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square hewn log notching.....

Started by Papa, April 21, 2014, 01:59:00 PM

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Papa

So.....I got my granfors brooks 1900... i got 65 good straight white oak....after i hew them square i need to notch them....looking for some input on notching styles and links to free jig plans or etc. ...shooting for maybe 2 1/2 to 3 in gap between logs dont want to spend a fortune on chinking....i like the uniform look to the corners with the v notch or the square notch...they seem easier too but could go with the half dovetail if i had to. Does anyone have diminsions etc to cut these notches or could tell me how to figure it out without having to buy plans like i seen for the half dovetail notch.

Also...i planning to build with hewn logs a 24 ft by 16 structure which is going to be a canning kitchen and dining room then i want to go off that structure in stone as i have a good supply of really awesome building stone..does anyone have any ideas how to connect the log structure into the stone . Only thing I can think of myself is to nail lots of nails up and down the inside corners of the log structure and leave them protruding out and maybe stick some chicken wire over them and mortar into that area and start a wall of stone from that but that doesnt sound like a very good idea  :-\  ?

Roger Nair

First off, I'm a timber framer not a log builder, so for what it's worth... I have a serious reservation over your log wall to stone wall connection, a green log wall will have a high degree of shrinkage in height as the logs season, the chicken wire and mortar detail is, imho, doomed to serious degrade.  Whatever details you come up with will have to allow for the logs to slide and bypass the stone as the logs season or in the long view, the building phases could be staged to allow for seasoning but that can require a few years.

An optimist believes this is the best of all possible worlds, the pessimist fears that the optimist is correct.--James Branch Cabell

D L Bahler

The best way to connect log to stone is to incorporate a vertical timber member. This timber is grooved and into this groove fit tenons on the end of the wall logs. The wall logs must be allowed to move freely in this groove, to account for settling. If a space is desired between log courses, stack blocks between them just beside the vertical member.

The member must be cut short of the top plate of the walls, the exact amount calculated so that it will just close with settling.

The stone then connects to this upright, thus the whole connection remains unaffected by settling.

You then cut a V notch on the upright where the stone wall connects. The mortar is keyed into this notch. This then will provide a fairly good seal. But structurally, the log and timber walls do not and should not be working together due to the very different natures of these materials.

Papa

thanks for the help.....im still a bit confused ....ok when you have a log wall and you cut out to make a chimney from stone...do folks use timber members to connect the stone to wood in that situation? cant you mortar stone directly to wood or? I planned on letting the hewn logs dry for 2 to 2 1/2 years would this make for less shrinkage problems or do the logs need to dry upon themselves stacked to help settle everything together......sorry ...very new to building stuff.   :-\

D L Bahler

The logs will dry some in 2 years, but not through.
There will still be some settling.

Generally, a stone chimney is not attached to the logwork. It should not be. It must be built to be self-supporting.
Also the joints themselves will settle and compress. The amount at any one joint is slight, but overall it does make a difference.

If you use the upright method to attach anything else to it, you can mortar stone to that (but the wood must be 'keyed' because mortar does not bond well to wood.)

Roger Nair

Papa, there are a few facts you must get your head around concerning the drying of wood.  Basically there are two types of wood/water relationships when evaluating moisture content of a log, that is free water and bound water.  Think of a log as a household sponge, take a dry sponge, dip it in water, the sponge expands, wring out the sponge until no more water pours out, put the sponge on a window sill, the sponge dries and returns to it's original size.  The water that was squeezed out of the sponge is free water, removing free water from a sponge or a log has no effect on the size of the log.  The water that remained in the sponge is bound water that has integrated into the cellulose and plumped up the sponge, so the sponge shrinks as bound water is removed.  The same goes for logs, timber and boards.

Good reference material, for free download, is available from the USDA Forest Products Lab, look for The Wood Handbook.  From a library or bookstore look for Understanding Wood by Bruce Hoadley. 

White oak is slow drying by nature, requires shade, proper stickering, air circulation and end treatment.  The rewards come slowly and in the later stage of drying.

An optimist believes this is the best of all possible worlds, the pessimist fears that the optimist is correct.--James Branch Cabell

Thehardway

Papa,

You have chosen well for your logs.  White Oak is a great material for log or timber building if you can deal with the weight of them and the deep checking they a likely to exhibit as they dry and are exposed to sun.

There are plenty of good notching methods out there. Spend an evening at your local Barnes an Noble or library and you should find several books on log home building and how to do the different notches.  from there you can decide which one fits your needs and skills best.

White oak does shrink but primarily laterally and not longitudinally.  For this reason, one must allow for shrinking, settling, and then seasonal movement of expansion and contraction.  Best not to connect directly to the stone, allow a bypass system with room for expansion/contraction joint.

