I have a small unfinished basement (1929 house) into which I regularly venture down (HVAC, electrical panel, IT, some food storage). The basement is surrounded by a (dirt) crawlspace and every time I get the chance, I look around for issues and anomalies. However, I am really frustrated by the darkness and grabbing a strong light every time and moving around is annoying. Also, often paths for the light rays are obstructed by duct work and beams.

I got two simple ceramic lamp holders and put on 6000 lumens LED lamps. While the light itself is good, I would need way more of them to reach behind duct work and beams.

From electrical perspective, I know GFCI is a requirement but bare bulbs themselves are allowed. My breaker for basement/crawlspace is GFCI+AFCI.

Now I got the idea to just use string lights. They are up to 24ft and can be extended (nearly) arbitrarily long. I could just add a simple switched receptacle and run the string light across the entire perimeter, just hanging with nails.

Sounds efficient, easy, cheap. Are there any possible issues to consider?

I am not sure about using an LED string or incandescent string. I would be leaning towards the LED version because it's more efficient and I believe more robust (hoping I do not have to venture into the crawl space often to replace bulbs).

Are there any arguments against LED strings?

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    As you've explicitely asked about string lights, I'm not putting this as an answer, but have you considered a head torch left down there? It possibly wouldn't light up the far reaches as well as well placed string lights, but would be much easier to fit! Head torches are the best.
    – eff
    Commented Feb 6 at 11:31
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    I'm 100% in support of the head lamp suggestion. I've spent a huge amount of time in my crawl space in the last 18 months doing plumbing & electrical for some new construction. The light is always with you and always aimed exactly where you need it, it's never shining in your eyes and you never have to take your hands off what you're working on to hold/aim it. I always have my phone as an emergency backup flashlight and a spare set of batteries, just in case. Plus a plug in lamp near the crawl space entrance, just in case.
    – FreeMan
    Commented Feb 6 at 13:52
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    I'd suggest some strings of LEDs for general low lighting, and a nice bright headlamp. My personal favorite is the Lightbar (no affiliation) that throws a lot of light over a broad angle. More focused beams and my progressive lenses don't get along well because the beam and the part of the lens I need to use at a given distance never seem to coincide... Anyway, you may still be able to get outdoor rated white LED strings on sale after Christmas. Just don't set them to twinkle mode.
    – Jon Custer
    Commented Feb 6 at 16:26
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    Yes, look for outdoor-rated strings at minimum. Consider waterproof strings; they're easy to find on e.g. Amazon.
    – Matthew
    Commented Feb 6 at 16:51
  • Let me clarify again that per my post I am NOT primarily looking for a light when I am working in the crawlspace. As I wrote, I want to light so I can easily scan the crawlspace for anomalies when standing outside in the basement. Hence the headlamp is not the right solution.
    – divB
    Commented Feb 8 at 6:24

6 Answers 6



Other than nostalgia - which sometimes has something going for it, but not for functional lighting in a crawlspace - there are really only 4 reasons for incandescent lighting instead of LED lighting:

  • The original Easy Bake Oven, and some similar things that used a light bulb as a heating element
  • Technical issues, typically where a single incandescent bulb in a fixture will prevent LEDs from blinking or having other problems
  • Where you actually want the heat to help keep an area warm and/or dry - which is not terribly efficient but sometimes can make sense.
  • Inside ovens - LEDs don't like that much heat.

The example string lights you linked don't list lumens. But Googling replacement bulbs, I found pretty much what I expected:

  • Incandescent = 11W per bulb, 40 lumens per bulb
  • LED = 1W per bulb, 50 lumens per bulb

In other words, the LED lights will provide about the same amount of light - maybe more - as the incandescent lights while using 1/10 (or less) of the electricity. YMMV, depending on quality of bulb.

Plus the LED bulbs will generally last much longer than equivalent incandescent bulbs, which is a bonus considering the hassle of replacing bulbs in a crawlspace.

