Would papers burried underground survive a wildfire?
January 9, 2025 7:58 AM Subscribe
Seeing the coverage of the LA fires and reading about people who are away from their homes (like were away before, not evacuated), I was thinking about their pictures (because I'm old and still think of pictures as physical things) and how they will just be done. And I was thinking "maybe people who live in wildfire areas should have some kind of underground storage for irreplaceable papers." Would that work?
Like I can see all the reasons this would be logistically annoying, but would it even work? I was originally picturing people burying their stuff in the yard before going on vacation, just in case, but of course there are a million other things that could go wrong there (and are more probable than a wildfire hitting your house, specifically, while you're on vacation). But then I thought, hey in wildfire areas maybe houses could have little underground storage areas accessed in the basement. I'm picturing a trapdoor (concrete i guess) in the basement floor that you could lower in a box of papers 4 or 5 feet deep. Yes, I realize even that would be a PITA, and probably nobody would bother, but then just got curious if it would work.
Like I can see all the reasons this would be logistically annoying, but would it even work? I was originally picturing people burying their stuff in the yard before going on vacation, just in case, but of course there are a million other things that could go wrong there (and are more probable than a wildfire hitting your house, specifically, while you're on vacation). But then I thought, hey in wildfire areas maybe houses could have little underground storage areas accessed in the basement. I'm picturing a trapdoor (concrete i guess) in the basement floor that you could lower in a box of papers 4 or 5 feet deep. Yes, I realize even that would be a PITA, and probably nobody would bother, but then just got curious if it would work.
Well, basements don't really exist in California, so that's expensive complication #1.
posted by LionIndex at 8:18 AM on January 9 [7 favorites]
posted by LionIndex at 8:18 AM on January 9 [7 favorites]
Underground stuff survives fires. No need to think as limited as some wildfires. Firebombing via wars, etc. The main problem is that even wildfires (and firebombing cities in war) are relatively rare in the probability that they will hit any specific home, so the risk/value vs the cost of building stuff underground, when it is not required for other reasons, is pretty steep.
posted by The_Vegetables at 8:32 AM on January 9 [1 favorite]
posted by The_Vegetables at 8:32 AM on January 9 [1 favorite]
If the underground storage is inside the house or basement, and the house burns down, now your storage is under a smoldering pile of rubble.
posted by shiny blue object at 8:45 AM on January 9 [1 favorite]
posted by shiny blue object at 8:45 AM on January 9 [1 favorite]
I think we don't have basements because of our more stringent seismic construction standards? I'm not sure about that, but as a lifelong Angeleno, I know exactly one person who has an in-the-ground basement, and it's weird enough that literally everyone who knows about it says, "Wow, you have a basement?"
posted by BlahLaLa at 8:47 AM on January 9 [2 favorites]
posted by BlahLaLa at 8:47 AM on January 9 [2 favorites]
If something is important and you're not on a tight budget, you can build anything you need in this regard. Building an underground compartment which can survive all the usual underground stuff (water table, freeze/thaw, insects, etc.) too, plus a fire, AND be readily accessible both before and after a calamity (particularly one that might turn its surroundings into debris) - well, it sounds like a challenge.
A fireproof safe feels like a good solution, but a lot of people who have suffered losses in wildfires report back that they regret taking a safe for granted. Wildfires can get much hotter than normal house fires. Saw someone post that a wildfire in 2018 that took their home melted all their cast iron pans together.
Given the very specific use case of "documents surviving a wildfire", that implies that you are not space-challenged on the property. A shallow locker away from vegetation and structures (not too far away) locked by simple locks & covered by a material that would function as a thermal shield, hopefully rated for not exceeding 200F for 2 hours... that might work. If security is a concern, or if that's a too-inconvenient arrangement for the documents in question, you can try to do something integrated with the home's foundation (without undermining it!) that can only be accessed from inside, and then you just accept the problem of having to dig it out later. But beware of the possibility that a flood occurs (or a fire that is fought by local officials dumping a flood's worth of water on your home) and that is something the storage solution also needs to be designed to survive, specified as days of the locker being immersed that it can withstand.
