Miscellaneous Questions about Building

John Connell founded the Yestermorrow Design/Build School in 1980 and the Yestermorrow Building Group Inc. (later to become 2morrow Studio in 1982.) He taught at Yale's school of architecture for five years after which he authored the book Homing Instinct: Using Your Lifestyle to Design & Build Your Own Home, McGraw Hill, 2000. Besides teaching he is currently designing green homes that tell "stories", design/building treehouses for handicapped children, and animating short films. 2morrow Studio puts into actual practice the design/build philosophy taught at the Yestermorrow School. A small design/build firm in Vermont, 2morrow Studio works with residential and small commercial clientele interested in integrated energy-efficient architecture using the latest green and sustainable methodologies. Besides architectural design, Connell is an experienced team builder, group facilitator and educational program designer. The Yestermorrow School teaches people how to plan, design, build or renovate their own homes. It is staffed by over 40 architects, builders and artisans from all over the United States who believe that the way to improve the built and natural environments is to re-involve people in vernacular architecture.

Questions and Answers

Q: What alternatives are there to using drywall? I live in the pacific northwest and want to convert part of our shop into a yoga studio.

A: Bamboo board, hayboard, plaster, wood panel and even properly specified plywood are all reasonable alternatives to plain gypsum board. Or, gypsum board can be used and covered with fabric, imaginative paint treatments or, last of all, wallpaper.
I've had the most fun with gyp board by applying additional layers in patterns. Sometimes I layer it as thick as four layers. Mounted on a flakeboard backing this gives an incredible design effect that is flexible, inexpensive, and sustainable.

Q: Although I have never built an entire house by myself, I have been on crews that built many large conventional homes and I have undertaken some large projects by myself. I am young, strong, and healthy, am into a regular exercise regime of mountain biking, rock climbing, and light weight lifting. I just wanted to share my gratitude with you for what you have done with your home and the hard work you put into it, more people need to learn how to build earth friendly houses. As vegans we are very aware of the earth and how precious her resources truly are.

A: (Kelly) I appreciate hearing of your interest in sustainable architecture and the road that has brought you to this interest. From your description of your experience, I would say that you should have little trouble being an owner/builder, and I encourage you to follow your dream to completion; few things can be more satisfying.

Q: My question is simple - can I build an alternative house for my family? Some details: 1. We live in western Pennsylvania - 1/2 northeast of Pittsburgh, yet still very rural.2. We have five kids - 3 girls and two boys; plus the required dog and cat.3. I am a pastor of a small church - i.e., low income. 4. We home school; in addition, I work out of the home. As well, we use our home for lots of hospitality. I.e., living space is a big need. 5. I am familiar with the building process - 8 years solid real estate and appraisal experience, plus one nightmare of a home building project (we lost quite a bit via a disreputable contractor). 6. We may be able to secure some land inexpensively, and use that as collateral for financing. 7. Do-it-yourself home building is somewhat common around here. Taking a year or two to build is no biggie. So, we'd like to build big, cheap, and unique. (The kids would love to live in a hobbit hole, but I'm not about to walk around bumping my head all the time.) So, is it do-able? How do I educate myself? What would be the most cost-effective method(s) for my area?

A: (Kelly) I don't see any reason why you shouldn't be able to build your dream alternative home. I built mine pretty much single-handedly in about three years. I always advise people to design their house to fit the particular site, so this might be one of your first priorities: acquire the land where you want to build.

There are lots of ways to become more educated about natural building techniques. Researching the internet, as you have been doing is a good start. There are many books and videos that can help; several of these are available at this website. Also there are lots of seminars and workshops, especially in the summer, that can give you hands-on experience in a variety of building techniques. You might take a look at those listed on the news page. Lastly, natural building can take any shape that you like; Hobbit holes do not necessarily require one to stoop!

Q: I am purchasing a lot on the big island of Hawaii, near Hilo. I am interested in building a Green home, but only have a shoestring budget (around 85K). What do you suggest?

A: (Kelly) I suspect that the cheapest way to build in Hawaii is minimally. The climate there generally just requires a roof overhead and screens to keep the bugs out. Use local, natural, or recycled materials as much as possible, do most of the work yourself, and keep it small. Actually, for 85K you should be able to build a palace. I built my earthbag/papercrete house (1200 sf) for about 23K (and about 3 years of labor).

