Concrete house

[Paddy]

Patrick G,

Yes, chases are critical in concrete structures. I have been in hotels and small apartments in Europe that have chases large enough to accomodate a fixed ladder. They start at the basement and go clear to the roof. I would think having all conduit go to these chases would rather simplify both building and remo work. But as you hinted, with concrete walls/floors you end up calling for a specilist in drilling holes and such for the oops factor.

With regards to Cost effective energy savings; Adding energy saving features can have deminishing returns. If your first item saves 25% of of total enery use and a second item saves 25% agian the total engery, it does not add up to 50%! I want to use 6" foam for a wall R-30, Geo-Thermal with radiant floor. Since windows account for such high losses and even the best windows have a very low R-value, I'd like to use some shutter system that has at least 2" of foam. The house will be built on our lake property with lots of South facing glass towords the lake.

A concept I've seen in Mexico is a core area that is heated/cooled and many seperate areas not. This allows for a fairly large home but as conditions are very hot or cold, the usable space is scalled down. Good example would be a sun room attached via a sliding door. I would like to expand on this concept.

 

[patrick_g]

There are other reasons besides not being a good idea for new ideas to fade out. Often some sort of crisis propels a new method to center stage but as soon as the crisis subsides or folks get used to paying $2+ for a gal of gas or whatever things revert back to what they are used to. Folks are used to stick built and most homes are stick built. In some locales cinderblock is the norm (used to be in some areas like Florida along with jalosie windows and NO A/C! Things change, often slowly. There are literally millions of Chinese living in underground homes, some whole communities are composed of undeground homes..

In the 20's there were a lot of straw bale homes built in Kansas. Straw bale construction has staged a comeback in some areas. There are still several of the original straw bale homes of Kansas still in good shape and still occupied.

One of the killers of new ideas is often a non traditional look which may sour acceptance. The big flop with Buckminster Fuller's geodesic domes, after looks, was based on a couple things. Plywood was used for the hex sections and many DIY (and contractors) didn't know how to seal the end grain of the ply and not too much later the stuff delaminated and or rotted at the seams.

Althogh the geodesic dome approximates a sphere which is the least surface area (materials) for the greatest enclosed volume, it doesn't lend itself to conventional floorplans and furniture arrrangement and there can be a lot of waste space. I have seen concrete dome homes that have all the shortcomings of the socker ball design and I have seen concrete dome homes with vertical walls and square corners and the only domed part is the ceiling. Great compromise, terrific strength, economical, and not butt ugly.

Paddy, I used Panel deck brand forms for the overhead flat work and am pleased wth the results. They are tongue and groove in 2 ft sections. They have two A/C ducts molded in each section and some smaller chases for running pipes or wires (I'd still use conduit in their holes.) I hired a Mech Eng to colaborate on and take credit for the design of the penetrations for stairwells and provide the PE stamp (and E&O Insurance.)

I did not use any waterproof coating or membrane in the basement wall construction. The basement floor is over a 16 inch washed septic gravel bed that is topped with 2 inch rigid foam and covered with Stego Wrap (HD plastic sheet.) There is a French drain all around the outside of the foundatioin at the top of the foundation (about 24 inches below the floor) and there is a separate French drain all around the foundation on the inside (just in case.)

The basement walls have a product called InsulDrain on the outside. Insuldrain is tongue and groove 4x8 sheets of rigid foam insulatiion with vertical and horizontal water channels on one side that are covered by tyvec filter cloth. The filter cloth side is turned away from the wall toward the backfill. I back filled with gravel and sand. My cast walls used snap ties so there are plenty of small leakage channels through the walls plus all the microcracks that develop.

The Insuldrain prevents a head of water next to the wall by providing a drain path to the French drain. The water table at the site of the basement was about 6 ft from the surface so the basement floor is about 6 ft or so "under water." The French drains have drained continuously since installation. Of course the outer drain does the most and the inner drain gets a little once in a while. I have taped plastic sheeting to the floor and walls of the basement at various locations
to test for evaporation of water from the surface of the concrete which would preclude certian wall or floor coverings. Even prolonged tests showed no sign of moisture, not the least darkening of the concrete that I covered, even after letting the test run for a week.

I was advised by my soils engineer conlsultant that instead of trying to water proof and have a coating or membrane failure to design to handle the water in a passive manner (I don't have or need a sump pump.)

My basement is a walkout basement and the French drains drain to daylight (goes in a backyard pond.)

