Earthen floor outside

I am in the planning stages of creating a studio under my deck. Currently the deck is treated 5/4 lumber decking, 2x8 treated joists on 16",and no roof. My idea is to cover the deck with clear panels, build up solid half walls, and then use a natural material sealed with linseed oil, on top of a membrane of some kind. The 5/4 will be removed and repurposed, and plywood will be layed down. I have never worked with a natural floor before, but I love the idea. Concrete came to mind first, but if I can do it with something better I will. Any feed back would be appreciated:)

Blayne Prowse wrote:I am in the planning stages of creating a studio under my deck. Currently the deck is treated 5/4 lumber decking, 2x8 treated joists on 16",and no roof. My idea is to cover the deck with clear panels, build up solid half walls, and then use a natural material sealed with linseed oil, on top of a membrane of some kind.

Hi Blayne,

This should work fine, but earthen floors outdoors are tricky. Lime based concrete floors will be less maintenance and are much stronger, but for most, laying stone will be the best bet outdoors. This is and showers are the only places that I still use OPC. Others on here may have better alternatives, but I use modified thin set to secure Kerdi membrane to solid 1x planks or 3/4" cdx at minimum. Then set flagstone, tile or lime based concrete on that.

Good Luck,
Bill

Thanks Bill.

I was chatting with another fellow and the topic of light weight concrete came up. This could be another option. I am leaning towards tiling the space(10x15), but the light weight concrete has some appeal. It is tough to find information about waterproofing a deck with out using fiberglass or vinyl:(

Hi Blayne,

We have strayed from natural building already, but lightweight concrete is not a product that I would ever use. I don't like the plasticy look of it and there are a lot of additives. Natural tile like saltillo can give a lot of the benefits of an earthen floor without the danger of cracks resulting in a water leak into the area below. Tile is much easier to set than flagstone as well.

All Blessings,
Bill

Hello Blayne,

I haven't commented because I don't believe I have a very good mental picture of what is trying to be achieved??

Some photos would really assist in understanding the goals.

As for earth floors, there are countless recipes (some good...some not so good reinventions.)

Here is one form with a very long and well proven track record going back perhaps over a thousand years....三和土 (Tataki)

Good luck,

j

Sure I realized that I wasn't being very clear. I will try to post some pictures by the weekend:)

Here are some pictures to hopefully clear up my idea for you all. The deck is now open and I hope to close it in to act as a roof over the slab underneath, which will become my workspace. I am going to add a roof over the existing deck to help shed water and protect whatever material works best. I am open to suggestions.







I will be stick framing in the workspace and finishing the walls with cedar most likely. I hope to have the deck 100% waterproof. I don't mind doing a yearly maintenance on it(re-sealing with oil etc).

Gosh...I did an "Oh Boy!" and then a Hmmmm....and still can't wrap my head around the current path as being either plausible or functionally achievable as intended...sorry...

I am not just "shooting this down," either. I have seen this tried several times over the years, and it has never worked, or worked of for very long and it has always been messy. Many end up trying to do something like what is done on roof tops of skyscrapers and other flat roofed commercial or large structures. These are "double" and "triple" roof systems, all employ some really nasty materials and all are big business in cities. It is a good business too, as none of the systems last more than perhaps 20 to 30 years (most much less) at best before failures start, and need repare.

Now on a more positive note...I can talk you through a few I (et al) have pulled off that will work...

This leaves the deck just the way it is. If...(and it would seem you do...have enough "head room," a secondary framing under the dect has to be created to "shed water" away from the structure and the space underneath. In your case, I would probably shed towards the left side of the deck as you face it from the yard, and away from the primary entrance of where the wood now is brought in on the right side. If this method appeals to you, I can go into more detail and talk you through it. You are basically building a shed that will fit underneath the deck. It can use some of the current framing or be its own independent structure. I recommend the later one over the first...

Regards,

j

Thanks Jay. I certainly did not have my heart set on any one way, and just thought I would investigate the possibility of the floor idea. I will now pursue building a metal roof under the deck and framing in my walls. The space is only 150 sq feet, so I would prefer to infill rather than build a free standing structure. My main concern for using a conventional roof was how to connect it to the house and how to fasten the roof to the house. Now I will remove the siding so I can fasten a header to the house, and lift deck boards to access fastening points for the roofing. I am a handy guy having worked in trades for most of my working life, but all of it is in sheetmetal and heating, not framing. Any tips or suggestions, reading material would be appreciated:)

Any tips or suggestions, reading material would be appreciated...