Q: I am seriously interested in the treehouse concept for construction of small rental units to cater to our increasing tourist influx. I live in the N.Ga. Mtns and have been building homes for several years but would really like to pursue this avenue. Having dealt with inspectors before that just can't seem to think outside the box, I've concluded the easiest approach would be to elevate the platforms on stilts to begin with and try to graduate into the full blown support using the abundant white & red oaks, fir trees and other large diameter trees. The stilts I know will solve the problem but, it seems to really kill the effect I am trying to capture. I am tired of seeing the mtn. sides raped with Dozers in order to put a basement in to build houses. Any comments or direction would be grateful. I have searched the web, researched the codes but can't seem to find a straight forward approach to this so as to submit to the locals without being shot down or spend a small fortune on engineering and then still be turn downed.

A: At this point we have almost four serious treehouse structures under our belt, with the last two being built in Connecticut, a state rich with code officials and loads of local ordinances. I say “almost” because we’re still finishing the last one, which is part of a luxury resort scheduled to open in January. We’ve built in pines, red maples and oaks – oaks are definitely the very best. Pines are the worst. Well, actually, elevated platforms are the very very worst. We’ve built to comply with ADA (Americans Disability Act) and we’ve built to comply with all sorts of building, fire and environmental codes. Is there a trick? I’m not sure. I think it helps that I’m an architect who spent 20 years wearing a nail apron. I know a bit about how to work with inspectors. I think it helps that our award winning arborist is renown from coast to coast and that the trees are actually better off after we’ve executed his prescriptions. We also work with an engineer who thinks the entire concept is a no-brainer….of course most of his real work is water slides, so you have to remember his perspective. There are some additional tricks we’ve learned (developed) for dealing with multiple tree structures, heating, AC, lifting heavy loads, and supporting heavy loads – like fireplaces. But we don’t know everything; certainly not! Every tree is different and each one is a new game.

I should also add that we have been able to make each treehouse more sustainable than the last. There is no better way to teach people about the importance of sustainable design than getting them way up in a tree. What could be more clear? - if we don’t accommodate our natural surroundings (the trees), we will inadvertently destroy them. If our tree sickens and dies, our building will also perish along with any profitable activity or fun we had planned for it.

Currently we’re very optimistic about designing a demonstration treehouse for a 90 acre woods owned by the city of Hamden in Connecticut. Those trying to preserve this little tract of trees want a treehouse which expresses and educates to be the centerpiece of their preserve. We are collaborating with the biology department of the local college to create placards and built-in demonstrations that will help illuminate the natural principles upon which any treehouse – indeed any building­ ­- is based.

Al, if you’re serious about treehouses, you can shorten your learning curve considerably by taking advantage of ours. There are a few ways to do this. The most straight forward approach would be to hire us as architects. That way you get both engineering, tree assessment and design in one coherent package. We might also be able to help you with the construction though I should think that would be your department. In any event, we’re not really as expensive as you might think….or maybe we are. I’m not sure what you mean when you say “a fortune on engineering”. But if you want to do it all yourself, then I suggest you go to the Yestermorrow School for a Sustainable Treehouse Workshop. We teach one every other year for avid do-it-yourselfers. These are mostly attended by experienced builders like yourself, as well as a few fathers using their 6 year olds as an excuse to realize a long overdue dream.

Q: My husband is trying to "break into" the alternative building industry. He has no experience in alternative building, but is fascinated by it and is very enthusiastic about getting into the field. (If it counts for anything, he helped his parents build their log home and has been making pottery most of his life.) Try as I might, I cannot find online listings of companies that build alternative homes. Is there such a list, or do you know of some companies that let hard-working and enthusiastic people "break in"?

A: You are a good partner to help your husband in this laudable redirection of his career.  I'm sure there are many lists of construction firms that specialize in alternative design and construction, but they will all be local (or at best regional).  I suggest you contact your local chapter of the NAHB (National Association of Home Builders) and see if they have such a list.  Alternatively, you might contact/email the COTE (Committee on the Environment), an AIA committee focused on enlightened and sustainable building practices. Lastly, there may be a group of similar minded folks involved with your local Habitat for Humanity.  I know they're always trying to make their buildings greener.

