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Timber framing vs Log

Started by Rob30, May 16, 2019, 08:17:39 AM

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Rob30

I don't want to start any fights here, but I am looking for pros and cons for each. Both for the build and after. I believe a dove tail log home will be the easiest and fastest way for me to build. Plus I can build with green logs, a big plus because I am harvesting off my own property as I build. Timber framing I believe will  will be better insulated, easier to wire and plumb. Do timbers need to be dry? A lot more precision and  unique cutting and fastening with timber framing as well.

Brad_bb

It just comes down to what you prefer/want/style.  You usually timberframe green.  The only exception I know of is when people use vaccum kiln dried coastal Doug fir.  Otherwise the other 99 percent of the time it's green.  I'm thinking log home would take more trees versus the timberframe.  Yes there are some benefits to TF over Log as you mentioned.  I like SIPS for roofs, but not for walls(cause you end up changing electrical and plumbing etc as you go along usually).  Don't be too intimidated by TF.  It usually seems to be intimidating before you learn how it's done.  The layout technique is very logical once you learn it.  Taking a 5 day workshop would go a long way to taking the mystery out of it.  It did for me. I'm planning a build right now.  I've been milling timbers for a few years for it.  I mill them a little oversize and let them stabilize for a year, move however they will move (which hasn't been much at all), and then final size them closer to build time.  There are two ways to handle timber movement.  One is how I just mentioned.  This will help assure that in the time between cutting the joinery and assembling the frame, you won't have any big movement, warpage, etc.  The other method is to cut them to size, cut your joinery and quickly get it assembled before it can move.  That way it will dry as an assembly be held together while drying.  Either way works.  The latter is better for professional timber shops who will have many guys cuttting the frame to finish it quickly and get it up quickly.  For an owner build, the former is good.   There are lot of things you can be doing before you start the build.  Build timber sawhorses - not trestle horses.  Horses that are light to move, yet strong for heavy timbers.  PM me if you want me to send you dimensioned pics of the design I use.  You can by or make pegs.  I buy some octagonal blanks from another framer and I make some myself.  They are split from clear straight grain 16" log chunks.  Then pointed on the end with a shaving horse and draw knife. You can also build a shaving horse. Then I have a sizing die that I drive them through if doing a line to line fit.  Or you can taper 3/4 of the length of the peg on the shave horse if doing draw bore fit.  Once you're done on the shave horse, let them dry for a couple months, and then drive them through the sizing die if needed.  FYI you might also be able to hire an itinerant timber framer for whatever length of time needed to help you get started.  Plus you have the FF for help/advice too.  Again, it really just boiled down to what you really want.  You could also do a hybrid home of timberframe and conventional 2x6 framing. Or do part of the house TF and another part log?  I've seen that.  Like a log cabin attached.  or a log cabin at the center.
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

Rob30

Thanks for all the info. I will have to look keep looking into the TF. I am not concerned so much about logs, I have enough for several log homes. I am thinking more about after. I know log homes can demand a lot of upkeep. Also the only insulation is the 8-10 inch log, which has a relatively low insulation value. Where as the TF would have better insulation in between the timbers. I like the idea of SIPS for roofing, I was also thinking of walls, but I will have to consider your comments on the issue. 

barbender

What has always got me with a TF, is they are typically double framed to provide for insulation etc. What I mean is, you have the TF, that is self supporting. Then (especially if using SIPS) you wrap it with another structure that also could be self supporting. It seems redundant to me. Don't get me wrong, I absolutely love the way a TF looks. Myself, I'd do more of a hybrid design with conventional frames or sips walls, with a TF roof structure.
Too many irons in the fire

Don P

A heavy timber roof is where you get the most visual appeal, it can be on log or framed walls. Mixing settling log walls and non settling walls takes quite a bit of planning and thought, And then there is the Hudson Bay Company method of vertical corners and posts that support the roof with log infill between the posts.

Hilltop366

I've never made a log structure but the part that appeals to me besides the look is if you have your own logs, time and skills it could be very low cost with minimal need for outside purchases for the basic structure. The log includes all the components of the wall: Exterior cladding, load bearing structure, insulation/thermal mass, interior of wall surface. 

Raider Bill

Just my .02... We built a log cabin on the Tenn property. It is a constant hassle just fighting the boring bees alone.
The First 70 years of childhood is always the hardest.

barbender

I would be less inclined toward a log structure down south, for sure. There would always be something trying to eat it😊 Up here, as long as you keep the walls dry and prevent decay from setting in, the bugs will leave it alone.
Too many irons in the fire

Brad_bb

Rob should be ok either way in Canada. Shouldn't be any borer bees up there.  Where I'm from in IL, we don't have borer bees.  I'm assuming that the winters get too cold here.  Just 2.5 hours south of there, they are a  problem I can tell you.  I've seen them borer perfect 1/2" tunnels in pine up to 4 feet long.  I haven't seen them boring in hardwood yet(with the exception of Tulip Poplar).

Barbender you are right to an extent.  There is structural redundancy often in a timberframe.  While a frame may support the roof, the walls do not.  They are there to close the envelope.  Their structure is generally not needed.  But attaching them to the frame does give additional, albeit not necessary, rigidity.  In the old days they's probably just sheath the frame.  Many times they wouldn't even insulate.  We need the 2x6 walls today as a structure to hold our electrical and plumbing, and our insulation.
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

TW

It has a lot to do with what sort of logs you have access to and other local factors.

