teeny log cabin. Foundations?

[charlieb]

It should really be in the bodges section, but here we go.  I've moved back to Scotland so brain is in build-pointless-things mode again, and there are lots of trees down on the farm at home.  So I'm planning to build a little log cabin: probably six foot by eight foot internal dimensions - basically a tiny sitting/cooking space with a stove, and a bed on a head-high platform at the far end from the door. The concept was inspired by fisherman's huts in Sweden (I spent some of the summer walking round  an island next to Gotland) which have the same internal layout. Original plan was to build a basic frame using bandsawed rough timber sized around standard insulation sheets,  but my tree-surgeon flatmate has persuaded me to give log-cabin construction a go.  This I can do myself with my chainsaw mill (google 'alaskan mill') and it can use timber in-situ without ever leaving the forest where the cabin will be.

So, my question is about the foundation/base.   My thinking now is to just take one edge off two bigish larch (durable in the ground) and dig them carefully into position maybe 1/3 submerged as two paralel 'skids', carefully levelled,  roughly 8 feet apart. This provides a nice level base to then build the log cabin, and a rough plank floor, onto, and would also provide space under the cabin for insulation (I have a vague idea that the cabin could be used as a sauna instead of/as well as a bothy, although that would depend to some extent on the degree of heat loss through the walls).    Anyway... does anyone have any thoughts on whether this idea would provide a reasonably stable base  for a reasonably long time? Or is there something simple I can do by hand (I don't want even to hire a minidigger) to improve the durability/stability - maybe digging trenches to put the edged trees in that are part-filled with rocks? Or something like that. Basically, if there's something simple I can do I want to consider it now before it's too late and I curse myself when the thing falls down in two years time.    As always, any thoughts at all are welcome. Thanks
Charlie

[Heinz]

I'd have thought you'd want to keep the logs off the ground? How about some big stones/small boulders for the foundation with the first log on top of that? A few inches off the ground is going to make it last a lot longer..  You could just use a few big stones to do the supporting and drystone (with turf 'mortar' in the gaps) the spaces in between.
Got an instruction thing for log cabin building here on CD somewhere, could post you a copy if you like?

Heinz

[biff]

hi charlie,
          if you are going to get busy building a little log cabin then may i suggest that you use a chasis of an artic trailer shortened to about 12 ft this would just include the wheels at the rear and chopped off with a drawbar fitted.these old trailers are cheap as chips toward their end of life and as long as the chasis is in good condition a coat of paint will suffice.
        you could extend your sloaks(flooring joists) to 9ft and build your log cabin up to 8ft high if necessary,bringing the sides down past the wheels to the ground, no one need know that it is on wheels,the drawbar can be detached and reversed to store underneath. your heavy duty forklift batts will also store in there, the great thing about this idea is that if you decide to run away from home you can tow your log cabin after you with a big tractor,
                  its just an idea.
                                    biff

[AlanM]

Hi charlie,
would advise you to build off the ground, rather than digging in the first round. You could lay a course of blocks onto a found of hardcore with the logs starting on the blocks. No dpc between the logs and the blocks, bed them on lime mortar. Alternatively, some large boulders placed at the corners with the first course spanning between them, the floor would then be between first and second course.
As for construction i would advise scribe fit rather than milling flats, it will be difficult to maintain a seal with flats as the logs will move, particularly those with spiral grain.

Alan

(I should point out that I am a log builder, feel free to ask anything else)

[billi]

Hi

Our 60 foot by 20 foot  cabin sits on concrete blocks  as well
I choose them cause water penetrates through and the keeps the under-construction timber  dry
We used a lot of linseed oil as well treating al the wood

If your ground is relatively flat ,  i would dig out by hand  , compact the ground ,  put down a membrane  and then  "hardcore"   and place the blocks

If the ground is uneven or on a slope , i would dig in stilts  ,  like those corrugated plastic  black ground pipes   upright and fill with concrete or even hardcore only  ....

Billi

[JohnS]

I put some decking in my garden 12 years ago.  I could not be bothered to dig holes, put in posts and concrete, level, add joists etc before laying the decking.  Instead, I bought some secondhand railway sleepers, positioned them on the ground, scraping away a bit of soil or stone where necessary so that they sat level (slight slope for drainage actually), laid and nailed fence posts on them as joists (on the basis that fence posts have lots of preservative traetment) and laid the decking on top.