Q and A (Kelly): How do you find land that isn't part of some developers master plan?

There are lots of ways to find land for sale: check with realtors, look at want ads, drive around looking in areas that interest you and look for signs, ask people in neighborhoods where you would like to live.

Is it wise to buy land and build a super-green home?

Buying land first and then designing your house to fit that land is the best way to go!

Are there kickbacks from the gov't for those who build/inhabit green homes - like those who are driving hybrid cars? Do we get tax breaks?

Such tax breaks are usually administered by the state, and sometimes by the Federal government. Check with these authorities. It is more common for such incentives to be for adding solar panels than for actually building a house, but this is also possible.

Q: My mother has had a long-time dream of owning her of bed and breakfast inn, and I've told her before she should build her own and make it an eco/green home because that could be a draw for customers/inn-guests, plus then she could make her own dream home and since it would double as a business it would help the property pay for itself. I've also told her how going green could be cheaper than other methods of building or purchasing something already constructed.

At some point last year, in one of my regular visits to your site, I found a link to another site in which a man built his own small home for some incredibly small amount. $10,000 maybe? I seem to be having trouble relocating it specifically on your site.

A: I have some information up about the house that I built on the earthbag page , which cost about $35,000, with my doing most of the labor. I have a DVD about this project listed on that page. There are other building techniques that can be done by owner/builders for very little money: Notably, adobe, cob, cordwood, and something called PSP, as described in Mike Oehler's The $50 and Up Underground House book  .

The secret to keeping costs down are to do most of the work yourself, be on the alert for second-hand deals, and keep the design compact; with this in mind, most any method can be affordable. You are right that the public loves to spend time in well-designed and executed natural homes, so your mother would certainly benefit by following your advise.

Q: We are in the planning stage of our home. This will be our first basement, and we are wanting to do it the HEALTHIEST way possible. First of all, we live in the foothills of North Carolina, so we have relatively mild winters, but humid summers. We have been exposed to numerous ideas...such as, a prefabricated polystyrene wall structure, filled with concrete in the middle; you have to put gypsum board, or the like, on the interior walls, to cover the foam board. I am concerned about the chemical used in making this wall, which is primarily made of benzene. I was poisoned by UFFI foam, which is now banned by the FDA, I was told. Would the use of gypsum board protect the basement? Also, we wanted to do a rigid board insulation on the basement floor over the gravel, to assist the plastic barrier, in moisture control.
What are your ideas of a healthy basement, with regard to moisture and energy loss control ?

A: Sorry to be brief, but my work is spiraling out of control. Check out Superior Walls. Great product. The gypsum board merely protects the foam in case of fire.  The issue of moisture and energy loss is more complex for buildings in your climate than can be adequately addressed in an email.  Get a professional or specialist on the case!

Q: I'm considering a lightweight concrete counter top as opposed to granite, tile, wood, etc. Is there a specific mixture I should use, or issues to watch out for (moisture around a sink, supports, etc.)

A (Kelly): I have seen some beautifully finished concrete countertops, but they have all been standard concrete rather than light-weight aggregates as far as I know. Light-weight aggregates would not be as durable over time. I suggest that you consult with a specialist for this project.

Q: I'm in Bilox,i Mississippi working here since the storm Katrina hit 7 months ago. The storm destroyed a lot of things including damage to the protected live oaks here. The tree's are around 400 to 600 yrs old. Not many but a few have fallen down since the storm. I have possession of one that's about 8ft wide. I can't bring this tree to a mill because of all the damage around here, so the only way I could harvest the tree, would be for me to hire someone to cut it with a chainsaw cookie style, in 3 to 4 inch slabs, table tops. My fear is that after cutting them, what do I do next? What scares me is not knowing how to dry them, to prevent a lot of cracking. I would hate to invest a lot of money only for them to fall apart after drying. Maybe this is foolish talk, but I have never done anything like this. My question to you, Is there anything I can put on these slabs to prevent bad cracking? I'm not even sure if live oak is known for cracking a lot. Also, do you think this venture is even worth me messing with? I'm not sure. In my mind I imagine me making a lot of money with these ancient tree's sold as custom table tops, not sure I guess.

