jason edward

Jay, thanks for your insight. I am planning on using "straw cob", nearly everything i've seen on cob is that form.

Kate, it's good to see others doing the same thing. Simon Dale's houses sure are inspiring. I'm looking forward to seeing what you do as well. I hope it catches on. We should begin breaking ground on the building by June. Our access road onto the property will be started in the next couple weeks, and then the real fun begins!

Has anyone tried installing a cooking surface on the top of the burn chamber? I was thinking that instead of firebrick and cob, I'd replace the top of the burn chamber with an iron or steel plate for cooking on, and the oven on top of the riser. Or possibly the cook top above the exhaust (saw a design similar to this on this forum) Any thoughts? Thanks!

I do know the difference between insulation and thermal mass. I've also lived here my entire life and know about the climate...that being said...

I've maybe misled you about the amount of glazing in that wall. It's not really excessive, much of the glass will be in the sunspace. My design conforms to many other PS designs out there.

It's very important for that south facing wall to act as TM, because the sunspace/green house on the other side of it also needs to be heated efficiently. The plan is to run a rocket mass heater along that wall as well, on the suspace side with benches for seed starting above, and on the inside, nice window seats. I don't see the benefit of insulating between the spaces when both need to stay warm. We'll also have another mass heater that will double as our cookstove and brick oven in the kitchen for winter cooking (we're building a summer kitchen so we don't heat the house up with our cooking). We could also add some water bottles in the wall as well, while studing for this design I read that water walls make extremely good thermal mass.

I was pretty dead-set on using straw bales until just the last couple of weeks when I started thinking about the sunspace on the other side of the wall and keeping it warm in the winter. We will probably use them on the stem wall of the sunspace, and the cob wall above the 8 ft line. I should mention that the wall is 12 ft high, to accommodate the height of the reciprocal roof in the loft area where the kids' rooms will be. That will help keep the heat that rises from leaching through the walls up there.

I hope someone with real experience in cob building pipes up, as we're both hypothesizing here...

michael Egan wrote:Hi Jason
I've built a number of rocket stoves and a couple of mass heaters and am contemplating a house like yours on our farm in central illinois so I'm very interested in following your progress and learning from you and would be happy to exchange ideas as you and we move forward.

You might want to try mixing some vermiculite into the south facing cob to get some air into the wall which would lighten the mass but decrease the transfer which in your case is the cold. I'm sure you'll find ways to increase your insulation in the coldest months-- straw bales stacked up temporarily against a cold outside wall, curtains blankets or panels inside-- but vermiculite should help. I've bought mine at Menards. Any way you can trap air into your mass, maybe even beer bottles. Good luck with your work, sounds good.

Michael

I repeated this post in the Cob forum as well, which is turning up some discussion on the topic.

I've looked into the vermiculite idea, and it sounds pretty good.

I am also very interested in the exchange of ideas...when are you starting construction? Do you have any experience in this type of building, outside of the rockets?

Best of luck to you as well! I'm sure we'll be in touch.

Another thing that just occured to me. While trying to find the answer to my own ? yesterday, I saw a statistic that a basic cob mixture has a value of R30 by itself, and you can add some other things to increase the insulative value. Another thing is the windows....with that much glazing, it sort of makes no real difference as to which method we choose...thoughts, Brian? You seem to have pretty broad knowledge on the insulating subject.

I've heard of R values being much higher with strawbale walls than you're suggesting, Brian, a minimum of R40, anywhere from R1.5 to R3 per inch of strawbale thickiness (from a study done by the State of Michigan). The greenhouse will be similar to the Undercroft, another of Simon Dale's houses. We like the look and the accesibility, and we'll be able to open them up for air flow and help to keep our heat inside in the winter, essentially turning the wall in question into a trombe wall (this term I found in "The Hand Sculpted House")...with our passive solar design the sun won't shine on that thermal mass during the hot part of the year. Also, regarding the air-tight-ness, we'll be installing earthtubes for fresh air circulation, so not air-tight for air quality and the draw of the R.M.H. Keep in mind that this will be an earth-sheltered home, so we'll only be heating from around 50 degrees or so, much more economical than the 2X4 stick frames in the area. Thanks for the input, every bit helps!

