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Log cabin without seasoning logs

Started by Iommi, May 20, 2021, 02:39:37 PM

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Iommi

Hi folks,

I'm falling spruce trees right now, for my log cabin construction. (8-12 inches diameters)

I wanted to debark and stack my logs right away, so my logs can season about a year before building my walls, but I'm really looking forward to start fast.

So I'm wondering, what could happen I start right building right after debarking, without seasoning ? I'm doing scandinavian log method, plus I will pin logs together, top on bottom.

- Moisture between logs ?
- Structural issues ?

Thanks a lot !


DonW

Starting construction directly after felling is the standard procedure with the kind of construction you mention. There are many so called Scandinavian methods so it's not clear which particular method you intend. Will the logs be hewn on the in and outsides? Almost all Scandinavian log buildings are.  Which corner joint, there are many?
The moisture issue you mention is not a concern at all unless you misguidedly try sealing joints with some non-permeable material. Structurally you will have to understand and accommodate for significant shrinkage in the corner joint and anywhere vertical elements interact with horizontals, door jambs, window jambs and so on and so on as well as the roof. 
Hjartum yxa, nothing less than breitbeil/bandhacke combo.

barbender

Too many irons in the fire

Joe Hillmann

Mold will probably be an issue.  But I am drying logs for my cabin and they are molding as well.

barbender

If you are using the Scandinavian full scribe method, the grooves will get mold in them. It doesn't really matter. Even if you season your logs, the moisture content will not come down below what mold can happen at. I am of the firm belief that the best place for logs to season (unless you are in a dry climate) is stacked in a wall, under a roof. Usually, nothing good happens to logs stacked up to season.
Too many irons in the fire

firefighter ontheside

My home is built with Scandinavian scribed red pine with swedish coped corners.  The logs were green when the home was built.  The 10' walls have shrunk about 5" since originally built.  The shrinkage is the biggest thing to worry about.  My builder made his corners with what he called a "shrink to fit" method.  Many similar methods that I looked at before I picked him had corners with huge open notches due to shrinkage.  Mine are very tight after 20 years.  Windows and doors have to be designed to allow for the opening to get shorter.  Everything on a second story have to be designed to allow for it to get lower.  Plumbing has to be flexible.  HVAC has to be flexible.  Any load bearing walls or posts in the interior have to  be designed to be lowered as the home shrinks.  You talk about pinning the logs together.  My walls have full length threaded rod going from top to bottom.  As the logs shrunk I had to keep tightening the nuts in the basement.  All this shrinkage took at least 5 years and that was with conditioned air on the inside.  Trying to dry the logs before using would probably take 10 years.
Woodmizer LT15
Kubota Grand L4200
Stihl 025, MS261 and MS362
2017 F350 Diesel 4WD
Kawasaki Mule 4010
1998 Dodge 3500 Flatbed

DonW

Quote from: firefighter ontheside on May 21, 2021, 08:30:47 AM
.  Trying to dry the logs before using would probably take 10 years.
L
Why, are there no log home kiln driers? :(
Hjartum yxa, nothing less than breitbeil/bandhacke combo.

firefighter ontheside

I think you just invented a new industry.
Woodmizer LT15
Kubota Grand L4200
Stihl 025, MS261 and MS362
2017 F350 Diesel 4WD
Kawasaki Mule 4010
1998 Dodge 3500 Flatbed

doc henderson

they all use solar and wind.   ;)   :D
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

btulloh

HM126

Don P

There's one log home company about 5 miles away that does KD, another about 20 miles away. I've built both ways from multiple companies and much prefer dry. I've bought KD timbers from the company about 20 miles away. I've also built supposedly kd log homes that I can only assume both doors of the kiln were open and the cart never broke stride  ::).

DonW

Hjartum yxa, nothing less than breitbeil/bandhacke combo.

mike_belben

How well does the average whole debarked log behave in a kiln?  Id expect them to blow apart or something. 
Praise The Lord

doc henderson

I was going to joke that I would season my logs with thyme.   :)  Makes you wonder how to get the water out.  hot air pulls from the surface creating a large gradient and physical stress.  heating the whole log could help move water from the center.  I wonder about vacuum.  could build individual vacuum kilns for log if you had cheap pipe painted black and in the sun and pull a vacuum.   :P   :). would have to cycle with outside air to get rid of the released water.  lots of info about drying in place allowing for shrinkage.  I think they still like to let them airdry for a bit.  I say "they" as I have no first hand info other than logs in my yard.  I have never built a cabin.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Don P

Well, it would appear Elvis has left the building. We are just talking to ourselves anyway  :D

Y'all are confusing settlement and shrinkage. Shrinkage is, or can be, just one factor in settlement.

Just a thinking exercise. If the outer shell, say an inch, of a log or timber is approaching equilibrium and we know dry wood is twice as strong as green, are we a good bit closer to dimension than if the same timber were dead green? If you've watched the arguments made it is always couched in green vs fully dry, which I've also seen in the argument takes 40 years  ;D. In other words is any better than none?

More stuff to think about on the wonderfulness of allowing for settlement. Stairs. Assume the second floor is going to drop 5", ~5%. You are allowed no more than 3/8" variation in a run of stairs and 2° max out of level. How are you going to do that?

A full log gable with a common rafter system, again, how are you going to accommodate the dropping gable wall within a fixed triangle?

Just more fun stuff to ponder on.

