrivial hardware and rather pricey; but the proliferation of cheap and tiny camera optics has created a category of what are effectively webcams on atypically long cables. Requires you to have a host device; but it has gotten to the point where it is cheaper to put a decent camera on the end of the probe and run power and a serial bus than it is to bundle enough optical fibers to get decent resolution.

Most of them just show up as UVC devices, so drivers aren’t an issue; but build quality and durability vary. The cheapies generally aren’t classy stainless-steel-armor-clad ones; but they can take light abuse.


Holy carp… here’s what looks like the same model as shown in that video. Looks like $12 - $14 depending on options.

Or, if you really want to get cheap, here’s one with just a regular USB connector for under $5, with free shipping.

I think I just may have to try out one of these. I’ve been trying to work out how to run some cabling through the walls of this place for a while, and something like this would really help.


For the love of God, BoundegaMontresor!


One of my favorite episodes - scared the bejeebers out of me when I was a little kid!

1 Like

That actually works surprisingly well on drywall. Not on plaster like Rob has, though; speaking from sad experience. Do Not Attempt!

I got mine for free. It is worth every penny it cost me! I have had zero success using it for anything, although my buddy Pedro says it works for him for inspecting rifle barrels. Basically mine was designed to look at the inside of a pipe, and has failed totally at inspecting stud cavities and similar voids. It just can’t focus on anything wide or distant, everything’s a blur.

I recommend a cheap cell phone on a whippy stick.

@piratejenny and @ambiguity are right, it’s BASIC. FORTRAN line numbers are in columns 2-5 and statements start in column 7. Oh Jeebus I am old.

The following video is like an episode of my life. Differences are that my teenage ballista used hemp rope soaked in neatsfoot oil, fired tennis balls and we had it set up in the middle of a suburban street. But I don’t actually know what ever happened to the old thing :(.

Very good point! If you use a multi-blade adjustable hole saw like this one…

…(which are very cheap, in both senses of the word) you can make a larger hole in the plaster, and a slightly smaller one in the lath, and it’ll be ridiculously easy to patch since you won’t have to do anything clever to prop up the disk of drywall. Nice!

Exactly. All the professionals I know are using their cell phones instead of endoscopes, bore scopes, periscopes, &etc. In a drywall type situation, they’ll pull out a replaceable-blade pocketknife and cut a hole big enough to stick their arm through with the cell phone, they don’t even go to the truck for tools. In a trickier situation (like 3-coat plaster on lath, for example :slight_smile: ) they’ll use a cheap OTG USB camera with an LED ring. Since nearly all my computer equipment comes from dumpsters, and I don’t own a cell phone, it’s a little different for me (laptop with logitech “eyeball” camera) but basically the idea is cheap, easily replaceable general purpose tool instead of a durable, reliable, limited use specialty tool.

Steel fish tape and a hole saw set. The learning curve is pretty harsh, but the results are well worth it in my opinion.

I think we’re on opposite coasts of the USA, so that would probably not be cheap!

I hadn’t even thought about that <blush> but now I’m flattered. I’d like to thank Rob, the Academy, and of course The Crawling Chaos.


I know, right? Why am I completely unaware of this advance in technology? I ordered one yesterday shortly after it was mentioned in this thread. I need this, even if I’m not sure exactly why? (No, DIY colonoscopies aside, besides, I just had one! :smile: )

1 Like

Wow. You covered everything!

I still think @beschizza needs to hire you to break into his mysterious room (and that damn safe!).

1 Like

Here’s the outside cut on the barn:

The entrance was between the two boards that are removed, but the hive wasn’t revealed until the board to the left of the gas pipe came off. I eventually had to disassemble and remove the gas wall furnace on the other side of the wall and cut into the floor to get the queen out :frowning: and still haven’t reinstalled the furnace yet because the burner needs to be rebuilt and we’re still dealing with other issues.

The bees were amazingly gentle after a couple of puffs of pine needle smoke. A local beekeeper and I pulled the whole hive apart with our bare hands and scooped up the stragglers with a goose feather; the only sting was when Tom accidentally crushed one of the workers.

(That yellow crap is fiberglass insulation that was stuffed in behind the furnace. A bad choice for a barn, since it’s a prime nesting material for rodents. I use stiff foam board instead, preferably the foil backed kind.)


