This is what I do too, but be warned about “fire proof” - a fire that results in the total loss of your house will create enough heat for enough time that fireproof gun safes and smaller fireproof lockboxes will be destroyed, or even if not, their contents will get hot enough to combust anyway.
A bank safe deposit box offers a different security profile that’s probably more robust against fire because banks burn less often than houses.
It’s probably not practical to really be robust against fire without being buried several feet deep.
https://en.wikipedia.org/wiki/2025_Gelsenkirchen_heist
In December 2025, items worth an estimated €30 million were stolen from a Sparkasse bank in the Gelsenkirchen suburb of Buer, Germany. The thieves used a large drill to break into the bank's underground vault and proceeded to crack over 3,000 safe deposit boxes.
Another solution is to engrave your secret on something that’s stable up to household fire temperatures.
do you store stuff in a bank? could you tell me more about it? my account gives me access to one for free and been meaning to put a yubikey there for a while but never have
Floor safes do better than above-ground safes.
Just went through this. Sample size one:
While the fire resulted in the total loss of the house it was actually the water from the fire department not the heat that did proportionally more damage.
As a mental model you shouldn’t think of it as “what if my house burns down?” so much as “what if nice strangers roll up to my windows and chainsaw through my roof and spray 50,000 gallons of water in here?”
Yes everything in the mechanical room melted but everything in the rest of the house got hot, smoky, soaked and then moldy.
For root of trust materiel like social security cards, cash, passports put in a ziplock bag in a fireproof, waterproof safe. But for other storage I use clear “Ezy Storage” brand stackable 50L tubs labeled with Homebox QR codes. In the US, Target and Home Depot frequently stock them. I am very anti black and yellow tubs.
The majority of work post-fire goes to itemizing your house inventory for insurance. Even cataloging all your bathroom’s soaps by brand name rather than generic can make $100 difference. Multiply that by 500x different things.
From a threat model perspective I look at rooms from a “what would be salvageable in here if I emptied a swimming pool’s worth of water from some fire sprinklers”. Furniture and TVs are easy to replace. Other stuff less so.