Stove Ashes

Im sure I’m not the only one who’s always trying to reuse and repurpose things, make the most out of everything and “kill two birds with one stone”…

We recently started using a wood stove and also recently adopted a barn cat. The cat lives in our unheated shed in the back yard. The shes has a small cat sized door cut into it and a 2 cubic foot insulated cat house stuffed with hay inside the shed. The cat house is elevated a couple feet off the floor. Ive been told barn cats dont need heat, even in extreme cold, so long as they can get out of the weather. But I still feel for him out there!

As I was scooping out the wood stove I was thinking about this bucket of hot ashes radiating heat and what to do with them. Dump in the snow, dump in the fire pit outside, dump in the compost all came to mind. But then our cat came to mind…

Here’s my idea: stick the hot ash bucket under the cat house so it radiates heat upwards for him while hes inside. I could set it on sheet metal so the wooden shed floor wont burn. And I could cover it in a wire cage so he cant get into it or tip it over (already have the perfect cage for that). And if something went horribly wrong and the shed started on fire, hopefully he would just leave freely. My only worries is that the ashes would slowly fill the shed with carbon monoxide and kill him while he sleeps.

Is that reasonable to be worried about? Theres no visible smoke coming off the bucket, just heat radiating. And the shed is leaky and not insulated I’d like to think the carbon monoxide would leave or pile up at the peak far above his head.

What are your thoughts? I know ashes and coals are super dangerous but I feel like I’ve thought this through pretty well. Just looking for some opinions!

Hi Brody;
Nice that you are concerned about your new cat.
I'm afraid your ashes will be stone cold in short order. I would not bother.
I know you just acquired this kitty but maybe if there is room in his kitty house a second kitty might be a buddy/house warmer for your current cat!

I think if you're comfortable with the precautions you mentioned, it couldn't hurt to try. I'm guessing there isn't much mass in a batch of ashes though. Maybe you could include heated bricks or a kettle of heated water with the trip you make?

thomas rubino wrote:Hi Brody;
Nice that you are concerned about your new cat.
I'm afraid your ashes will be stone cold in short order. I would not bother.
I know you just acquired this kitty but maybe if there is room in his kitty house a second kitty might be a buddy/house warmer for your current cat!

He had a brother when we got them but they got sick and his brother had to get euthanized, so he’s alone now. And the ashes stay hot for a while. I set some in the garage one morning and that evening they were still hot. Granted it wasn’t as cold outside as it is now.

Michael Helmersson wrote:I think if you're comfortable with the precautions you mentioned, it couldn't hurt to try. I'm guessing there isn't much mass in a batch of ashes though. Maybe you could include heated bricks or a kettle of heated water with the trip you make?

You’re right there isnt much mass. But that bucket of ashes is seriously impressive with how long it stays hot. I think the ashes themselves act as insulation.

I don't think I would do that. On top of the possible dangers, you would have to do it on a regular basis which sounds like a bit of a pain. What I have always done for my outdoor cats and dogs is just to make sure they have a cozy, dry place out of the wind. What I think is extremely important for the coziness is a soft insulating bed.  Old wool sweaters, old pillows with synthetic stuffing, maybe under it a bag of old packing peanuts or something like that. Basically, just soft cozy stuff that insulates even if wet. Straw stays wet if it gets wet and packs down, all dried out it crumbles to powder, it sticks to their fur and gets dragged out, not comfy at all.

My doghouse has a 6x6 frame that in winter is filled with chopped foam trays that meat comes on from the store, foam egg cartons and things like that. Six inches of that makes the floor. On top of that is a piece of old carpet tacked to the top of the frame to keep it all contained. On top of that is her collection of old pillows, sweaters and an old sleeping bag. She gets in there and goes around and around and fixes it just the way she wants. She really hates when I get in to clean it up a bit cause then she has to fix it back.

I think an animal with fresh water available all the time, a full belly at night and a cozy bed is perfectly happy without heat.  

What Mark said. ^^

I've found the best straw is made up of the thicker stemmed varieties of grass that grow here. The stems are smaller and tougher than straw made from grain. They don't get crushed, so hold their insulative properties much longer than normal straw. That's what I've started using for my dogs...not that my akbash ever goes in his house 🙄

Mark Reed wrote:I don't think I would do that. On top of the possible dangers, you would have to do it on a regular basis which sounds like a bit of a pain. What I have always done for my outdoor cats and dogs is just to make sure they have a cozy, dry place out of the wind. What I think is extremely important for the coziness is a soft insulating bed.  Old wool sweaters, old pillows with synthetic stuffing, maybe under it a bag of old packing peanuts or something like that. Basically, just soft cozy stuff that insulates even if wet. Straw stays wet if it gets wet and packs down, all dried out it crumbles to powder, it sticks to their fur and gets dragged out, not comfy at all.

