It was a warm day in So. Cal. Today.
As bizarre as this is going to sound....After eating lunch, we noticed that the patio umbrella on our deck was smoldering!
Apparently during the storms of the past couple of weeks one of our window screens blew off and the low-angle winter sun was reflecting off of the low E window coating and onto the umbrella causing it to spontaneously combust.
That's our best guess.....If anyone has another explanation please post.
We hurriedly took it down, put it in the shade and snapped the pics.
Scary stuff, as we live in an extreme fire hazard area and our deck and house are both slathered with linseed oil.
As bizarre as this is going to sound....After eating lunch, we noticed that the patio umbrella on our deck was smoldering!
Apparently during the storms of the past couple of weeks one of our window screens blew off and the low-angle winter sun was reflecting off of the low E window coating and onto the umbrella causing it to spontaneously combust.
That's our best guess.....If anyone has another explanation please post.
We hurriedly took it down, put it in the shade and snapped the pics.
Scary stuff, as we live in an extreme fire hazard area and our deck and house are both slathered with linseed oil.
Attachments
The linseed oil isn't that fresh. We re-stained the deck several months ago and the house hasn't been stained in a few years.
The umbrella was down since the storms, my girlfriend put it up yesterday morning and noticed the smoldering right after lunch. We have pretty much confirmed that it was the sun reflecting off of the window, see pics. The first pic is seconds before we took it down, note the burned spots and the concentrated sun spot. I took the second pic this morning, and you can see the additional burn mark from the above sun spot.
I'm still puzzled why there are burn "spots" and not a track based on the suns position. Our best guess on that is that the sun was shining through tree branches behind the house.
Needless to say, the screen is getting back on the window today.
Attachments
It was a warm day in So. Cal. Today.
As bizarre as this is going to sound....After eating lunch, we noticed that the patio umbrella on our deck was smoldering!
Apparently during the storms of the past couple of weeks one of our window screens blew off and the low-angle winter sun was reflecting off of the low E window coating and onto the umbrella causing it to spontaneously combust.
That's our best guess.....If anyone has another explanation please post.
We hurriedly took it down, put it in the shade and snapped the pics.
Scary stuff, as we live in an extreme fire hazard area and our deck and house are both slathered with linseed oil.
My bet would be the linseed oil !!!!!
I'm going to wager it was nothing more than strong South California sun reflected and effectively focused on that umbrella by a very reflective window on particularly sunny day.
Even here in MA such things are possible on a hot summer day. I've cooked using a solar oven in this Northern environment so I imagine in S. Cal this would not be hard.
The Trolley Museum in Kennebunk, ME. some years ago lost a trolley car to a fire that started due to spare clerestory windows stored in it that concentrated the sun's rays on a hot summer day. That antique trolley car burned to the ground..
Even here in MA such things are possible on a hot summer day. I've cooked using a solar oven in this Northern environment so I imagine in S. Cal this would not be hard.
The Trolley Museum in Kennebunk, ME. some years ago lost a trolley car to a fire that started due to spare clerestory windows stored in it that concentrated the sun's rays on a hot summer day. That antique trolley car burned to the ground..
Our deck is south facing and it gets hotter than a pistol in the summer. It's hot again today and already too hot to walk on the deck in bare feet.
A few years ago when we were into home brewing, I left a 5 gallon glass carboy out on the deck full of water for a few hours. Same thing, burned a crescent shaped mark into one of the deck boards. The glass/water combo focused the light.
BTW Kevin: I'm originally from your neck of the woods....Dedham, MA.
Last edited:
Or the "scared ****less the sun is going to torch my deck" thread..
now if I can just find an asbestos patio umbrella....
While the glass was manufactured flat, once it is installed in a double paned insulating unit, the difference in air pressure created during manufacture causes the thin glass to be bowed inward a bit, creating a concave lens effect. All of my windows are this way and I can see the lensing effect by looking at the reflection. The sun is often focused to a point on the lawn at times
Melted siding is a common problem and often due to reflection from windows.
YouTube - House Damage - Vinyl Siding Melting From Window Reflection
While the glass was manufactured flat, once it is installed in a double paned insulating unit, the difference in air pressure created during manufacture causes the thin glass to be bowed inward a bit, creating a concave lens effect. All of my windows are this way and I can see the lensing effect by looking at the reflection. The sun is often focused to a point on the lawn at times
Melted siding is a common problem and often due to reflection from windows.
YouTube - House Damage - Vinyl Siding Melting From Window Reflection
Interesting. My neighbor in the construction business said the same thing yesterday, that many of these windows are concave. The window in question is true divided light, ie each pane is a separate insulated unit, so there are 9 individual lenses per sash.
Back when I was a kid my mom used to have some antique glass bottles on the kitchen windowsill for decoration and one day the sun was at just the right angle and set the kitchen on fire. Luckily I was on my way home from a friend's house and saw the flames in the window from a half block away before it spread to the rest of the house. The kitchen was a loss and the smoke damage was a pain to repair and the smell lasted for months.
People just don't think those sorts of things can happen. They can and do.
People just don't think those sorts of things can happen. They can and do.
I think it also is more likely to occur with thermopane windows with a low E coating as are commonly used in more temperate climates. As mentioned in a previous post these may not be completely flat when filled with gas - such windows I think would be unlikely in the tropics, at least until comparatively recently when it became obvious that such windows might lessen the load on central AC systems and save some energy.
Well, strangely enough, even after we put the screen back on the window, we had some more straight scorch marks on the umbrella today. This is one sort of long straight line across several panels of the umbrella.....from what I have no idea. At this point I don't think I'm interested in finding out....even in the name of science.
It was hot & sunny again today, hotter than yesterday.
I took it down today and it's staying down.
It was hot & sunny again today, hotter than yesterday.
I took it down today and it's staying down.
Attachments
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.