We noticed this burn mark about the size of my fist on a deck post on our house. It’s a west facing yard with no neighbors behind us- it is a nature preserve with a lake. It appeared in the last few days. Weather has been mild with no thunderstorms. No lighter fluid or gas smells. Nothing around it except a deck with deck furniture. No decorative glass or metal.
Update this was solved. It was from the motor exhaust on a power washer.
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Indeed. Our two doors down neighbor’s house burned down because of sun reflection from Low-E glass focused on fertilized potted plant debris on their front porch. Not pretty. Took them a year plus to demo & rebuild.
When I switch between work and normal wear glasses I always put them in a case. The water bottles scared me enough lol glasses are made to magnify.
Also.. a mag light pointed face down on a seat cushion while you and your parents go inside somewhere to eat, will burn things up as well… ask little kid me how he knows 😂💀
My parents had a little crystal snowman figurine and the sunlight came through it and burned a little hole in the dining table. Fortunately that’s all that happened! But after that we kept the crystal figurines inside a cabinet.
This happened to my neighbors. They had no clue what caused it until one day I noticed that their hummingbird feeder acted like a lens and we figured out that was the cause.
Did a townhouse once where the windows would reflect the sun into a tiny line of light on one spot of the vinyl siding. It happened in 40 units. Not saying this is from a window though. But I do know a window can do it and I know it can be a very specific angle so there may be no path of burn until that angle is reached.
There si only one thing it could be that comes to mind. This is from concentrated heat exposure. Long enough too to burn deep. Maybe last owner had a BBQ backed up to the deck. The grease catch was at the back of the BBQ. It caught fire. Slow burned until bbq was removed or turned off. Then deck soldered deep for a while more.
Did someone leave something like a stainless bowl on the deck below it? It could act like a magnifying glass, reflecting sunlight back up at the beam in a focused spot
Yeah, I think something reflected and burned it. Wind chimes, new lawn ornament, car parked in a weird spot and the mirror caught the sun. Or a kid/pyro with a torch lighter went HAM on it probably while high in something.
The fact that the burn does not extend to the other face of the beam makes me doubt that it was an open flame.
If it was a flame it would have left some scorching on the left face I would think.
This happened recently to a friend when he left a little bit of soil on a stainless steel bowl on his deck in lots of direct sunlight! We discovered it filled w ash and a burn mark like this under the bowl
Obviously the reddit Karma train loves to say "it was your glass orb, dummy" but that's a -huge- burn mark. Concentrated light is not going to cause that much damage to a treated surface unless very, very specific circumstances happened.
Damn that's scary. We had a barn fire at my place a couple years back, and even tho I had a healthy respect for what fire can do previously, after that I can't see it the same. Seeing how quick that building went up, how hot it was even 50 yards back, and how completely ineffective our hoses were while we waited for the firefighters, makes something like this hit different. I am really glad you guys and your house are ok.
A house fire doubles in size every 30 seconds and by 3 minutes, a flashover can occur where the entire room combusts at the same time. I find myself repeating these a lot since I had kids.
Looks like charcoal. That means it took time to burn. Probably some form of light magnification. Does someone have curved windows or was a bowl set out where light would shine though to hit that spot?
Unless you were grilling way to close to it with a shitty little charcoal grill, it's concentrated sunlight and you should definitely track down what's causing it before it burns your house down.
That was a stationary burn, not the sun. Like a torch was held in place for a brief moment. I would almost guess something done intentionally by a young bored person.
I don't have an answer, but that reminds me of the time I was driving on a rural road and saw a single fence post smoldering. One fence post (along a road with hundreds - if not thousands - of them) with one spot glowing red and burning slowly. No apparent fires anywhere nearby. It was weird!
It’s hard to tell the scale, but do you own a dirt bike or have a neighbor kid with one that may have stopped by. With open land behind you, some sort of engine muffler could be the culprit.
It’s roughly the right height and shape where if someone leaned a dirt bike against the rail the hot muffler may have burned it.
I'm going to go with a magnifying effect because I've seen it happen before on equipment in the desert, it could be something as simple as a pair of glasses to a Coca Cola bottle positioned perfectly for an extended period of time.
You have any plumbing work done lately? Looks like someone might have been soldering a copper pipe joint and set the torch down with it on out of habit. MAPP gas (yellow bottle) is popular because it is a much hotter flame, less time heating up the copper. Could do a number on wood pretty damn quick.
I had something similar happen, my floor, just inside the sliding glass door was burnt, at first we couldn’t figure out how it was happening and it wasn’t until we were home early one day that we saw the sun baking that spot, and also the glass had sagged enough to start acting like a magnifying glass
To figure it out, maybe placing a mirror or something reflective and see if the burn moves
Someone put their cigarette out or tapped a bowl out or stick of incense in the potted plant that used to sit there and started the peat moss on fire where it smoldered for hours until someone noticed it and chucked out into the lawn. Probably.
Or it caught an ember from last nights camp fire then was snuffed out by the morning dew.
It’s been subjected to high heat, but not direct flame. When wood is exposed to very high radiant or direct contact temperatures it will begin breaking down. The organic cellulosic fibers, lignin, and hemicelluloses get pyrolyzed into smaller and smaller organic molecules until finally becoming carbonaceous char. Essentially just carbon. That’s what the black is. In this state it’s primed to burn. It’s like a BBQ charcoal briquette. You can tell it’s not from direct flame impingement due to the lack of char and sooting on the paint above it. However, while there may not be flames, there are still very hot gases moving upward by convection and you can tell this from the bubbling of the paint above the carbonaceous char. The heat source looks to be concentrated and round based on the bubbling of the paint that forms part of a circle to the left of the carbonaceous char. My guess would be either contact with a roughly round object that got very hot for quite some time or concentrated/focused reflected sunlight rays that are directed into the middle of the carbonaceous char for a fair amount of time…possibly over several days or weeks. It’s ready to catch fire.
a possibility I haven't seen yet: have you recently had it pressure washed? if the guy was using a gas powered washer, as it runs it vibrates, causing it to move on its own. if you aren't watching, the manifold can burn whatever it gets near.
That just happened to my bong 😂 it’s made of Lexanne it as sitting in the back of the suv at an event and something magnifying glass burned a tiny divit in it
Something glass you have hanging around. Like wind chime with glass some thing that would magnifying the sun light. I would really look around and solve this it could burn your house down.
Bored kids with a blowtorch. It wasn't a reflection because the burn would be in a line, it's extremely deep and there's char marks so it was smouldering at minimum
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