A: Boy Seth, that's beyond anything I've ever worked with - 8 feet!  My suggestion would be to contact the people at Fine Woodworking magazine.  I know they have a web site and a chat room.  Surely one of their experts will tell you how to mill and dry that old wolf.

Q: I'm really new to "green building" yet have been interested in it for a very long time. In the past 18 months, my home (a mobile home) was damaged by a tornado (knocked off it's foundation). Due to damage to the structure, it is no longer habitable. We do own it though, and it is still standing. Both my husband and myself are very artistic and creative people, on a VERY tight budget, but with a lot of time as we both stay home with our kids, home school, etc. We have about a 1/2 acre that we can build on. My question is this, since neither my husband nor myself have any architecture/contractor license, how could we go about building a home ourselves? I would like to salvage as much from my mobile home as possible (windows, plumbing fixtures, electrical box, interior doors, etc.). Since we also live in an area that is somewhat prone to hurricanes (and two tornados in the last 6 1/2 years) we are also concerned with very sturdy home building. I've looked deeply into rammed earth and sandbags, any other ideas? I'm big into solar heating/cooling, recycling, and that sort of thing. Open to any and all ideas here.

A: I don't want to "beat my own drum" but you really sound like a perfect candidate for a class at the Yestermorrow Design/Build School ( www.yestermorrow.org ). Your dream of rebuilding is entirely possible but you want to have some ongoing help to keep you from making some big (and possibly dangerous) mistakes.  Yestermorrow is the perfect place.  Not only can you spend a few days there with professionals looking at your specific design/build situation but even after you leave, you will have an ongoing relationship that you can fall back on as unforeseen questions arise.

Q: I've taken three courses at Yestermorrow so far and would love to take more. One thing I could use help with, however, is getting an idea of structural requirements for supporting a living roof in an area with a 70 lb. snow load (yes, in Vermont). I realize I will need a structural engineer to ensure that my plans are safe, but I'd like to at least have an idea of whether I'm in the ballpark (and to get an idea of cost). Will 8x12" Hemlock do the job while spanning 10 or 20 feet? Overkill? Or should I look into trusses? I've researched lots of formulas for determining span and so forth and, I must say, I'm really lost. Most formulas assume no more than 40 lbs. of living load.

A: I couldn't (wouldn't!) hazard a guess without at least seeing a drawing.  There are so many "unknowns" in your description that I would really be sticking my head out to say anything.  I need to know the total size and dimensions of the living roof; what's above it; what's below it and what the spacing would be between the 8x10's.  I really need to see a sketch of the whole deal to determine what might be even close to the Ball Park. Sadly, as a professional architect, I am liable for any structural information I might put in print.  So even with all the above information, I'm not likely to give you much more than - "yes, you're in the ball park", or "no, you're not".  Since you already know you need an engineer, why not use this first guestimation as an excuse to go shopping?

C: I appreciate your liability concerns.  The reason I'm resisting hiring a structural engineer right now is that my design changes as I investigate the pros and cons of various building materials and processes.  As money is a serious concern, I'd rather consult an engineer when the structure is essentially complete on paper.  One of my few frustrations with Yestermorrow is that the instructors gave us some wonderful ideas, such as living roofs, but were unable to cite examples of their own.  So, sometimes they could not answer questions specifically enough to enable us to build them.

Q: I was wondering what you thought of timber houses. Do you think they are better than brick houses?

A: In the interest of brevity, let me just say that there is no way to rate Timber over Brick without knowing the situation, the site, the budget, and the floorplan. Each are ideal for certain situations and inappropriate for others. But they cost about the same, and you couldn't ask for two more beautiful building technologies to choose between. Can't go too far wrong with either. Build to Last!

Q: I live in CT in a conventional 1950's ranch home (w/ attic and basement). Growing up I lived for some time in a passive solar envelope home (in WV). I'm curious about the possibility to retrofit a conventional home to passive solar envelope. Do you know of anyone who is doing this?