I'll also add that I'm assuming you're sticking to *documents* and that we're talking about an interior storage space of 9"x15"x3", and that you won't even let anything not made of paper or a sturdier material in there. No plastic bags unless they too are rated for oven-like temperatures. Jewelry is probably fine. If you are intending to expand this storage to precious keepsakes that are more fragile around heat, it's a whole other ballgame.
posted by brianvan at 9:07 AM on January 9
A fireproof safe feels like a good solution, but a lot of people who have suffered losses in wildfires report back that they regret taking a safe for granted. Wildfires can get much hotter than normal house fires. Saw someone post that a wildfire in 2018 that took their home melted all their cast iron pans together.
Given the very specific use case of "documents surviving a wildfire", that implies that you are not space-challenged on the property. A shallow locker away from vegetation and structures (not too far away) locked by simple locks & covered by a material that would function as a thermal shield, hopefully rated for not exceeding 200F for 2 hours... that might work. If security is a concern, or if that's a too-inconvenient arrangement for the documents in question, you can try to do something integrated with the home's foundation (without undermining it!) that can only be accessed from inside, and then you just accept the problem of having to dig it out later. But beware of the possibility that a flood occurs (or a fire that is fought by local officials dumping a flood's worth of water on your home) and that is something the storage solution also needs to be designed to survive, specified as days of the locker being immersed that it can withstand.
I'll also add that I'm assuming you're sticking to *documents* and that we're talking about an interior storage space of 9"x15"x3", and that you won't even let anything not made of paper or a sturdier material in there. No plastic bags unless they too are rated for oven-like temperatures. Jewelry is probably fine. If you are intending to expand this storage to precious keepsakes that are more fragile around heat, it's a whole other ballgame.
posted by brianvan at 9:07 AM on January 9
According to this study, soil temps even a little ways down don't seem to go up that much, so it would _probably_ work.
posted by advicepig at 9:32 AM on January 9
posted by advicepig at 9:32 AM on January 9
I am confident that at a depth of 4-5 below your basement floor, your papers would be fine in a wildfire. But I think there would be two problems. Firstly, how do you design a practical door that is fire and heat resistant enough? You can use a concrete slab on steel with insulation below, but you'd still have potential failure points at the edges. This might end up being a complex problem to solve well because there can be plenty of combustible material in basements, so potentially lots of heat right at the door. Secondly, how do you prevent these papers from being damaged due to moisture? It isn't that easy to keep a vessel reliably dry that is in the ground and by necessity doesn't have ventilation. You could do something with seals and desiccant, but those need replacing, so would add maintenance headache.
posted by ssg at 10:09 AM on January 9
posted by ssg at 10:09 AM on January 9
Personally I'm glad you asked this question because it's something I was wondering too. I was thinking in much simpler terms - like a small concrete lined pit with a dirt covered top, away from the house so it wouldn't be covered by debris. I have fire proof document containers but I'm not sure I'd trust them to actually work in high temps.
posted by annieb at 2:07 PM on January 9
posted by annieb at 2:07 PM on January 9
I don't know if that would work, but a fireproof document safe seems simpler.
Those are often rated for 90 minutes for 1200 to 2250 degrees, and frequently in these major fires that's not enough. It's certainly better than nothing, but not to be counted on as the sole repository of important stuff.
When I worked at the gold shop, we had someone come in with their melted pile of gold coins out of their fire safe that had been through the Paradise Fire. Still gold, but certainly less value as a hunk of metal than pristine coins. And all the papers were scorched black.
Well, basements don't really exist in California, so that's expensive complication #1.
Everyone in my neighborhood has a basement. If you live in a place where the houses were built before WWII, there are usually basements.
posted by oneirodynia at 11:55 AM on January 10
Response by poster: Thanks everyone...in case it was unclear, I'm not in a fire zone and I don't have a basement either, so this was just a hypothetical thing I was wondering, not something I'm actually thinking of implementing. I knew about firesafes, but they're mostly so small they wouldn't even hold one album (and yes, I realize now that an album would have plastic that would melt, in addition to all the difficulties in designing the storage space.
posted by If only I had a penguin... at 8:41 AM on January 12
posted by If only I had a penguin... at 8:41 AM on January 12
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posted by caek at 8:18 AM on January 9 [12 favorites]