Hi Blayne,

Before I share my next thoughts on how to proceed...may I ask if you own this home and/or may move at anytime perhaps in the next ten years? This "may" have influence on what I am thinking of suggesting...

Regards,

j

I own the home and we intend on staying for quite sometime. Even if we move we intend on keeping it as a rental property. More usable space is always good.

Hi Blayne,

That's what I needed to know....

It hasn't really change my first thought on this project. From past experiences with "projects under decks," it isn't a matter of..."if"....but when things either have to get "torn out" or redone, because the entire complex becomes to "monolithic" in form. Decks by their very nature are "transit architecture" in the sense that they slowly decay...especially modern deck designs and methods of construction. Avoiding this in the design is paramount to long term function and not having to "undo" good work. With that said, the new structure can be attached to the existing frame of the house, or be built as it own structure on "skid sills" and rolled under the deck. In either case, I would not recommend making any part of the "new work" become part of the framing of the deck as it now is.

Now, in some areas, attaching anything to the superstructure of an existing house can "raise eyebrows" by local building officials and/or tax officials. Even sheds in some areas are inspected and/or taxed. So know this before hand to avoid issues down the line.

Being a Timberwright and natura builder by disposition, I would go for a design and build of a simple timber framed "pent roof shed" on to primary sill skids and roll the entire structure under the deck as it now is. The deck looks to be in the area of 4.8 m x 3 m (~16'x10') so your shed will have to be slightly smaller than this.

I would also share a little trick I have suggest to folks over the years that are active and accomplished DIYers. If they want a little "cottage industry" and save on paying taxes on a shed or workshop but also have a "heavy handed" tax authority, what they can try as soon as the structure is done, would be to put it up for sale. If a structure is part of a "small cottage industry" that a DIYer does on the side and is actively selling it can not be taxed in many areas, and in some areas it may not even fall under "code inspector authority." For example the "management and sales" office buildings at modular and trailer home sales lots across the country are in both active use as "offices" and active "sales" as a product commodity...they can't be taxed (currently in most areas) as a "fixed asset." Pricing has to be reasonable, but doesn't have to be inexpensive by any means. I have never known one of this sheds or cottages to sell for less that $1500/m2 (~$150/ft2). Just a possible...FYI worth thinking about.

Another very positive thing about timber framing modalities is that the shed can be built and rolled in or designed to be built in place. Either way they are very modular and can come apart just as easily. I have seen entire structures built without any metal hardware...including the roofing!! The reason I suggested the roll in is to aid in facilitating the structure more easily ergonomically and getting to the roof area. Its all food for thought. If your game, download Sketchup, and I can send you a boiler plate plan or you can find one on one of the forums...

Regards,

j

Thanks for your feedback Jay. I agree that decks are a fragile part of a house that fall apart faster than most anything on a home, aside from maybe asphalt roofing(grrrrr that stuff makes me angry) Weighing your thoughts, and my visualizations of the build and my wishes for the space, I will construct this like a shed add on to the house. A shed style roof built up to the posts, but not including them into the build. I really want a concrete floor so I can play with a RMH in there, and to leave the most amount of usable space for my woodworking hobbies(bowyering). As I progress I am sure there will be more questions I will pose to you:)

Genius, jay. You never cease to amaze me. The shed bussiness is by far one of the best ideas i have ever heard. One could build a series of cabins for guests and woofers/hands. And claim a horrible sales record of their cabin bussiness. If i could give apples, this would be where.

Hi Chad,

Thanks for the kind words...there appreciated..

I know a number of folks using this now (they shall remain nameless to avoid attraction) but as long as the "pricing" is ridiculous and the architecture is clearly "removable" within its contextual design...like timber frames are...then these become both a "use asset" and a "sellable commodity" all at once. I have worked up a number of design formats on simple stone foundations, and these can actually get pretty large...7 m x 7 m (~24'x24') as still stay within the range of quick to disassemble and move. If a person had the space one could make even a small show model as office space and have "cross sectional views" of the wall systems with insulation and electrical/mechanical displayed which would further bolster the fact that these structures are meant for sale...I would be pleased to see folks take this idea and make it work for them...as it has for others...

Regards,

j

Hello Kadly,

Welcome to Permies...

I am not sure I know of any, "local home expert," in the mainstream building fields that have very much expertise in "traditional/natural" building systems. I would also suggest that referring to these as "the right way," of building would be a real stretch of a subjective perspective compared to the many systems of building shared here on Permies from Timber Frame to Cob structures...

I also do not think that the company "wholetiles" should be promoted here as applicable to the "earthen floors," forum...

Regards,

j

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