A: I'm not aware of anyone who does that sort of retrofit, inside CT or out. If I understand you correctly, you grew up in what was sometimes referred to as a "double envelope" house. These usually had a very large stone filled heat storage in the basement. Do you have room for that? Also, these houses fell out of favor because it was discovered that they didn't work really the way they were advertised (by a guy named Bulter, I believe). The reality turned out to be that they were just so tight (one house built entirely within another) that the air changes were reduced to a point where the heat loss was very much reduced. Today this is accomplished in much more affordable ways that use less lumber and other resources. There are loads of green designers and builders in CT, mostly in and around the New Haven area. But I doubt they would be advocating the retrofit described above (if indeed that's what you have in mind).

Q: I would like to know if building sustainable, natural treehouses for children is possible. I was thinking of building some in our neighborhood, but can't find any blueprints or plans. Do you have any ideas?

A: Sustainable treehouses, by definition, must be tailored to the trees that they are built in.  This is how they are able to work in concert with the tree's health and not against it.  Properly designed, a treehouse can actually extend the life of the trees in which it's built.  (We provide such designs if you should care to discuss this further.)  I invite you to look at some of our larger projects at   www.2morrowstudio.com but keep in mind that these are the biggest of the big.  We encourage people to build much smaller whenever possible.

Q: I'm getting ready to build a single story work shop but my lot is far from level to build, so I will need to back-fill in some areas 9'-10'. How do I compact it so in a few years there's not an air space between the foundation and the ground with earth settlement...and will tree stumps grow after being buried?

A: Don't use tree stumps in your backfill.  They don't grow but they do rot.  This will cause differential settling in the future. To back fill properly you must bring everything down to the lowest level and then replace with clean fill in three foot lifts, compacting thoroughly between each lift. (a "lift" is a layer of fill).

Q: I have an unfinished crawl space under one end of my home in southern NY State. Ceiling height varies from about 4.5 ' minimum to about 7'. It has a dirt floor with a couple of large rocks just breaking through the surface, too large I believe to consider moving. Dampness is not a major problem. There is one normal sized exterior door and one small window for ventilation.

I am currently installing PEX tubing between the floor joists to provide supplemental heat to the room above and when this is finished I will install bats of insulation between the joists to make sure all of the heat goes up to the room above. My question is what to do about the floor to eliminate any moisture coming through the soil. The room has great storage space for all sorts of gardening equipment so I need a fairly substantial walking surface, even though it will remain somewhat uneven.

A: (Kelly) One method of damp-proofing a crawlspace floor is to simply cover it with polyethylene plastic, sealing the edges as best you can...and this might be a solution for you. On the other hand, if dampness is not really a problem down there, then maybe you don't need to do anything other than make sure that stored items that are sensitive to moisture are not placed directly on the ground. Since the space is vented to some extent, and it will likely be somewhat warmer in the space with your hydronic heating system, this may do just fine. More substantial solutions would likely involve putting down a moisture barrier and then pouring concrete over this for a solid floor.

Q: Would polyethylene plastic be sturdy enough or sufficiently robust to walk on occasionally and store heavy and medium weight garden tools on? I would expect it to be ideal as a moisture barrier but my concern is durability, not that it would get a lot of traffic, but just bringing things in and out of storage, more frequently during the summer months. I've seen a few floors in crawl spaces covered with a very light concrete product, not even level but just following the contours of the unfinished dirt floor. I don't believe these floors are very thick and I'm not sure how much weight they can bear before cracking or some other failure. Can you tell me more about this product, what it is called and how durable it is.

A: (Kelly) The plastic sheeting comes in a variety of thicknesses, and the heavier duty stuff is pretty tough (at least 6 mil), and it could probably hold up to a fair amount of walking on it. Even if it got torn somewhere, it would still keep most of the moisture from coming up into the room. As for pouring concrete down there, you usually need at least 3" to expect it not to crack, although perhaps 2" would do if you mixed fiber reinforcement with it before pouring. Ordinary concrete is most durable, but a light-weight concrete, made with perlite or vermiculite as aggregate, would also provide a bit of insulation.