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    Some years ago we had a really bad cold snap, record lows, people's pipes bursting. Local hardware stores were all out of heat tape. Still had plenty of trouble lights (bulb on the end of an extension cord with a hook to hang it). Hanging one with a 100W bulb onto the hose bibs and putting a cardboard box over it kept mine from freezing. So using a bulb to heat occasionally really does work...
    – Jon Custer
    Commented Feb 6 at 13:46
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    @FreeMan: True enough… and yet, nowadays LEDs really are leaving all the other currently available lighting technologies in the dust. Yes, there are crappy LED bulbs on the market, but compared to good (or even just mediocre) modern LED bulbs, basically all fluorescent and incandescent lights are crap. Incandescents still have some niche applications (like oven lights, or photography / photometry uses requiring a near-perfect black body spectrum) but outside those there's no reason not to choose LEDs these days. Unless you need a compact electric heater with an integrated light, I guess. Commented Feb 6 at 15:35
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    @IlmariKaronen, OTOH, "less flicker" is quite possible. An incandescent on AC "warbles" at 50/60 Hz (it doesn't turn off instantly, so it doesn't go 'completely off' the way an LED with no smoothing — or worse, using only half-bridge rectification — does). An LED with good smoothing capacitance — which is to say, driven by fairly constant DC — will be as steady as the DC input. That said, an incandescent on DC will be at least as smooth, perhaps more so due to the filament's built-in "lag". But of course household bulbs are almost universally run on AC.
    – Matthew
    Commented Feb 6 at 16:47
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    FYI, 50lm/W is sort of terrible these days. The state of the art is more like 133lm/W, or was last I looked (which was already maybe a couple years ago).
    – Matthew
    Commented Feb 6 at 16:50
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    @IlmariKaronen, that sounds plausible. The incandescent is probably losing a bit of CRI due to the surrounding glass or other factors. Those numbers however are close enough (both to each other and to 100) that I'd take the claim of "better" with a grain of salt; more like "equivalent". Though I suspect the LED might fall behind if the test were more comprehensive. I don't dispute however that really good LEDs exist.
    – Matthew
    Commented Feb 6 at 17:49

LEDs are a perfect solution. Current LED strips are waterproof, flexible and easy to install. You can buy outdoor versions typically used for holiday lighting (the white ones). There's many choices with brightness rivaling any fixture options. Get a nice long strip or multiple, and turn that tunnel into a Star Trek Jefferies Tube.

The headlamp idea may be useful, but also cumbersome. Something you'll need to keep charged, and is one extra step compared to the simplicity of a light switch.


I have found that old Christmas lights work great. A few light bulbs burned out on our Christmas lights. My wife wanted to get rid of them. I hung them up in our crawlspace and it makes a huge difference. Of course, LED lights would be even better. Good luck with your project. crawl space lit with old Christmas lights.


If it were me, I'd run LED tape. It's low profile, generally bright enough for most applications, and relatively plentiful. You can wire them directly into a circuit if need be, or a switched outlet. The advantages of a switched outlet is that it makes the drivers easier to replace if you get a system that has the drivers upstream from the tape.

(Side note: LEDs are far less likely to fail than the drivers that rectify their current. If you can get something where you can replace the drivers as a discrete unit separate from the tape/string, it will make your installation far easier to maintain.)

If the tape doesn't want to stay, you can lay it over some nails with a wide head, something like roofing nails would be perfect, as the cap will be sufficient to hold it. From there, I'd run a row along the side near the bottom of each joist in the area(s) of interest, as well as a second row attached to the actual bottom of the joists, so that you can also see the ground more clearly.

  • My experience differs. I have replace over 40 led units in my house. It is always the leds that fail, not the drivers. And no, they are not cheap imported junk. Commented Feb 11 at 4:50

Use LED STRIP lights not string lights. These are perfect for the stated requirements. Nice even lighting everywhere, but also importantly they are low voltage, and designed to be stapled (or whatever) to anything, indoors. They are a lot safer that your proposed solution or Christmas lights.

I wouldn't string up miles of 120V lamp cable mounted to wood in a crawl space, cable that is not designed for hard-to-reach, somewhat concealed, somewhat indoor spaces, but is designed to be hung outdoors, usually temporarily, and not designed to be permanent. I would worry about the wire or the sockets or the bulbs failing at some point and igniting a fire. I'd also worry about anyone crawling around down there with tools shattering bulbs that are just dangling from the low ceiling. Even if they are plastic LED bulbs there is still some danger.

If you need to string up any 120V circuits for anything, use MC cable and metal junction boxes but keep it to a minimum and use low voltage for your lighting. If that's what you want ... even light everywhere in a tight space ... it's perfect. Given the hard-to-reach aspect of this, I suggest you buy high quality name brand stuff for reliability.


Since you're just scanning the area, you might want to consider installing a few floodlight cameras. They're so cheap now it really wouldn't cost that much. You'd be able to check more often and from a recliner.

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    The "look around for issues/anomalies" is secondary to doing whatever "HVAC, electrical, IT, food storage" the OP needs to do as the primary reason for going down there. Unless there's some home automation hardware I'm not aware of, getting food out of storage or resetting a tripped breaker via camera is going to be... challenging.
    – FreeMan
    Commented Feb 9 at 15:50

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