We will be doing it as authentic as possible. I'll use traditional joinery techniques around the top of the frame but we'll use metal fasteners only to attach the roundwood timbers to the pylons so we won't have to embed the wood in the ground, or possibly setting metal tubes into the concrete that the butt ends of the logs can sit in. The pylons are only place we intend to use concrete. As for the rest of the structure, we don't have enough suitable trees on the land to do the frame, so we'll have to order those from a local guy. On the other hand, I can eliminate the timber framed section on the south wall if we use cob, so that'll cut down on the outsourcing of materials. And our location gives us an abundance of clay, so that's a great resource. Thanks for your input. I've been leaning that way myself, but it never hurts to have a few other brains weigh in.

This is a post I've already posted in other topics, but just so I don't miss anyone...

First time poster, long time fan here...This site is a GOLD MINE. My wife and I just purchased 10 acres and are building an earth-sheltered home this spring as soon as the ground thaws on the south shore of Lake Superior in NW Wisconsin. I've been planning the house for months. We were originally planning to build a dome home and came across Simon Dale's site during our research and fell in love with the idea. Although we've had to alter many parts of the design to try to stay within the confines of the building code, we have decided to do the timber frame and reciprocal roof living roof, rubble trench/frost protected shallow footings with 20 foot wing insulation on the south side, leading to the drain tile that encircles the entire umbrella of the building. We plan on using earthbags to build a retaining wall for our earth berm on the north, east and west sides and using them for the foundation/stem wall on the south side. Everything inside will be on a gravel pad with a cob floor (similar to slab-on-grade) for thermal mass. My question (if anyone can help) is whether or not to use strawbales with cob plaster or just plain cob on the south side? We have long, cold winters and we'll have a LOT of windows on that side of the house, so I don't know if there will be any REAL advantage as far as insulative value (not to mention the cost of shipping and trying to find them this time of year) to using straw bales as per my original design. We also plan on building a green house on the outside of that wall probably next spring. With cob, we could run a rocket mass heater through that wall...Anyone have any insight? Thanks for reading!

First time poster, long time fan here...This site is a GOLD MINE. My wife and I just purchased 10 acres and are building an earth-sheltered home this spring as soon as the ground thaws on the south shore of Lake Superior in NW Wisconsin. I've been planning the house for months. We were originally planning to build a dome home and came across Simon Dale's site during our research and fell in love with the idea. Although we've had to alter many parts of the design to try to stay within the confines of the building code, we have decided to do the timber frame and reciprocal roof living roof, rubble trench/frost protected shallow footings with 20 foot wing insulation on the south side, leading to the drain tile that encircles the entire umbrella of the building. We plan on using earthbags to build a retaining wall for our earth berm on the north, east and west sides and using them for the foundation/stem wall on the south side. Everything inside will be on a gravel pad with a cob floor (similar to slab-on-grade) for thermal mass. My question (if anyone can help) is whether or not to use strawbales with cob plaster or just plain cob on the south side? We have long, cold winters and we'll have a LOT of windows on that side of the house, so I don't know if there will be any REAL advantage as far as insulative value (not to mention the cost of shipping and trying to find them this time of year) to using straw bales as per my original design. We also plan on building a green house on the outside of that wall probably next spring. With cob, we could run a rocket mass heater through that wall...Anyone have any insight? Thanks for reading!

First time poster, long time fan here...This site is a GOLD MINE. My wife and I just purchased 10 acres and are building an earth-sheltered home this spring as soon as the ground thaws on the south shore of Lake Superior in NW Wisconsin. I've been planning the house for months. We were originally planning to build a dome home and came across Simon Dale's site during our research and fell in love with the idea. Although we've had to alter many parts of the design to try to stay within the confines of the building code, we have decided to do the timber frame and reciprocal roof living roof, rubble trench/frost protected shallow footings with 20 foot wing insulation on the south side, leading to the drain tile that encircles the entire umbrella of the building. We plan on using earthbags to build a retaining wall for our earth berm on the north, east and west sides and using them for the foundation/stem wall on the south side. Everything inside will be on a gravel pad with a cob floor (similar to slab-on-grade) for thermal mass. My question (if anyone can help) is whether or not to use strawbales with cob plaster or just plain cob on the south side? We have long, cold winters and we'll have a LOT of windows on that side of the house, so I don't know if there will be any REAL advantage as far as insulative value (not to mention the cost of shipping and trying to find them this time of year) to using straw bales as per my original design. We also plan on building a green house on the outside of that wall probably next spring. With cob, we could run a rocket mass heater through that wall...Anyone have any insight? Thanks for reading!