Ros Harrison

Hi folks

I've got another thread going for the technical side of my rocket mass heater build, and while I did touch on the legal side, I don't want to get my hopes up in case the legality of an RMH in England is a big blocker. As the house shares a wall with the neighbors, I'd rather not risk doing anything which will invalidate my home insurance in the unlikely event the rocket does burn my house down, as it's not just my neck on the line!

I've seen various folks using rocket heaters in britain, but I've not come across any mentions of the interaction with Building Regulations. From a more general look around the internet, the main concern with any heating system that burns fuel is "Document J", and you can do the work yourself as long as the council's Building Control inspector agrees your stove or heater meets the requirements in the document. Masonry heaters, including bespoke ones, can be signed off, and there seem to be various companies building them.

Home insurers' opinions seem to range from "We won't insure you without a certificate from the council/the registered installer?" to "we won't ask about stove certificats directly, but in the small print it says any fire damage resulting from poor workmanship on a stove or other device using combustible fuel won't be covered". I don't recall having to discuss the existing gas boiler with my insurance when I originally took the policy out while buying the house, and my policy doesn't seem to reference it, so I suspect my insurance provider leans toward the latter end.

So how many of you folks using rocket heaters or similar setups around here have had the inspector in? And how many of you have talked to insurers about it?

Since I made the last post the builder confirmed what I suspected already, which is that the entire extension I'm planning to put the RMH in can't be effectively shored up, and has to come down and be rebuilt. While that completely scuppers any chance of having an RMH built before winter this year, it does offer me the chance to have the folks building the new one include a flue vent in the roof, as well as possibly an air intake point somewhere. The builder will already have building control in to sign off on the new extension, so I may get a chance to ask someone then. I might couch it in terms of a masonry heater, even if the internal section of the bell ends up being steel in my final design.

Thanks in advance!
R

Whoops, looks like images don't preview if you upload them as bitmaps - here they are as jpegs

Hi folks

I've been idly thinking about installing a fairly small rocket mass heater in the back room of my house, as it's an extension that currently doesn't have any sort of heating. I like the idea of a heated bench, and I was initially thinking of a flue buried in a cob bench, but I've recently come across the bell designs like this one from SunDogDesigns, and Batchrocket's one. They seem simpler, but I'm not 100% on the material for the bell (or the "stratification chamber" if you prefer, seeing as it's a long way from being bell-shaped at this point!).

Sundog's bench bell uses an old steel drum that's been cut open and hammered out to a wider radius curve, with cob and adobe laid on top for thermal mass. The side walls are made from cob and adobe, and originally formed part of the structure of a bench with a flue through it. The steel is presumeably to support the cob and adobe and stop the whole thing caving in under the weight of people sitting on the bench. The brick Batchrocket one uses slabs cast from refractory cement to top the bench sections of the bell, and while I may not be as slim as I once was, I doubt I'll put my backside through what's basically a paving slab any time soon, so either of those are viable options.

However, I like the idea of having the thing be at least vaguely portable, in the "take out the thermal mass and it can be moved like you'd move a big oven or other heavy household appliance" sense rather than the "move it routinely as part of day-to-day life" sense. This is both in case I ever move house, and also because I recognise my tinkering and optimising tendencies might mean I decide to rearrange the room sometime in the future.  I also have neither a source of free good-quality clay for cob nor any experience laying bricks for something like the batchrocket design. While I'm not averse to buying clay or learning bricklaying if the project calls for it, some things I do have include a welder, some level of skill with it, and access to a lot of scrap steel box section, as well as probably sheet if I ask the right people. I figure part of permaculture is working with what I can scavenge rather than shipping stuff a long way unnecessarily, so my idea for the overall structure is building a frame out of box section, covering it in sheet steel, and then having something like sand inside for thermal mass.

Where I'm less sure is in terms of the actual stuff in contact with hot gas. I'm aware steel is a biiiiiig no for risers, as the heat of even a fairly modest rocket heater will wreck a steel pipe in fairly short order, so I'll use firebrick or one of the other tried-and-tested methods for that area, but I see plenty of old oil drums used for the bell sections of RMHs in photos. I guess my question is, can I use steel for the bench section of the "bell" too? This might be slightly confusing, so I'll attach a couple of pictures to hopefully explain what I've got in mind. I'd probably go for a similar construction to the outer structure, with a frame made from box section and a sheet steel covering.

Assuming the steel can handle the temperatures in that section of the heater, how well do I need to seal the whole thing if the space around it is filled with sand? As I understand it, flues are under negative pressure due to the motion of the gas, and will therefore usually suck air in through a small leak, but is going over all the joints with high temp silicone sealant (the stuff for sealing engine exhaust systems) after I weld them a good idea to be on the safe side, or will the sand provide enough of a gas seal that I don't have to worry?

As a footnote on legality, I'm not actually sure if I'd get building regs approval for an RMH in England - if anyone knows any more about that, I'd appreciate the info. If I can't get it approved, I may just use it outdoors as a heated bench.

