cheap floor

[marty van diest]

I'm thinking of building a small log cabin and trying to keep the costs as low as possible.

Can anyone forsee the problems with this system.

The overburden cleared of topsoil down to well drained gravel. (there is less than a foot of topsoil here).  Then the hole filled with gravel back to a few inches above the surrounding ground level.

On top the gravel will be a 4X6 treated timber.  Then the log walls directly on top of that...that's the foundation.

For the interior floor there will be two inches of sand, 6 mil poly and then 2" blue board.  Right on top the blue board will be carpet.  

Do you think I need a layer of wood and do you think I will have moisture problems?

[glenn kangiser]

Mike Oehler used a similar method in his earth carpet floor system, however he just graded and tamped the soil then put the plastic and carpet over that.  I assume you will be above any surface water that could come in through the gravel -as you said it was well drained.  It seems to me that you may want a layer of plastic or drainage netting over the gravel as the sand will settle to the bottom of the gravel especially when dry.  

Not conventional, but I am using cob and cement stabilized adobe floors - They work.

The light duty concrete floor from India mentioned by Ken Kern, with the plunger posts is also durable and cheap to make - one inch thick concrete over hessian or burlap.

http://www.countryplans.com/bbs/messages/7258.html

[marty van diest]

That is very intriguing Glenn.  I really would rather have concrete because of the fire safety.  This is going to be heated with wood.  

I thought about just using pavers but they are kind of expensive.  

I really like this light duty concrete idea.  How is yours holding up?

[glenn kangiser]

No problems - I used it in about a 10x12 bathroom.  There is a short crack where it transitions from fill to solid rocks - which had to be left there, but that is to be expected.  Concrete will crack where it wants many times anyway - the reinforcement takes care of that.

I used erosion control netting - 1"x1" woven jute twine comes in a 4' wide roll 400 feet long for about $70 available at nursery supply stores, feed stores sometimes and Home Depot etc.

[Amanda_931]

Glenn likes soil cement.  

Some people just put a sand/clay/straw (or woodchips or sawdust) mix down over well-tamped gravel, pound it in really well, level it--can be troweled like concrete, the clay comes to the surface), finish with linseed oil (mixed either for the first or last coat with mineral spirits or that very expensive but much greener stuff from that guy on Rufina Circle in Albuquerque.

This month's project is to finish the floor, to replace to boards we were supposed to screed up against with a dark colored mix.  It's not going to be as wonderful as I'd hoped, but.....

[glenn kangiser]

That's right , Amanda.  About a 30% clay 70% sand mix with a few handfuls of chainsaw cut straw per 10 shovels of the above mix.  Sand calculation must include any aggregate in the clay also.  The clay must be mineral clay - usually a few feet under the top soil.  Not organic clays from near the surface.  Not all clays work as well as mine.  Experiment.

Concrete added at about 7% to 10% will stabilize the mud but the linseed oil will not penetrate as well so we like the plain mud better - it will shrink and crack so let it then grout the cracks in a few weeks then put on about 4 layers of linseed oil -I like to thin the first coats about 50% with paint thinner.  Shelley also mentioned dissolving Styrofoam in Lacquer thinner and using that on walls of cob (same mix as above built in place).  I haven't tried that one yet but will some day.

About 4 to 30% Henry's #107 asphalt emulsion can be mixed with the above mixes along with some cellulose or aged sawdust to make a floor surface that is waterproof also.  Taylor Publishing has information on this mix.  It was also mentioned by Ken Kern.

[Amanda_931]

Samples are necessary, the larger the better, I'm told (who, me, do everything I'm told?  Hey, I left the sample out in the rain all winter and it still looked good).

What you have--I had to buy, paid for trucking only, the local gravel quarry had scooped clay off the next place they wanted to get limestone--is going to vary in how much clay there is in it.

I used 3 sand, 1 clay and I think 1 wood shavings.  And it got rolled around in a tarp, and stomped!

The places that cracked sounded hollow, and cracked when they were walked on.  I fixed them.

It will look better longer if you take your shoes off at the door.

[marty van diest]

The clay/cobb floor sounds good.  But I'm not sure where I'll find clay around here.  I'll have to explore a little.

How thick do you make it?  About 4 inches like concrete?

And doesn't the straw stick up and leave a scratchy surface?

[Amanda_931]

Mine was inch and a quarter over 6" or so of  well tamped gravel.   I was on a kneeler pad with a rubber mallet in my hand for the edges. I think Becky Bee thinks 3/4 inch is OK for the clay/sand/sawdust (wood chips, chopped straw) mixture.

The Steen's book on earthen floors recommends fairly thick floors, although I understand that they are doing them in a lot simpler fashion than what was advised their  older booklet on floors--may have a new one out by now.

Chopped straw, wood chips, sawdust are all about as likely to stick up as the gravel in finished concrete.  for the same reason.

(If there was pottery in prehistoric times where you live, you've got clay, if you're lucky, right below your topsoil)

Finish with boiled linseed oil, "danish oil" tung oil.  Linseed's the cheapest.  Maybe the most likely to cause spontaneous combustion in rags and grubby tee shirts.

It's generally recommended that you put something that wears well in doorways and other traffic areas.  Jury's still out on my choice, those "faux iron" decorative or utilitarian rubber mats.  Tile--ceramic, glass, wood, for instance.  And shoes left at the door is a great idea.