In many old masonry/wood structures a wood to masonry connection was made by embedding attachment wood in the mortar joints into which fasteners could then be driven.  This was more used for panelling, mouldings and siding than for structural wood.  This method did allow for some variance in movement rate.

In the case of your chimney, the chimney should actually be the first thing built.  It should be freestanding, on substantial foundation below the frost line. Easiest way to do it would be to slip form it. This will keep your chimney square, plumb, and within a specific dimension which will make it easy to bring the wall in alignment with it when you build the log portion of the cabin.

Slotted brackets can be affixed to the masonry which allows for settling in the walls at attachment point.  I have also seen iron dowel rods left protruding from masonry to go into vertical wood members that have been slotted to accept them and the ends of the logs that abut the chimney. The function is only to serve to control the wall from leaning in or out over time as it ascends next to the chimney. Settling gaps will need to be left over windows, doors, or anyplace where the wall will settle at a different rate than the main structure.
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jander3

I like 1/2 dovetail.  After hewing, which takes a lifetime....cutting the dovetails in a beam is a pretty quick operation.



  

  

  

 

Papa

those were some great replies fellas, i really appreciate the time took to reply, i have a better idea of what to do now, but still have a lot to figure out yet as well.....right now im trying to figure out how to get this white oak down i cut into yesterday, i knew i shouldnt have tried it without having some help with a tractor and chains, this tree has been in my way of digging out my foundation site, been putting off and cursing thisa tree for past 2 years, and finally yesterday i just had to tear into it and sure enough i screwed it up...it had  lot of lean towards my current house 16 ft away...all the weight and big branches are on side leaning towards my house, notched her real nice and went in with the back cut and it pinched my saw, brely got it out, was dumb enough to try 2 more tries at the backcut and just couldnt get in there before the weight jammed me in. So now since yesterday evening it is sittin there with only 2 more inches of back cut to go but resting on itself and the angled downward dummy backcuts i made. friend is supposed to help with 4wd and chains this evening ...just hope its calm out there today ...live and learn i reckon..if i had that backcut to do again i would have made a small narrow notch ....wedged behind the bar.. and went on with cut...but as dumb as i am i tried to wedge my chain size cut as i got in there....wasnt wide enough to actually wedge...hey ill get the hang of it one of these days. maybe ill get the ole camera out and keep this thread goin so you fellas will have some good entertainment as i try to do things dummies shouldnt try :) thanks again.

routestep

I've cut down a few leaning trees by using a plunge cut into the tree.

I cut a fairly shallow face cut
Then I plunge into the tree, stay way from the face cut and leaving wood on the back side of the trunk
Then cut the back cut mating up with the plunge.

Doing this approach will prevent laddering of the trunk.

I bet there are better explanations with pics over in the other sections.

Frankw

 :new_year:

I am a retired (Dutch) geologist and live with my Filipino wife in the North of Luzon, Philippines on 40 acres of hilly farm land near mountains on the Abra river.
I just joined this forum, planning to build a small log cabin (sauna) LxWxH 10x8x10 feet but haven't got a clue on the notching process. I am cutting some medium pines (1 foot diameter) up the river that I will (partly) peel and cut in 12 feet members but that is about it. I browsed the web but cannot follow the discussions, either too complicated too much advertising and without detailed drawings how to cut a notch. My internet is limited to e-mail only (far from a city) so no UTUBE or video. I had in mind a simple square saddle notch but would like to skip the scribing if possible. No idea how to plug possible gaps as a sauna requires tight fit members....Besides the notching I plan a door above the first member, how to join the members to the door frame? I also need to install an open stone (wood) fire place 2x3 feet with a brick chimney (or metal ducting) on top and a small window (same technique as the door I expect). We have a chain saw and basic carpeting tools (and all the time in the world).

Any drawings of simple (layman) notches and tips would be much appreciated.

Thanks a lot.

Frank


fred in montana

I am the owner of the log jig plans site. Just a FYI- if you send photos of your cabin after you are done, you get your money refunded.
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logdovetailjig.com

Magicman

Welcome to the Forestry Forum, Frankw.   :)
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jander3

1/2 Dovetail Layout for 6" x 8" Timbers (3 1/2" overhang)

The layout takes a forever on the first timber.  After you have done 3 timbers, layout is fast and easy <5 minutes per timber.  Then, with a chainsaw, a hand saw, and slick it takes 10-15 minutes cutting out the notch.   

Make the template out anything stiff that is about 1/4 or 2/8".   You can vary the gap will vary depending on the width of the timber and the angle you choose for the dovetail  .   