DonW

The obstruction in the rafter is at the joint at the peak so a gap would have to be incorporated to allow for the drop. How's that?
Hjartum yxa, nothing less than breitbeil/bandhacke combo.

firefighter ontheside

If I remember correctly, Senty would not build log gables or at least he didn't recommend it.  He would not build log interior walls either because of the different rates of logs drying.  I don't remember the exact dimensions, but I know I built my stairs to have the bottom step to the landing a little taller than the rest and now it is a little shorter than the rest.  The full log wall was 10' tall, but the bearing point in the wall for the stairs is more like 8' so there was not as much shrinkage to deal with as far as the stairs were concerned.  I used to know all this stuff perfectly, but over 20 years later its a bit foggy.
Woodmizer LT15
Kubota Grand L4200
Stihl 025, MS261 and MS362
2017 F350 Diesel 4WD
Kawasaki Mule 4010
1998 Dodge 3500 Flatbed

Don P

DonW, in that area from the plate up, the log gable is what is dropping, the rafters are stationary in relation. There is no really good solution.

For stairs you can slide along the floor going out of level, you can absorb the settlement in the top step or a combination, or you can build the finish stairs later.

I pegged a couple of EWP timbers a little bit ago, an 8x8 and an 8x10. I sawed the stack 12-14 months ago, the cover blew off about 4 months in and I keep meaning to recover it, it was an unusually wet year but dry for the past month or two. I used 3" insulated pins. The surface was quite dry, first whack in was 15% on both then climbed to 20% 3" in on the 8x8 and 25% on the 8x10. This is pretty typical. EWP dries rapidly although not as fast as SYP and these were sawn timbers but it does give a little perspective on the claims that one has to build with green heavy timber. The ones I really enjoy is folks who wring their hands on the internet gathering opinions for several years before making the decision to build green  ::) :D.

Don P

I'm still bouncing through books and tables for the inspector and was in my calcs a minute ago banging out something else. I'd forgotten I wrote a log shrinkage calc based on the code equations;
Log Wall Shrinkage Calculator (timbertoolbox.com)

They do differentiate and shrinkage can be just one portion of overall settlement, as I recall there's several more pages in the code to get there if designing by the book. Anyway just more background.

Joe Hillmann

One reason to season the logs  is they become lighter and easier to move.  I milled a bunch of D-logs last summer and it was all I could do to get them in the drying stack with ramps.  Now nine months later I can put a log over my shoulder and carry it with no problem.  And I assume they will continue to lose weight as the dry more.

kantuckid

In my (senior, worn out body's) world a dry log is fairly heavy... :D I built my home solo to the tops of the first floor windows off the bed of my log truck onto the subfloor, green SYP logs, sizes from 20' down, 6" thick by 8 to 11" diameter. Now we know why my body is broken? I should have waited 7-8 years for them to dry out as I now learn.  ;)
Kan=Kansas;tuck=Kentucky;kid=what I'm not

doc henderson

but then (now) you are even older!   ;) :)
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

kantuckid

Older is VG as the alternative is sucky.  :D 
Life as I knew it with my tractor operational was better than right now though. Our main garden has not been harrowed or tilled and can't find someone close enough so maybe first year with no main garden for a very long time. Got lots of maters & peppers though.  
Kan=Kansas;tuck=Kentucky;kid=what I'm not

Iommi

Quote from: DonW on May 20, 2021, 03:25:40 PM
Starting construction directly after felling is the standard procedure with the kind of construction you mention. There are many so called Scandinavian methods so it's not clear which particular method you intend. Will the logs be hewn on the in and outsides? Almost all Scandinavian log buildings are.  Which corner joint, there are many?
The moisture issue you mention is not a concern at all unless you misguidedly try sealing joints with some non-permeable material. Structurally you will have to understand and accommodate for significant shrinkage in the corner joint and anywhere vertical elements interact with horizontals, door jambs, window jambs and so on and so on as well as the roof
The corner would be with the saddle notch, and the belly of the logs grooved (full scribbing method) so I can put insulating in the groove. I was just concerned that the belly groove traps the humidity and the mold, especially with the sealing rubber joint that I want to put all around the groove.

kantuckid

Another e.g. of how my own home build had an interaction between a horizontal log wall and a vertical structural member is the log porch posts holding the porch roof. They stay the same height, while the wall lowers as it dries. 
Play with that one awhile... ;D 

An interior masonry chimney is yet another challenge. 
Windows and door openings are far from the sole drying allowance areas. 

Taking a look/see at the materials typically sold by a log/timber frame supply house will give you a basic indication of some materials used for these constructions. 

Green wood monstrosity: 
We shared, with two of our sons families, renting a huge, recently built rough lumber cabin incorporating many large beams and mostly all was air dried green built. Stayed there in N GA mtns the weekend before last on the Toccoa River where we ran the river in kayaks for 3 days. It was mostly built to be rented as an event cabin (it had only been rented a couple of times so far so nearly new) and had four stone fireplaces, two indoors, two at a deck and stacked- or so I thought at first!
 I noticed the floors were not level inside near the fireplaces and then saw the same thing on the deck upper fireplace. I got curious what was holding the immense upper decks fireplace and walked underneath it to see. I cringed to learn it was a disaster in the making IMO. No way the wooden beam arrangement under the tons of rock will stay as built! Not to mention that we tried a marshmellow fire in the upper deck for the kids and it didn't even draw properly. 
gain, this is designed as mostly a weddings, etc., event place which will have far greater floor loads than we happened to be. Looked neat though and can't say as I've ever seen kitchen counters covered with granite that are over 40' long-had a kitchen island that was ~ 30' long in granite. The two bar counters in the basement are ~25' long! 

I hope nobody gets hurt there. 
It was built entirely of green lumber but has a number of faulty design features is the (sort-of) connection to this thread.
Kan=Kansas;tuck=Kentucky;kid=what I'm not

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