Q: I will be building my own home beginning this June after 2 years of research and planning. The last decision I must make is which windows I will be going with. I have narrowed my selection down to either Weathershield wood/aluminum clad OR Marvin wood/aluminum clad, but considering Marvin's fiberglass window. Weathershield now has "Zo-E glass" which has the best U-factor I've been able to find in my price range, plus the best in terms of solar heat gain. However, Marvin's name is very respected. What to do? Wondering if you have any recommendations?

A: To be concise, Weathershield with Zo-E glass is a great value and a great window. Marvin is the trusted name and may give you better service (but that all depends on your sales rep). If it were me, I would go with the Weathershield. I saw them up close at the International Builders Show and thought they were great. I've been wanting to specify them ever since. But, end of the day, you can't go wrong with either.

Q: My question is for John Connell, regarding heat loss and gain. I have used his formula from Homing Instinct to calculate the heat loss, but haven't been able to continue with the heat gain. I have looked for other sources, but most are through purchased software, and are limited to conventional heating options- not taking into account passive, solar, wood stove, etc....so, I'd like to ask him for the calculation for heat gain.

A: Actually, the heat GAIN calculation is a great deal more involved than the heat loss.  That's part of the reason I left it out of the book.  Also, when the book was written we had no idea Global Climate Change was going to arrive over night! Anyway, the best approach for you, I'd say, would be to contact your preferred AC contractor and ask them to help.  They have several good rules of thumb that will get you close enough to price different systems.  Usually they will provide this service for free in hopes of getting the work.   If you want something more accurate, I'm afraid you will not only need the calculations but several very expensive reference manuals.  It might almost be cheaper to hire a consulting engineer.

Q: I was in the middle of building a three story house including finished basement on acreage when the market crashed, the bank sequentially pulled my loan which was a blessing in disguise as then I lost my job due to the company going out of business. I worked for a commercial structural concrete company and they are the ones that graded, put in the footings and basement walls. That is all that was completed and I now need a place to live. After racking my brain to either finish out a small cabin on the land or finishing the walkout basement and making that my home I have decided to research the basement home due to many factors such as utilities and septic.

A: This is absolutely the right way to go.

The walls step down which will allow for more window space and there is a bay footing that will be all glass along the front like a little plant room. I am worried with the way the house will face that there will not be enough light so I thought I could do a row of rectangular windows all along the highest walls that face south, west and north.

That's a good idea. Properly done, a 4' or even a 3' window wall around the top of the foundation could add an enormous amount of light and ventilation.

Could I build a nearly flat metal with brushed sand roof that I could use for a deck top roof? What would that require?

There are many ways to roof and deck your home but much depends on the configuration of the foundation walls and their relationship to the surrounding grades.

The opening of the house faces east and the south and west get all the light so that is why I want to run the windows along the top. The concrete walls have been sitting for a while and the required attachments for framing are not there. Can you advise as to how this could be done?

Many attachment technologies exist: RamSet, Epoxy hold-downs, etc.

Also, the french drain has been sitting there with slack and not tied off for nearly three years, will that be a problem?

No, simply run a garden hose to it to flush out any rodents or sediment that may have built up.

In addition, I when I pour the concrete slab I wanted to stamp it and glaze for all of the floors.

No worries.

Would all this be possible and would it still be underground by being nearly surrounded by dirt on three sides?

Oh yes. You will have a well insulated and very quiet home if it's done right.

Q: I'm coming off of 6 months of living without housing, and I'm still trying to find any mobile home or modular or pre-fab manufacturers that build without toxic materials. Have you come across anything yet?

A: Loads of manufacturers are building green and even LEED but I've yet to hear of one that builds 100% non-toxic. Quite a challenge. Stay tuned!

Q: We have a query concerning use of a vapour barrier? We have a conventional stick frame house built approx. 1950 which has been renovated with some green practices. There are several exterior walls which have had to be rebuilt. All the original siding has been removed and is currently covered with with 2 layers of 60 minute building paper and vertical lathe. The plan is to use natural lime stucco/plaster next Spring when it is warmer. For the interior which has conventional cavity walls, there is pink R20 insulation currently covered with donna conna. We want to use natural clay plaster for the inside walls. Currently there is NO plastic vapour barrier in place. Would you agree with this direction? Or would you advise that a vapour barrier be installed?