  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

 

BCsaw

I agree with Jander, the half dovetail notch is king! Water repellant and it looks good. I have a site that allows you to play with your dimensions of the notch and your gap. Will find it and post.
Inspiration is the ability to "feel" what thousands of others can't!
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Frankw

Thanks Jander, Dovetail looks very rugged but maybe more fitting for square timber, my logs are round and also vary in diameter from 9"-10" so I have a far more primitive notch in mind as attached?

Frank

[attachment deleted by admin]

jander3

Frank,

If you can cut a saddle for your notches, the fit will tighten up over time.     



 



 

To learn the basics about log cabin building Alan Mackie's building with logs provides enough information to get started.

I would fine some practice wood and try to cut a few notches.  Scribbing and cutting takes a day or so to get down.  A chainsaw speeds up the job; again, cutting and brushing the notch takes practice.   

Forum post on building the Stump Ranch (Full Scribe Log Cabin)

https://forestryforum.com/board/index.php/topic,33283.0.html

Frankw

Jon

I am doing that right now with some 2 inch sticks and I can mimic the primitive cut that I have attached earlier (and your lower picture) but my notch looks very different from your top picture (saddle) that shows the cuts at the sides of the upper member fitting in a V type cut in the bottom member, are the cuts for the top and bottom members perhaps different?

Frank

jander3

Frank,

I don't have any decent photos that show how to cut a saddle notch. Below are some photos that give you an idea about a saddle notch.  The groove running lengthwise is the lateral groove so that the log above fits tight.  In your design, with chinking you would not scribe or cut this groove.   

This notch is a round notch with a relief cut at the top.  The saddles are cut into the log before you cut the notch.  That way, the notch from the log above will fit on the saddles for the log you are cutting.  Somewhere around the house I think I have some hand written directions and sketches for notching.  I will check tomorrow, if I can find them I will scan and post them for you.

Jon



  

  

  

  

  

 

Frankw

Jon, thanks for the pictures, it explains the lateral groove well that I was also wondering about. Would appreciate any drawings like I have attached. At the moment I plan to make the notch as illustrated on attached figure 165 A+B+C with some scribing (lateral groove) are you OK with that for the tropics? Our type of pine tree is probably Caribbean Pine, almost no bark (white) probably planted by the Japanese (WWII), no resin-no odor.

Frank

[attachment deleted by admin]

Fundyheather

Hi Frank, others

If you are hewing square anyway, perhaps consider reviewing this long film showing a joint used in Northern Europe and Russia:

https://www.youtube.com/watch?v=hdH9qjpFyw0&list=PLBxFk4XsbOaP3CSA5_AzM0js6kjco4HZz

I used this joint in my sauna, with foam sill gasket spiked down hard between the 'logs' as a seal.  I was using the cores of red spruce in the build, and there was very little shrinkage, maybe because I removed most of the sapwood. 

You need a steel square, measuring tape, circular saw, buck saw, 1" square chisel and pencil to lay this out and cut it.  Sometimes I lost my pencil in the snow and just used a nail.  Sometimes because of a knot, the notch didn't plow up so well using the circular saw; so I cleaned up the slot with an electric chainsaw rather than the 1"chisel.  I have had good luck doing this in 5x5" and 4x5", but I think in the film they are using at least 6x6's.  Kept me in heat all last winter.

jim

  

 

Fundyheather


jander3

Frank,


I found some photos from a little project that might give you an idea on how to cut a notch. Let me know if this makes any sense, notch cutting is hard to explain.  In this case I am scribing the lower member. On a log wall, you would put the log on the building, scribe the log, then, either roll the log back or remove it from the building and cut it.  I take the log off and cut on the ground, but a guy could put up some scaffold bucks and cut with the log rolled back on the building. Anytime the log is on the building, make sure it is dogged in place,  It never ends well if you find your body between a log under the influence of gravity and the planet.

Jon

How to Cut a Notch
For Chinked Cabin With a Chainsaw

The base will be scribed and notched to accept the 1/2 log on top.

 


Log Scriber, set up for normal use, with the pencil on top, for scribing the notch in the bottom a new log.




Before you use a scriber, check it on a level line (draw a plumb line on a surface that is plumb).   You set the desired gap on the scriber. The gap is the amount that you want to drop the log. For example, if you have a 6" gap when you put the new log on the building and you want 1.5" gap for chinking, you set the scriber for 4.5".  The setting might be different on each end of the log as the gap will not be equal when you put the new log on the building.  You want a setting that gives you a generally uniform gap after the log is in place.  The scriber points are placed on the level line and the level is adjusted until the bubble is centered.    You can see in this photo that I reversed the point and the pencil because I will be notching the bottom member.