I also considered various ways to have a bathroom in the basement and ended up with a 500 gal septic tank buried out back of the basement. Its output gravities to a holding tank which has a pump to empty it uphill into the shared leach lines used for the output of the 1000 gal septic tank for the rest of the house. I used the Infiltrator system of plastic domes instead of septic gravel in the leach lines. The Infiltrator system has terrific surge capacity. It is covered with geotextile to prevent future problems with fines in the soil.

Pat

 

[Paddy]

Eddie,

I think the reason we don't see concrete construction here is because when homes were first built in the US, wood was king. We as a nation have just kept doing that way. I travel quite a bit and the US appears to be the only place where wood homes dominate the market. Though wood has gone up in price, Concrete homes do cost more to build than traditional stick built homes. But it's hard to compare the cost because you get quite a bit for that extra money. Fire proof structure, rot/decay proof, storm resistance, sound proof and Thermal mass benifits (the claims you read about need carefull review for your lacal). If you read the Concrete homes or ICF sites, they claim a very small additonal cost. The main cost issue for most folks going concrete is the lack of experinced builders. This adds cost if you can even find some to build for you! I had done a bit of research in my local area. Every time I asked who was the best concrete forming guy in town, I got the same answer. So I call the guy so I can get in line for the "best contractor". Well, he's not interested in doing any thing out of the norm. He has a full plate just pouring bacement walls. His crew is trained, so why make life hard?? I was able to contact a small company whom I've known the owner for years. He has done a few CIF and is very interested in the concrete home idea. Most important, he sees the project as an opportunity not some odd ball project. I want to have the home built Time & Material. this may sound odd but I was in the construction industry for 15 years. If we ever saw a "job" with question. just bid double it to make them "go away" or "make good money". I trust my builder, and will request weekly bills to keep up on labor costs. I travel a bit for weeks at a time, so I need someone on site to have the ability to spend my money when questions come up. I like the phrase, "If it were your house...". I'd rather the builder think on how it is done right, than how can I catch up on my bid.

As far as the finer details how do walls tie in to ceilings, I will use multi resources;

1. Insul-deck should be able to provide wall/ceilling/wall joint details
2. I work with an Engineering University in Prague for material testing for my real job. their lead researcher's specility is concrete structures. He told me he will gladly review my plans.
3. I'll have plans reviewed by an Engineer. I'm considering having it done in Europe where concrete homes are as common to them as wood structures are to us!

This is a big project. My first house I started when I was 21, well bought the 10 ac and built a shack! Over time I built a saw mill and built a 3500 sq-ft timber frame home from the trees on the land. I'm 46 and the three kids are off at school. We work from the home and my lovely wife and I have a bit a spare time to over see my GC. The new home will be about 30 min from our home we currently live in.

Eddie, When I start, I'll keep taking/posting photos as you have with your "Building a Lake" post that I have enjoyed so much

Patrick

 

[Paddy]

Patrick G,

Sounds like you were happy with Panel deck. I'll give them a second look. As Eddie asked, How did they reccomend the conection from lower wall to floor and then the IDCF's? I would think cold joints ending at the top of the wall, just rough? I'm not to concerned with this issue above grade.

As far as your coments to why we build with wood and adjust to crisis is straght on. We in the US just havn't seen a long duration of high energy costs. We always manage to endure the high cost untill all is OK again. This lastest SUV wave is a good example. How quick we forget!

 

[EddieWalker]

Patrick,

I used to live in Cameroun and Indonesia, I've been through Europe and Asia with a few trips to Australia and New Zealand. One of the things I don't like about concrete, or block homes is from seeing the homes in those countries and how inferior they apear to me when compared to what we have here in this country. I don't think it's a craftsman issue, but that our homes are wood framed with sheetrock interior walls.

A home should have a warm feel to it. Hotels don't have this "feel" and in almost 30 countries, I've never been in a home where I felt that feeling.

My family is all over Canada and they all have basements. To me, the closest way to relate to the homes I've been in overseas is to compare them to those basements. It's not that they are cold in tempature, but cold in feeling. I'm sorry I'm not able to express it any better than that, but to me, this is probaby the biggest reason concrete homes are so rarely built.

Warehouses are built from concrete all the time, as are commercial buildings. I know it's not new technology, but people dictate the market and so far it's just not something that gives the warm and fuzzies.

Your method has the potential to be different. I would love to have a solid, bug proof, weather proof highly insulated home like what you are going to build. There can be nothing better than to build a home and know it will never rot, burn or have termites. If you can do it for a comparable price to timber frame, than I'd be very interested in doing the same thing myself.