(RatMan eyes all that barn board covetously.)

When I bought this place, I very carefully disassembled the oldest barn/shed on the property to harvest the wood. It’s all gone now, alas.

1 Like


Yes, I’ve successfully used that in several areas already (actually, fiberglass rods instead of fish tape, and I haven’t gone full-on with hole saws, but I get the general idea). But the place has certain… challenges due to the architecture, and having a way to scout out the wall’s interior before making a whole bunch of holes that I might need to figure out repairs for later would be extremely helpful. I’m aware of the limits of my handyman knowledge, and I like to plan around those limits rather than charging full speed ahead…

I’m also aware of mistakes the previous occupants made when doing some of these types of projects (which they then had to correct), so I’m trying to avoid passing my own bad judgement on later. Granted, I’m only working with low voltage and not powerlines, but, still… :wink:

Examining your nose hairs? Looking inside your garbage disposal? Seeing if those pants make you look fat without having to use arrangements of mirrors? :slight_smile:


Quick, someone set up a gofundme!


Oh, I hear you. I ran cat5 through a UU church foyer a few years back and the damn interior of the 20’ high wall was framed like some sort of demented honeycomb, 2x6s at every imaginable angle. I ended up cutting into the drywall at six separate places! Since it was drywall, no big deal, really - it’s so easy to patch. But a camera might have let me know what I was in for up front, which sure would have been nice at the planning stage. For one thing I’d have known to get more paint!

Those sweet little chinese inspection cameras @asdasdetc and @AcerPlatanoides linked may be just the ticket for your situation.

In my own house I just use the fish tape like a feeler. It’s like working a plumbing snake; after a while you get to where you can tell which way it’s bending and how much just by the feel of it. I have walls of all sorts of weird composition, including some made of compressed sugar cane waste (1940ish celotex), and layers of home “improvements” of highly variable quality and sanity. There are Tindalos hounds everywhere.

That is awesome. You could light a fire as the last thing you did before climbing up, and be totally hidden! My own secret room had nothing in it but pipes, wires, ducts and a mouse charnel (with 22 mouse skulls as I recall, the house record). Oh, actually it also had some original molding boards that I did end up using.

It’s original, from 1901, with four worked sides (tongue and groove plus beading on both sides). You can’t have it :slight_smile: ! I cut it the way I did so that it can be put back by nailing to a 2x4 scabbed on to the girt. The cuts are angled down to shed rain but I’m also going to caulk them.

If you have forced air HVAC it’s probably ducts. Bang on the wall with your fist and listen for the booming of galvanized sheet; but keep in mind old houses sometimes just send air between the studs without any metal duct at all.


Well, we had radiators and just added central air a few years ago… it likely is something they did in old houses and nothing special… at least nothing worth having to explain to my wife why there is a hole there now…


When she asks you just look at it and say theres nothing there.


Yea, the programs look a lot like a paper tape to me!

1 Like

He found Narnia and he’s not going to tell us.


My (thankfully rare) experiences with fiberglass have left me with no desire to give it another chance to shove delicate silicate strands of pure itching into my flesh with shocking ease. Is the stuff used in insulation different than the kind found in weathered/damaged fiberglass composites, or is this just another example of vermin being able to shrug off just about anything?


I’m clumsy enough that I wouldn’t want to risk dropping my cellphone into some crevice and having to recover it; but I have some close relative of this thing; and it has indeed survived water, though any alleged ratings are probably a lie; and it packs a reasonably adequate camera and illumination in a ~1cm cylinder on several meters of reasonably durable-ish by polymer coated cable standards tentacle.

It doesn’t even come close to the motorized, armored-conduit, low-light-vision inspection camera the guys who came in to redo our main sewer line when it was attacked by roots rolled out; but it probably cost 1% as much.

I love the elegance of the old, fully passive, fiber-bundle endoscopes: elegantly simple concept, precision optics, all that nice stuff; but those are exactly the features that have just gotten hammered on price/performance by the fact that mechanical complexity is expensive; while silicon complexity is crazy cheap if you are buying in bulk.


Definitely the latter. Fiberglass batt insulation is cheap but it’s horrible to work with, especially if you get a short fiber stuck in the inside of your eyelid, where it will put a slice in your eyeball every time you blink.