 


Scribing the line.  Hold lightly, pull toward you; keep the bubble centered. Easier said than done.  Scribing takes practice, stay with it.  Practice a few notches on some crap wood.  I use pencils with indelible ink.   I spray the log with water from a spray bottle before scribing, and then I spray again after to set the ink.   

 
 

When the scribing is complete, double check and make sure you have a good line before removing the log, you will never get the log back in the same position for a do-over.   

 


Remove the log (or roll it back), then, score the line with a chisel (flat-side out). Score as close the line as you can, leave the line.  This chisel was a little big for this work, but it was handy. 

 


You want to create a sharp edge that will meet up with the other member when you roll the log in place. The score line is 1/4" or 3/8" deep or so.

 


Remove the waste wood.  On a wall log normally a couple of diagonal cuts (for larger notches split the waste wood down the center with a cut then make your diagonal cuts) and then whack out the triangle pieces with an axe, hammer, or adze.  Stay back from the scribe line.

 


Note: Shaving and brushing take some practice, your first notches will be Butt-Ugly.  No worries stay with it, they will improve.  Keep the top quarter of the front of the saw away from the wood or it will kick-back. For shaving or brushing, I would start with safety chain.    Once I learned, I cut the waste wood with full or semi-chisel chain and then shave and brush with semi-chisel or safety chain.   I've never been able brush well with Full chisel chain.

On each side of the notch, split the work into quarters with a shallow cut.  Then shave each quarter close to the line (within about 1/8") using the front lower portion of the chainsaw bar.  You want to get very close to the line but don't over cut . You are shaving to form a slightly concave shape.

 


Once you have all four quarters shaved, the bottom of the notch will still be rough.  You, then, brush the notch with the tip of your saw (bottom) and bring the work right to the scibe line.  In log building, when you are complete, the entire line should be present; however, you want no wood inside the line. If needed, you can clean up to the line with an axe or adze or handlebar gouge.  Brushing to line is easier than you think. As you near your scribe line, you will produce a sharp edge as the wood is brushed away from the scored line you set with your chisel.   You want a generally concave shape; you do not want a soup bowl. When you lay a straight edge across your notch it should touch the scored edges.  If the straight edge touches any material between the edges, this material will need to be brushed away or your log will hang-up when you try to fit it up.

 


Fit up the log. This step might require you to roll the log back a number of times to make adjustments to your notch if you encounter any hangups.  You want to make sure the fit is tight.  In this case, I could have notched the top log into the base.  However, due to the size difference it was easier to notch the base.

 


Fit up completed.  Again, for log building the notch would be in the top.

 






Frankw

Very clear Jon, but what happens to the next layer (your 1/2 log on top) are those logs scribed and notched again into the lower log? Is each log scribed and notched at the top and bottom (both sides) or only on one side (top)?
Frank

jander3

You only notch the bottom of the log.  You put the next log on the wall (Butt to Tip), scribe the notch, and then cut the notch into the bottom of the new log; roll the new log into place and verify fit-up.

 



The previous post was a simple round notch; it works fine.  Notch the bottom of the log, stack it, and move on.  Big logs don't move. Some builders will use a lock-notch for the bottom and top rows.  If you are worried about things shifting, in lieu of a lock-notch, a timber screw placed into the round notch joint would work just as well. Below is a photo of a lock-notch (just like Lincoln Logs). The layout of these notches is a little more complicated.  To cut a lock-notch, the scriber is set up with two pencils and then you establish the lock-notch height and transfer the measurement from one log to the other using your gap setting so the lock notch  matches up when you put the pieces together.   

    



Because a round notch sometimes opens up with time and loosens up, builders developed the saddle notch.  To cut a saddle notch - before scribing, cut the saddles into the new log (you can see the saddles below),  The new log will sit on the saddle area of the log below.  Scribe like above; you will be scribing onto the saddle area.  After scribing, draw in a little 3/8" rectangle at the top of the notch for a relief cut.  Score and cut as above.  The saddle notch method ensures that  the notch will tighten up over time.   The saddle also helps to shed water if the structure gets wet.

To cut a saddle, with the log set up on some notching stumps (about 2 feet off the ground, or whatever height is comfortable to you), use the top portion of your chainsaw bar to make the cut (pull  the saw backwards).  Pulling the bar backward will make the saddle cut much smoother as compared to cutting with the  lower portion of the bar (as you would normally cut). Saddle length is about the the length of a small level 18"-24".  You cut the saddle so there is about 2 or 3 inches of round log on the top and it extends to about 1" or 2" above the bottom of the log.

 

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