It is still rock solid and steady and as good as the day it was built.

So there is merit in Charlie's idea and I would not dismiss it out of hand.

John

[dhaslam]

Make sure the floor is mouse proof.  Something like fine  netting wire underneath perhaps?

[biff]

or rat proof,
          ugggg, i had a visit from mr rat just before those bad storms began,he bored a hole up through the floor of my workshop and began helping himself to the dogfood.luckily enough i spotted it in time,blocked the hole,removed the dogfood and fed him nice little blue blocks which he gobbled up quickly.
 i left him a nice supply of water but it took over a week before he surrendered.i found him stiff behind the door one morning and sent him on his way.
   rats are intelligent creatures and are one of the few mamals that use mood transmission,like bees  or ants do. they are carriers of deadly diseases and should be kept well away from livestock and living quarters.they also have family systems like wolves do but unlike wolved their combined feelings will dictate their actions,fight or flight.old lorenze was in awe of them and that says something.
                                                                                                     biff

[M]

I used to have pet rats, they are lovely interactive animals, when bought as domestic pets. But the wild ones, boy, some of the guys 'little Mo' our, found when feral, pet cat has left for us under the coffee table, are quite impressive.

Anybody fancy one of these in there bins

http://www.jdjournal.com/2012/01/09/bronx-foot-locker-boasts-giant-rat/

The mouse net is a good idea. last time I lost mine I couldn't do any banking or check e-mails for a week.

M.

[biff]

a large breed of rat estabilished itself on the banks of the mulroy near the old mulroy bakery.the story goes, that the polish boat that supplied the flour to the bakery brought these large fellows to our shore. then the esb went into fishfarming and the residue from the fishmeal seems to breath life into these monsters.when i was building my house overlooking the fishfarm in the late 70s i decided to trap these rats and see what they were like.
    my first attempt brought 5 very big ones into the one cage,they were black or brown with very long incisors,extremely vicious. the new house build was about a mile as the crow flies from the shore.the new house was in a pastoral/coastal setting with no buildings or any other source of food yet these rats kept on coming for a good 3 weeks before they slacked off and stayed away.
   the word got around as to the size of these rats.the locals were not aware there was a problem but within a weeks i had several people filming these trapped rats,unfortunatly there was no utube in those days.they say that fishfarm rats are always a lot bigger than the norm but that is only hearsay.it is more likely that the breed did actually come in from poland.i always kept the traps active but never had a problem after that.
                                                                                                                biff

[offthegridandy]

Leaving the rats to one side,

An alternative for footings and to keep the timber of the ground would be to cast 6 concrete plinths or pads.  Depth into the ground would be dependant on local ground conditions.  I recently built a new garage/workshop approx 24ft X 16ft.  I put conc pads at each corner then 4 ft apart around perimeter, Then dpc then hollow conc block on each pad.  Then sole plate level across blocks.  Vertical oak posts approx 8inch x 8 inch  tennoned through sole plate and into hollow block. Rest of construction was standard timber frame construction.Solid as a rock and absolute minimum of digging. Mmmmm me hates digging.

Andy

[stephendv]

There are also some more responses on the greenbuildingforum: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8170

For our 12m x 4m cabin I eventually resorted to using a digger with auger and those sonotubes that billi mentioned to cast 10 pillars.  For a small cabin, I'd go for a shallow concrete footing, or even a precast paving block.  Then build pillars out of wood off that.

[charlieb]

Many thanks all. My problem is to  balance a) evident sense in doing it 'properly' (ie using concrete/dpc/hardcore) and b) my desire to do it as simply as possible (the cabin really isn't 'for' anything.  In fact you could say it's only purpose is so I can learn from my mistakes building something unimportant before I build something important later).   Still, as always very useful thoughts from Navitroids.  Thanks.  I'm going to head up there again this weekend and spend some time there to see what's easily doable and what's not.     Alan M, I'll almost certainly get back to you too once I've got beyond thinking about the base and onto the actual structure.