Homestead Green Building: Roofs

Roofs are probably one of the last things you think about when you start planning your homestead, right?  You may think standard style roofing trusses or whatnot.  Maybe you just think in terms of what you're going to need in order to place solar panels on top.  There is, however, a lot to consider, and it needs to be done while, or maybe even before, you decide what the general building style and materials of your home is going to be.  You must consider how large of a space you are covering, if it's going to work like a standard roof, if you want something simple where it's bare minimum with beams showing on the interior, if you want an attic large enough to maybe eventually turn it into an extra room, etc.  The good news is that there are options for a green roof that are not only beautiful, but also relatively simple to build.  Well, simple so long as a few - rather important - considerations are taken into account.  So let's take a look at some options - and a lot of pictures.

The simplest design would be a dome roof.  Dome? Simple?  Actually, yes!  Very much so! Most of the building styles we've looked at can easily be adapted to include a dome roof.  The walls simply continue up, gradually working there way into a smaller and smaller area.  Ideally this is done when the house design, itself, is a round house.  It can be done with other shaped footprints.  It just flows better (personal opinion) with a round home.  Of course, it will take extra considerations in so much as any weatherproofing that should be done to protect a natural material, such as cob or adobe.  The benefits of a dome go beyond just the idea of extending the walls up.  For smaller domes, often times there is no need for extra support.  Larger domes may need rebar or some other form of extra support.  The design of a dome lends itself very nicely to building in areas that may be subject to earthquakes, and even hurricanes.  This design has been used for centuries, showing that it can stand the test of time.

The next roofing idea is a reciprocal roof.  If you are unfamiliar with these beauties, I highly suggest you get familiar.  They are beautiful.  In fact, they can be absolutely stunning!  The idea, again building on a round house, is that timbers are stretched from the exterior walls to the middle of the space where they interlock with each other.  It can consist of as little as three timbers, to pretty much as many as you want to have.  It is self supporting, and surprisingly strong.  A center support is not needed, although there are some who would encourage it for a larger space.  A reciprocal roof can span as small or as large of an area as you need, assuming you can find timbers the length you need.  You can even build a double reciprocal design.  When done right, any weight on top of the roof pushes down, causing the timbers to press into each other as opposed to pushing out towards the walls.  These timbers are left visible on the interior, creating a simple, rustic, and amazing design.  What goes on top of this frame is up to you.  While you could cover it with standard tiles or shingles, it can also bear the weight of a green, or living roof.

A living roof is pretty much exactly what it sounds like: it's a roof made of grass or some other living plants.  A simple design: waterproofing, drainage, soil and plants.  This option is almost a guarantee when choosing an underground or even an earth bermed home.  Now, there are some very serious considerations with this one.  The soil and whatever you choose to use in your living roof is going to vary depending on where you are.  Because of that, there is no standard in determining weight load. This is vital to the overall structure of your home.  Too much weight sitting on top of a wall that isn't properly supported will lead to disaster.  With properly built walls, the next thing to consider is what is going beneath the soil and plants in terms of support across the expanse of the roof.  This is where a reciprocal roof becomes a great idea.  Since they can support heavy loads, they are ideal for heavier mediums used in green roofs.  Another thing to consider with a green roof are dead loads and live loads.  Dead loads would include the medium, plants, and snow loads (where applicable).  Live loads would include people and/or animals that may walk across the roof.  All of these things must be taken into consideration when figuring overall weight load.  You also have to consider, and properly plan for adequate drainage.  While the soil or other medium will absorb a certain amount, it's crucial to completely seal up the roof so that no excess water finds it's way into your home. For waterproofing, the most commonly suggested material will be the same waterproofing material that would be used with a standard roof, along with an extra layer of poly laid on top.  Here, however, is a design that uses birch bark for waterproofing in a church built more than 130 years ago.

So there are three green options for your homestead roof.  Of course, there are a number of other roofing options out there, including traditional standard roofing.  These, however, are what I would consider the best green options.  As with anything else, do some research and find what works best for you and your homestead.  Please remember that I am in no way an expert or professional.  I am merely here to provide a starting line for you to leap off of for ideas.  I will be taking next week off for Christmas, but I will return after New Year.  Here are a few places to do a little more reading on the roofs I've covered here.

Dome Roofs

http://ilovecob.com/archive/the-dome

https://www.intelligentliving.co/building-earthen-dome-homes-6-weeks-diy/

http://www.earthbagbuilding.com/faqs/domes.htm

http://www.earthbagbuilding.com/plans/envirodome.htm

Reciprocal Roofs

http://greenbuildingelements.com/2008/10/01/the-reciprocal-roof-beauty-strength-and-simplicity-in-a-roof-frame/

http://www.thatroundhouse.info/reciframes.htm

http://www.theyearofmud.com/2008/11/26/how-to-build-a-reciprocal-roof-frame/

http://www.naturalbuildingblog.com/reciprocal-roofs/

Living Roofs

https://www.gsa.gov/portal/mediaId/167831/fileName/Challenges_to_Green_Roof_Construction.action

http://straw-bale.blogspot.com/

http://www.livingroofsinc.com/

Homestead Green Building: Foundations

A house is only as good as it's foundation.  You've heard that before, right?  Well, it's true.  When it comes to green building, there's really not a whole of information out there (at least not that I've found) on building a green foundation.  Even within a vast majority of green building resources, a concrete foundation seems to be quite common, and even highly suggested.  It's by no means the only route to go, though.