The typical European style timberframe is made from rather short lengths of timber and the infills are traditionally either wattle and daub which makes use of all twigs and other leftovers or brick set in lime mortar making use of the good clay found in fertile lowlands where hardwoods thrive and where farmers thrived too making good timber somewhat valuable. England and large parts of Germany and France.
Other less known types of timberframes developed for use in unheated outbuildings in areas where timber was in limited supply such as parts of western Norway.
In the Faroes all timber had to be imported by ship so they built timberframed farmhouses with infills of half inch thick tongue and groove boards all inside thick drystone walls. Both clay and sand and lime were in very short supply.

Corner posts and log infills were traditionally used in sparsely populated areas of hardwood forests where timber was plentiful and cheap enough to use log infills. For instance Blekinge in southern Sweden. The same type of construction was also used in certain places where pine trees tended to become short and crooked and hence not suitable for log building for instance Gotland.

Scribe fitted log walls were generally used in cold areas where tall and straight pine or spruce trees were plentiful. Scribed logs with moss in the long groove makes very durable and surprisingly well insulated and draught proof wall. Especially when using one of the more complex corner notches. Therefore this was the dominant building methods in most of Norway and Sweden and Finland and northern Russia where the climate is harsh.
In the Alps they have their own tongue and groove variety which doesn't shed water as easily as ordinary scribed walls but that was compensated for by making huge roof overhangs.

Chinked log walls were common in Romania and in a few other places where people were very very very poor while tall straight conifers were plentiful and the climate rather warm and moderate. Chinked walls were also used for temporary buildings in many areas of coniferous forests.

No wonder many settlers in America chose a chinked log cabin for their first temporary home. To many that was a well known method of improvising a temporary dwelling.

Don P

Chinked log homes were sometimes temporary but not necessarily so. In many cases log construction was simply a horizontal method of framing the walls. Later, furring strips were applied inside and out, lap siding clad the exterior, lath and plaster was applied to the interior and the humble log cabin became a frame farmhouse. I've worked on several homes where the current owner didn't realize there were logs behind the walls. Back then living in a log house was not thought of the same as today. Nowadays as it is fashionable to live in a log house I've stripped several back to that original cabin. We are funny creatures.

Actually there is more structural redundancy in a stick frame than in a timberframe. If you lose a member in a stick frame the adjoining lightly loaded closely spaced members are usually more than capable of bearing the load. When you lose a member in a timberframe the next bearing element can be, and often is, quite a bit of overload away, "many hands make light work".

Absent rigid moment resisting frames (steel), the wall sheathing or construction typically provides bracing to the building frame. In a green frame which subsequently shrinks away from the braces be conservative.

 Here's a little experiment you can try to show that. Build a green post and bolster assembly with Y bracing, make it all nice and tight.



Don't peg the braces. A year or more later drive the braces up with a mallet. Notice the amount you would need to shim the post mortises to have them do work. As the post shrinks in width the length of the brace would need to be longer to maintain bearing. Disassemble and notice the angle on the 45° ends of the braces, they will be more acute than when first cut. The bearing will be on a point which needs to compress until there is enough flat surface to bear the bracing load.

This all relates to the amount of rotation those bracing elements would allow before their bearing faces begin to do work. As a building begins to lean what was a vertical load begins to take on a horizontal component, that is a self feeding problem you do not want. What I'm saying here is it is better to use the walls as the bracing element than to rely on the TF braces to provide that.

Here nor there just thoughts that came to mind as I was reading.

Stephen1

I have a scribed log cabin and am now going to build a TF screened addition to my cottage. I did a 3 day TF course with jim rogers a few years ago. I am going to get my neighbour to TF a kit with my wood. 
I do not believe either method is easier, harder, or faster,  they both are work. 
I stain a part of my cabin every year, different walls need more or less stain depending on the sun. I use a garden sprayer and car wash brush for all my wood staining, fast and simple. 
The log cabin is warm and the logs were small, 8-12" so I could lift them by hand. Once the logs are warm they stay warm. I used to turn the heat off and would spend 3 days trying to warm the cabin up to stay in it. Now I leave the temp at 40F and can warm the cabin in 3-4 hours. Thermal mass is why a log home is warm not the R factor. My roof is 8" sips, R40 I believe. 
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D L Bahler

Regarding redundancy in the walls, this is not a negative. Good carpenters are intentionally building redundancy into houses all the time. An over-engineered structure is one that's going to stand up to the abuses of time. 

I'm far more interested in performance myself. I'm pretty sold on the idea of a solid wood exterior, such as log walls, with an inboard insulation system and modern interior. 

As to the redundancy problem with SIP-wrapped TF's, that's not the issue in my mind. It seems like an excessive system, where your timber frame is nothing more than an expensive trim package that adds a bit of structural reinforcement. Which isn't the same as saying it's redundant. I'm not a huge fan of SIP's, mostly because I'm not a fan of foam. But that's personal preference.
Like others have pointed out, think about what's important to you in having a timber frame and build for that. Everything else might as well be conventionally framed. Heavy timber roof or floor systems can add a nice touch along with some other timber accents. 

If you have the trees (actually even if you don't) and you're willing to do all the work yourself, you can't beat the price of log building. Especially not if you're going with interlocking corner, chinkless construction. You can put up a modest house for pretty cheap. If you want to simplify the process even more, modify the structure with upright load-bearing posts so you can stick frame interior walls with no concern over log movement.

Don, I like your post and brace illustration. This is the main reason why Central European builders abandoned corner bracing entirely and instead went with "Streben", which are more or less just posts set in at an angle. The idea behind them is that they do not loosen as the timbers shrink. 

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