My doghouse has a 6x6 frame that in winter is filled with chopped foam trays that meat comes on from the store, foam egg cartons and things like that. Six inches of that makes the floor. On top of that is a piece of old carpet tacked to the top of the frame to keep it all contained. On top of that is her collection of old pillows, sweaters and an old sleeping bag. She gets in there and goes around and around and fixes it just the way she wants. She really hates when I get in to clean it up a bit cause then she has to fix it back.

I think an animal with fresh water available all the time, a full belly at night and a cozy bed is perfectly happy without heat.  

He’s in an unheated shed and has a 2 cubic foot plywood box inside the shed as a house. The box has an inch thick insulation stapled to it and is stuffed with hay. He seems just fine out there when it was in the 20s and 30s but now it’s 7 degrees and I worry about the little guy. Its not even that cold yet either. We usually get -20 or lower every winter. Should he be fine out there through all of that or should we draw a line somewhere and bring him in the house at a certain point?

Jan White wrote:I've found the best straw is made up of the thicker stemmed varieties of grass that grow here. The stems are smaller and tougher than straw made from grain. They don't get crushed, so hold their insulative properties much longer than normal straw. That's what I've started using for my dogs...not that my akbash ever goes in his house 🙄

I think I’ve got hay in there for him right now. Looked like a bale blew off of someones trailer and blew apart on the side of the road so I picked it up and saved it for the cat and chickens.

The risk of monoxide poisoning is very real with smoldering ashes. I actually studied smoldering carbon in my job and we knew when it started smoldering by the huge spike in carbon monoxide. If the area is well ventilated then it's not a problem but what's good enough to be safe? No way to know without risking the cat. The more you insulate the enclosure, the less ventilation.

Ash is indeed a very good insulator. Embers can stay hot for days inside a pile of ash that feels cool to the touch on the surface. And the pile will still be producing carbon monoxide as long as smoldering embers are present.

I personally wouldn't take the chance with my kitty.

Brody Ekberg wrote:

Mark Reed wrote:I don't think I would do that. On top of the possible dangers, you would have to do it on a regular basis which sounds like a bit of a pain. What I have always done for my outdoor cats and dogs is just to make sure they have a cozy, dry place out of the wind. What I think is extremely important for the coziness is a soft insulating bed.  Old wool sweaters, old pillows with synthetic stuffing, maybe under it a bag of old packing peanuts or something like that. Basically, just soft cozy stuff that insulates even if wet. Straw stays wet if it gets wet and packs down, all dried out it crumbles to powder, it sticks to their fur and gets dragged out, not comfy at all.

My doghouse has a 6x6 frame that in winter is filled with chopped foam trays that meat comes on from the store, foam egg cartons and things like that. Six inches of that makes the floor. On top of that is a piece of old carpet tacked to the top of the frame to keep it all contained. On top of that is her collection of old pillows, sweaters and an old sleeping bag. She gets in there and goes around and around and fixes it just the way she wants. She really hates when I get in to clean it up a bit cause then she has to fix it back.

I think an animal with fresh water available all the time, a full belly at night and a cozy bed is perfectly happy without heat.  

He’s in an unheated shed and has a 2 cubic foot plywood box inside the shed as a house. The box has an inch thick insulation stapled to it and is stuffed with hay. He seems just fine out there when it was in the 20s and 30s but now it’s 7 degrees and I worry about the little guy. Its not even that cold yet either. We usually get -20 or lower every winter. Should he be fine out there through all of that or should we draw a line somewhere and bring him in the house at a certain point?

We can get temperatures that cold but thankfully it's rare and generally just for a night or two. The line I drew that was never really crossed is if I see somebody shivering, they come in. I do admit that on rare occasion I have fixed them a warm supper and sat with them while they ate it.

I think your cat will be fine. When it's -20C here, (not so cold as you get, but still pretty cold) my dog is often still sleeping out in the open. He has a pretty thin coat for his breed, so I just feed him lots. I double his food for winter, so he gets a bit chubby and lots of energy to stay warm. When it's windy he'll sleep on the leeward side of a tree or something. He's got plenty of places to get inside, but he'll only go in in the absolute worst weather - super cold, high winds, heavy snow. Sometimes first thing in the morning I'll find him sleeping on the bare ground under a sheltered tree. I'm always amazed when he gets up and I can feel the ground is warm where he was lying.

One afternoon it started raining, then it started freezing rain, then it started snowing. Then it started getting dark. I couldn't find my dog. I went to the door and yelled and yelled and he never came. Finally, totally dark and snowing like hell I put on my boots and started out to look for him. As I stepped off the porch a big drift in the snow moved and a furry, snowy head popped out. He had been there the whole time, probably thinking will you shut up, I'm trying to take a nap.