As we've seen in looking at some of the different building styles, there is something at the base that is called a rubble trench.  This allows you to build with a natural material, and yet keep it off the ground so as to help it last longer - much much longer.  A rubble trench is considered a foundation.  It is a foundation upon which you will build your walls.  The technique has been around for a very long time, but it wasn't until architect Frank Lloyd Wright began using it that it started to regain popularity.  Even today, a lot of code enforcement doesn't include rubble trenches.  So you may have to do a little research, and maybe a lot of educating, in order to get your rubble trench approved.  I haven't gotten into it too much before, so here's the basics of a rubble trench foundation.  This will be the overall outline of your home; where the walls will sit.  You can do it by hand, but a small backhoe is not a bad idea.  Dig a trench where you want the exterior walls to be.  This trench should be a minimum of 16 - 24 inches wide, and go down to a few inches beneath the frost line.  Dig the trench so that there is a slight slope going downhill and away from the house.  This will help with drainage, keeping moisture away from your home.  Once the trench has been dug, now you need to fill it.  Tamp it down.  A good hand tamper will work nicely.  Start with a breathable layer of wicking material.  This will aid in the drainage, and also keep the rest of your foundation walls from settling too much.  Now starts the "rubble".  Use rocks, stones, recycled concrete, or something similar.  Each piece should be 1 1/2 to 3 inches big.  Fill the trench up about 4 inches.  This should be at or slightly below the frost line.  Now lay a pipe.  This pipe should be roughly 4 inches diameter with holes drilled all around at regular intervals.  Yes, this is another step to help with drainage.  Once the pipe has been laid, fill the trench the rest of the way up to grade level.  Don't forgt to tamp every vertical foot or so.  This is where you'll begin your stem wall and then whatever building material you choose on top of that.  It's simple, it's effective, and it's natural.  It is a lot of work, but it's worth it.

So that's a good foundation for the walls.  Now what about the rest of the house.  What do you do beneath the floors?  That's where it can get as simple or as complex as you want.  If you really want to go rustic, you can simply have dirt floors.  Or, you can always go the route of building your home on stilts.  That's an entirely different set of circumstances that I'm not going to get into here.  For a home that sits on the ground, assuming you don't want a dirt floor, there are some things that hold true no matter how you proceed next.  No matter what else you decide to do, you must have a moisture barrier, as well as a radon barrier.  Radon is a gas that is naturally released from the ground, and it is toxic.  Personally, I would think it's a horrible mistake to not put in a radon barrier.  Yes, this and the moisture barrier will most likely be a form of plastic.  I regret to inform you that it is currently the best thing out there to provide an adequate barrier.  I will update this post if I find a natural alternative.  Now, when it comes to barriers, make sure to know the difference between a moisture barrier and a vapor barrier.  They are not the same thing.  Utilized improperly, and you may inadvertently trap moisture where you don't want it.  Consult a professional for any questions you may have.  Beyond those two things, insulation is the next consideration.  This is not a requirement everywhere.  But again. I think it's something that should not be skipped.  There are natural insulation alternatives.  Here are a few options.  While primarily used in walls and ceilings, it can also be adapted to floors.  It all depends on what you're planning to use as your actual flooring material.  Personally, I think my favorite flooring idea comes from here.  A layer of volcanic rock is used for the insulation.  The author here goes through all the steps of making his floor, even including tubing for a radiant heat system.  And then lastly, is his earthen floor.  I'll get into earthen floors (and a lot more) in a later post.  But this is a good system.  Now he states that there is not a lot of R value in his floor, but it's ok for him because of the nature of the building he's constructing.  More could definitely be added for a home floor.

So there you have it.  It's pretty basic.  Always remember that there may be certain code requirements for residential buildings.  Please check and make sure that you are well informed.  It always helps the process go smoother if you are aware of information that code enforcement may not be.  You may need to - politely - educate them.  When in doubt, always consult a professional.  Here are some links with further information on foundations.

http://thehtrc.com/2010/building-green-homes-footings-foundations

http://www.homeadvisor.com/article.show.Going-Green-Foundations-Retaining-Walls-and-Waterproofing.16451.html

http://www.ecobuildingpulse.com/news/part-6-foundation_o

http://www.diynetwork.com/how-to/maintenance-and-repair/sustainability/the-basics-of-eco-house-construction

https://greenbuildingsolutions.org/green-building-materials/foundations/

https://www.buildinggreen.com/blog/choosing-foundation-materials-subconscious-decision

http://www.buildnaturally.com/EDucate/Articles/RubbleTrench.htm

Break Week

I am taking a break this week in order to focus my attention on helping my son study for semester final exams.  I thank you for your patience and understanding.  I will be back next week with information on green foundations.  Have a good week everyone!