I'm not against new ideas or technology at all. In fact, I'd love to be involved in trying these things out. I just don't want to spend my money on them until I'm convinced it's a solid idea and method. People will buy quality no matter how its built. Dome homes are not quality on a whole. I agree with Pat that some are very nice and better then most stick built homes. I just don't want to try and sell one that I've spent allot of money building myself.

There is nothing I'd enjoy more than to follow along as you build this home.

Thank you,
Eddie

 

[40Kchicks]

Do you have any specific reason why you want a foam core wall instead of going with an ICF form wall. This last summer I built what I believe to be the first ICF chicken barns in the US. They are 60’X500’ and we built 4 of them. I found the construction of these ICF walls very easy plus the results were a very solid wall.

This next summer we are going to build a two story house out with the same ICF product. We are also planning on pouring concrete floors using the hambro system and radiant tube heating.

I really like the concrete homes and encourage you to build the best quality home you can the way you want it. I was just curious if there was something you didn’t like about ICF.

Eric

 

[Paddy]

40k,

It's not that I dislike ICFs but CIC has beter Thermal traits. Check out the link second from the top on my first post. Also, solid interior and exterior walls. The Foam in and out need to be covered by sheet rock or siding. What did you cover you walls with?

Patrick

 

[gemini5362]

Paddy I am also wondering about the advantage of the way you are going to build versus the foam concrete foam house. Are you going to use rebar in your walls. How thick are your concrete walls going to be. With the foam concrete foam you get 8 inches of steel reinforced concrete for a wall. Works pretty well in tornado country from my research. You mentioned solid interior walls you can do the same with the FCF wall just put up the blocks for interior walls and fill them with concrete. Most people do not do this because of the expense. What a Lot of them do is maybe put up forms around a bathroom or large closet. they bend their rebar over 90 degrees at the top. then they form up a place to poor a top over the room and add rebar to that also this gives them a room that is concrete steel reinforced in case of a tornado. With the FCF ( foam concrete foam ) walls you just cut a channel in the interior foam to run your wireing. most of the forms have a steel or plastic piece the runs the length of the foam on 12 inch centers this is to secure sheetrock or sideing too. To me this is a simpler medium for most of the things you do to a house. Are you going to just have the outside of your house left concrete. I am sure my wife would just say no to that if I tried it.
I am looking forward to your responses in here of the advantage of doing it the way you described

 

[Paddy]

Gemini,


If you go to the site I posted called "themal mass discussion" in my first post, you will see a study summary from a ORNL, Oak Ridge National labs. The facility is packed with Phd's who study energy conservation based on construction methods. The study consisted of 4 concrete foam combinations. The CF, FC, FCF and CFC. The best result was Concrete on the inside of the wall with foam on the outside. The second best was Concrete/Foam/Concrete, but very close to the best. In far third place was F/C/F (ICF) and last was Foam on the inside and Concrete on the outside. In the study and experiments, there was a big divide in the results. The least faverable were the ones with foam on the inside the structure.

Yes I will use R-bar. As far as Concrete thickness, on the basement level I will likely need 8-10 in, where as the top level will likely need 5-6". The inner concrete panel is the true structural wall, the outer is more of a Thermal buffer, fire protection, siding like brick. (I will stucco my walls). This outside panel will only need to be 4". Any thinner, and it will be diff to pour/consolidate. So think of the panel as 8"-Structure/6"-Insulation/4"-veneer.

When I state, soilid interior walls, I mean the inner surface of the exterior walls, I don't want foam inside due to the Thermal explanation above. I will use a skim coat of plaster for the inside of the walls.

As far as the exterior "look". This post was started from a Thermal and structral base. The design will be a Spanish vila, or Itailain vila. Stuco surface, stone lentals-arches around windows, red tereacota roof tiles. Porches will have large oak timbers framing the roofs. Alot of wrought iron window and hand rail details. I think most will consider this type of home quite attractive. I just don't care for the vinyl siding with a bit of brick along the front look that is used in most homes today. (not tring to start a flame war on siding
I will try to dig in my photo files to find a good example of the style of design

 

[EddieWalker]

Paddy,

Being from California, I can tell you that the Spanish Villa look is one I grew up with and have always liked. Especialy if you carry the theme through the entire house, but in moderation. Some of the homes I've been in can realy go over the top with there tile patterns and colors. hahahaha But that's just me.

I love the exposed beems and iron part of it the best!!!!

Given a choice, I'd personally go with the Tuscony style found in wineries in the Napa Valley, but that would be because I've rarely seen it and think it would be allot of fun.

Your project is sounding like allot of fun. Do you have a start date? Are the floor plans drawn? What will the interior walls be built of?

Thanks,
Eddie