My dog shivers a lot. I used to try to bring him in, but he wouldn't stay in for more than fifteen or twenty minutes, then he's back out, lying on the ice 🙄 My old lab was like that, too.

Another thing you can do is use mylar to reflect the cat's body heat back at it. My dog houses all have a batt of r20 insulation in the floor or a few inches of styrofoam. Their sleeping mats are a big piece of one inch closed cell foam with a removable cordura cover. Between the foam and the cordura, I have a layer of mylar. I also have floor mats on both decks with mylar underneath that the dogs can lie on.

[quote=Robin Katz]The risk of monoxide poisoning is very real with smoldering ashes. I actually studied smoldering carbon in my job and we knew when it started smoldering by the huge spike in carbon monoxide. If the area is well ventilated then it's not a problem but what's good enough to be safe? No way to know without risking the cat. The more you insulate the enclosure, the less ventilation.

Ash is indeed a very good insulator. Embers can stay hot for days inside a pile of ash that feels cool to the touch on the surface. And the pile will still be producing carbon monoxide as long as smoldering embers are present.

I personally wouldn't take the chance with my kitty.[/quote]

Very good to know. Thanks for the helpful information! The shed is maybe 10’x16’ and the roof is probably 10’ high. Its uninsulated and has a couple leaky old doors on it and a 6”x6” cat door cut into it always open. And his little cat house sits close to the doors so should have decent ventilation. Plus I would like to think that most the carbon monoxide wouldn’t find its way into his house, where the heat could radiate straight up underneath it.

Does there have to be visible smoke for there to be carbon monoxide or just the presence of heat and live embers will produce it?

Mark Reed wrote:I do admit that on rare occasion I have fixed them a warm supper and sat with them while they ate it.

Ive been warming up most of his meals! Figured the wood stove is hot so all I need to do is set his food on it for a bit before I go feed him. Surely that must be more enjoyable for him than eating it cold.

Jan White wrote:I think your cat will be fine. When it's -20C here, (not so cold as you get, but still pretty cold) my dog is often still sleeping out in the open. He has a pretty thin coat for his breed, so I just feed him lots. I double his food for winter, so he gets a bit chubby and lots of energy to stay warm. When it's windy he'll sleep on the leeward side of a tree or something. He's got plenty of places to get inside, but he'll only go in in the absolute worst weather - super cold, high winds, heavy snow. Sometimes first thing in the morning I'll find him sleeping on the bare ground under a sheltered tree. I'm always amazed when he gets up and I can feel the ground is warm where he was lying.

Thats impressive! We had a strictly outside dog as a kid (german shorthair pointer) but I always remember him sleeping inside his dog house. And in the coldest parts of winter my dad would bring him into the garage or breezeway.

Jan White wrote:Another thing you can do is use mylar to reflect the cat's body heat back at it. My dog houses all have a batt of r20 insulation in the floor or a few inches of styrofoam. Their sleeping mats are a big piece of one inch closed cell foam with a removable cordura cover. Between the foam and the cordura, I have a layer of mylar. I also have floor mats on both decks with mylar underneath that the dogs can lie on.

Good idea! I almost wrapped his house in the hide from the deer i just shot but the mylar would certainly be cleaner and not stink if it got too warm!

[quote=Brody Ekberg] Does there have to be visible smoke for there to be carbon monoxide or just the presence of heat and live embers will produce it?[/quote]

There doesn't need to be smoke for carbon monoxide to be produced. Most of what I saw with smoldering high-carbon ash was no external sign of combustion (no smoke or flame), but dig into the pile a couple of inches and there would be glowing embers.

Carbon monoxide is a production of incomplete combustion of carbon-based materials, usually due to a low oxygen environment. Complete combustion produces carbon dioxide. Inside a pile of ash there isn't much air getting in so it becomes a low-oxygen environment. Combine that with the insulation of the outer ash layer and the embers can stay lit for days, slowly cooking away and producing a lot of CO.

[quote=Robin Katz][quote=Brody Ekberg] Does there have to be visible smoke for there to be carbon monoxide or just the presence of heat and live embers will produce it?[/quote]

There doesn't need to be smoke for carbon monoxide to be produced. Most of what I saw with smoldering high-carbon ash was no external sign of combustion (no smoke or flame), but dig into the pile a couple of inches and there would be glowing embers.

Carbon monoxide is a production of incomplete combustion of carbon-based materials, usually due to a low oxygen environment. Complete combustion produces carbon dioxide. Inside a pile of ash there isn't much air getting in so it becomes a low-oxygen environment. Combine that with the insulation of the outer ash layer and the embers can stay lit for days, slowly cooking away and producing a lot of CO. [/quote]

Very good to know! Sounds like it’s probably not a great idea