A: Your approach on the exterior walls seems sound. The interior walls, covered only with donna conna, would work better if you had some sort of moisture barrier to prevent the donna conna from sucking all the moisture out of your interior clay plaster mix. This could be as simple as a good coat of primer paint. The moisture barrier goes on before the plaster to prevent the transmission of moisture from the plaster to the absorptive donna conna. If this transfer is not prevented the clay mixture will dry out prematurely with unpredictable results.

Q: I would like to add a pitched roof to an older cinder block home. It was built back in the late 40's with a flat roof. The roof has constructed wooden beams. I'm curious what options there are to secure a top plate? What are your thoughts about building a separate support structure?

A: Without a sketch of the wall assembly it's hard to suggest the best way to attach the new roof, but a separate support structure certainly takes all the guesswork out of it.

Q: I have a wood framed, pier & beam home that is covered on the outside with painted wafer board. It will be bricked within the next 2 weeks. I would like to brush on some type of natural, mold resistant paste before the brick is put up. I have a few things in mind but don't know if they will damage the wood over time from humidity. I would like to apply something like salt, borax, or lime. Would these be safe for my health and would they damage the wafer board? Most of the contractors I've asked about this suggest paints or plastic wraps, or they think I'm crazy. I live in Oklahoma so we have a lot of humidity sometimes.

A: I don't think you're crazy but what you're trying to do is sending off alarms. That's why the other builders are reluctant to endorse a natural building solution.

First, seal the wafer board: You can use any kind of primer or poly but you need to seal the wafer board somehow - it's a sponge! There are many non-toxic and even organic sealers on the market. They are expensive but some are less than others. Alternatively, use a good latex based primer WITH a FUNGICIDE additive. There are many products to choose from and some are completely green. When you seal the wafer board, make sure to do it on BOTH sides or it will warp.

Second, design Your Wall Assembly: Will the bricks be right up against the wafer board or will there be an air space? If there's to be an air space, you'd better supervise the bricklaying closely to insure that it doesn't get clogged with spilled mortar (very common). With this approach you need a screened vent top and bottom so the air can move through and take out any moisture that migrates into the wall.

Or, if the bricks are to be right tight up against the wafer board, you will want to wrap the wall with a drainage product that can wick any moisture out of the wall. This is where most builders (myself included) let the green metric slide a little in favor of a more durable solution. Let's face it; if you build an all-natural green house and it rots out in 20 years that's not very sustainable, green or resource efficient.

If you insist on using a natural building material, I believe the use of "light clay" will work best. You will still need to seal the wafer board. Then you can attach a metal lath with staples. The light clay can be applied like stucco to the lath. If you're super worried about mold, then mix some borax into the light clay.

Moisture and mold are not to be taken lightly and if this house is any bigger than you can afford to lose, I'd delay the brick work until you are absolutely positive you have a sustainable solution. Fools rush in…..and all that.

Q: What style of green home construction do you think is best suited for Northern Minnesota? I am not sold on the "tight" home construction methods.

A: I’m in northern Vermont and over the years I have become a big advocate of the factory built, custom green home. That’s pretty much all I do anymore and I’m still able to match the design to the land, super-insulate, incorporate salvaged and recycled building materials, etc. It’s a great way to go but it’s also a very tight house. ERVs and HRVs are standard as are HERS ratings and blower door tests. If you just want to keep the snow off, then I’d suggest a nice log home. It’s like building with “cracks”; plenty of fresh air.

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Established in 2001, GreenHomeBuilding.com is primarily a labor of love. Kelly, and the GreenHomeBuilding team of experts, have answered thousands of questions for readers over the years, and we continue to publish up-to-date information about increasingly important sustainable architecture. If you feel moved to assist us in this work, your kind donation would be much appreciated; this can be easily done through our PayPal account:
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I specifically disclaim any warranty, either expressed or implied, concerning the information on these pages. Neither I nor any of the advisor/consultants associated with this site will have liability for loss, damage, or injury, resulting from the use of any information found on this, or any other page at this site. Kelly Hart, Hartworks LLC.