I picked up some seed potatoes in April that looked pretty spent, they were so shrivelled up and squishy that I almost thought they'd gone rotten. 50p for a kilo, and I got there literally as the staff at the garden centre were starting to pull down the display and throw out the last few potatoes. I filled a plastic tub halfway with compost and planted them, thinking I might get maybe one or two plants out of it. Not even a shoot showed up for three weeks, so I kinda assumed they were completely dead, and then I went away for a week and came back to a tub jammed full of plants almost two foot tall!

I filled the tub the rest of the way and kept watering, and now they're chest-high!

Now my only problem is figuring out when to harvest them, as I have no idea whether they're early or maincrop potatoes...

Despite my worries about how old they were, both the kidney beans and the black eyed ones sprouted just fine! I've mass-sown about half of them in one raised planter already, and I'm about to go and stick the rest of them in the one out front. I threw a handful in a sunny corner of the garden that's not got anything else growing in at the moment as well, just to see if they take there.

I've heard mixed things on the internet about whether black eyed beans will grow in britain, but as far as I'm concerned it's worth a shot.

So, the greywater pipe is in and I've run a couple of loads of laundry, but I actually seem to have the opposite problem to the one I was worried about! The bed drains too well, and only one end of it is even moist, despite having had 80-ish litres of water pumped onto it by the washing machine over three days!

There's quite a bit of conifer foliage buried in there along with the branches, so my hope is that as that rots down (which I assume will happen pretty fast given how wet it is) it'll start to hold enough water that some of it wicks up into the topsoil. Until then I may have to use a can or the hose to keep the soil from drying out, which isn't the worst thing in the world.

William Kellogg wrote:
Sounds like a good environment for mushrooms

I hadn't thought of growing mushrooms... I do have a shady spot to fill in this garden now I've taken out the conifer...

So, a bit of background: I just started building a small hugelkultur bed, and a lot of the advice online warns that fresh wood in a hugel can take in a lot of the nitrogen as it starts to rot. As almost all of my wood was cut within the last week, I got thinking about nitrogen fixing plants, and specifically where I could get a lot of them very quickly. That's where the beans come in. I generally have various bags of dried beans in the kitchen cupboard, so I delved around and came out with a sealed bag of red kidney beans, and an open bag of black eyed beans. I figured both of those were worth a shot, so I left a decent handful of both to soak overnight, and I'm gonna sow them once I've put the finishing touches on the hugel bed.

I don't know exactly how old either bag is, they may have been languishing in there for more than a year, so I have no idea how successful this will be. For all I know these beans have been irradiated or otherwise killed before packing, as there's no information on the packaging on whether or not they have. I'm not too fussed if they don't give me a massive yield, or even if they don't survive cooler weather, they're green manure first and a food crop second right now. If anyone UK-based has ever tried growing the KTC-branded beans you get in the "world food" aisles of supermarkets, let me know!

I'll update this thread as things progress, I might try some different beans if these don't sprout, the bags aren't expensive and I can always cook any batches that don't seem to grow.

Right, I've decided to just go for it - now i've actually built it and seen that the bed's fairly shallow and the layer of wood and branches is only about eight inches thick, I'm less worried about not having good enough drainage. If it looks like it's waterlogging the soil over winter I can always take the advice above and start dumping half the water down the sewer, or into the mini-wetland at the back of the house where I already pipe dishwasher water. I get enough rain that I don't worry about the salt buildup from the dishwasher at the moment, and the plants don't seem to mind the concentrations of stuff in the water as it comes out of the dishwasher, but throwing more water at it to dilute the salt can't hurt either.

I forgot to take a picture of the bed before I put the soil down, so here's a photo of one of the big planters I've started hugel-ifying as well! The greywater pipe's going in tomorrow, and then I guess I just start washing and see what happens!

Hi folks!

So, having finally gotten around to taking out the oversized conifers left by the previous owner (I don't understand why people plant the damn things, it's all fun and games until that "dwarf" conifer six inches from your front wall remembers it's meant to be a tree and takes off!), I've got a big pile of branches and conifer foliage. The original plan for the three-foot-by-eight patch of ground I've got out front was to put a tiered raised bed in there, watered by the greywater from my washing machine, but now I'm wondering about stacking those branches at the bottom of the raised bed to try and get some of the benefits of the rotting wood and save me a trip to the tip as well.

From what I'm seeing online, one of the main advantages of hugelkultur beds is the way they retain water, as the wood acts like a sponge once it starts to rot. Am I likely to run into an issue with waterlogging the soil if I put the washing machine water (front-loader, apparently uses 44 litres per cycle, run twice a week or so) into a bed that's got a sizeable amount of wood buried in the bottom? I'm mostly intending to plant herbs and a few pollinator-friendly plants in there. Being in England we get a fair bit of rain in winter, and I'd rather avoid dumping the washing machine water into the sewers in winter if I don't have to, partly on principle but also partly on account of the way the (shared) sewer drain overflowed with soapy water last winter when too many appliances in the terrace pumped out at once... at least it was only soap!

Thanks in advance!

R

Hi folks!

I've started taking my first steps into actual permaculture over the last few months, and after stumbling across the forums here I figured I'd say hi!

I've been doing permaculture-adjacent stuff like building cargo bikes and making stuff out of scavenged materials for years, so this was a pretty obvious progression if I'm honest.

Looking forward to meeting folks!

R