Butt and pass log cabin

In the process of building a butt and pass log cabin out of milled logs. 8” round with flats on top and bottom. Anyone with experience with this style of building?

Hi Yve, welcome to Permies.

I'm currently building a log cabin. Mine is a little different, with flat appalachian style logs and dovetail corners, but I understand butt & pass corners. I'll certainly try to help if I can. What sort of questions do you have?

Well it’s only 8” logs do I need 1/2” rebar or can I use 3/8”. I understand that a 2’ spacing is best? So I predrill the top log and pound in the second right?Nothing sharpened! Corners, where mine are round inside instead of flat, where they meet in the corner, Iam guessing I’ll have to router or flatten an 8” circle for the log to butt against? Sorry for all the questions but you wouldn’t believe how little info there is out there on this method. I asked on another forum but the only response I get is to take a course from one of their buddies or so it seems. They must’ve getting a commission lol. Anyways thanks and any info would be great

I myself like to over-do things a little bit. For example, in the footing of the cabin I'm building, I chose to put in three courses of 5/8" rebar and pour 5000psi concrete, but in Tennessee two courses of 1/2" rebar are all that's required for a residential footing. I chose to do that because I was thinking "I only get to do this once", and the cost difference between the thicker rebar and an extra course wasn't much. Having said all that, I'm pretty sure 3/8" rebar is sufficient to secure your logs, but if it were my cabin, I would pay the extra few dollars and use 1/2" rebar. I would also drill pilot holes for the entire length of rebar. It's gonna be a bear of a job to pound rebar through a log without one, if it will even go at all and not split the log. The 2 foot spacing sounds right, I believe that's how far apart the fasteners in my logs are.

While on the subject of tying logs together, I chatted with a guy who has 30 years under his belt of building log homes, and he was telling me about how things were built when he started and what's changed over the years. Rebar in logs is one of them. He used to use rebar, but some time ago timber screws came on the market, that's all he uses now and those are what's tying the logs together in my home. One brand of these types of fasteners is Timberlok. With these, there's no predrilling pilot holes and there's no swinging a 5lb sledge hammer either :) I've included a picture below of what these screws look like.

As far as the inside corners go, either way you describe can work. I think flattening one log for the other to butt against might be easier than using a saw to cope a radius on the end of a log to neatly mate with the other one in the corner. I don't think either way is wrong, it just depends on the appearance that you want.

I hope all this helps!

Thanks bud, I must say I have gottten more info from one reply on this forum than I got from half dozen others. Thanks again. As for the screws did you buy yours in the states or in Canada? Would they be same spacing? I was also going to put ready (speed)rod at the corners and possibly  middle walls. Is this necessary with the screws, I know they recommend it with rebar.

I got my screws here in the states but I imagine they're readily available in Canada. If you do choose to go with timber screws instead of rebar, just make sure you get a screw long enough to go through the first log entirely and have the threaded portion fully into the log below. While I am not a professional log home builder, I think 24" spacing on the screws will be adequate.

By ready rod or speed rod, do you mean threaded rod? If it is, I'm thinking it's recommended with rebar as the logs and rebar can move and slide past each other, thus having the threaded rod to clamp & squeeze everything together. I'm going to hazard a guess and say it is not needed if using the timber screws, since the screws themselves will be applying that squeezing force to hold everything tight. I only say this since timber screws were used in my log cabin to hold the logs in place and there is no threaded rod tying anything together. Granted my log cabin has dovetail corners which are pretty tight and don't allow for much movement at all. Thinking about the butt & pass corners, it may be a good idea to also have threaded rod through those. It'll really help make for a solid corner and also help minimize any log movement through the changes in seasons.

Thanks will probably put some rods at the corners. Yes speed rod, threaded rod, ready rod all the same. Going to check out them screws and see pricing compared to rebar. Also have to consider the cutting and extra work to the rebar. If the screws are suffice to use Iam guessing 3/8 rebar should be good. Going with sill gasket between my logs. Cabin is going to be 24 x 28, that’s a lot of screws! What kinda roof did you put on your build? Was thinking ceiling over bedrooms and a higher ceiling over rest with open log concept,if that makes sense

Yve, it sounds like it's going to be a solid cabin. One tip I'd like to offer, and you may already know and are going to do this, is to immediately caulk all the checks in the logs that are going in level or downhill. I didn't do this right away and was going to give the logs 6-12 months to "settle" and let the checks open up and have the majority of the new log movement take place. One day a rather gusty storm came thru, blowing heavy rain onto one side of the cabin, and water came thru some checks at the seams and into the interior behind where my kitchen cabinets were going. Luckily this rain storm came and revealed the compromising leaks to me before I covered things up. Had this storm not happened, months of water infiltration may have happened setting up conditions for rot to get underway. I gave the checks a few nice sunny days to dry out and proceeded to caulk them.

If you care to, please share some pictures of your project. I (and I'm sure some others here on Permies) would love to see some pics of your cabin. Good luck on your build!

How much do you let the logs pass each other on the corners?

I'm definitely going to second everything James said.  While I've not built a log cabin, I've used timerloks in place of  rebar and lag screws in several other applications and have been most happy with them.  They drive easy and hold very well.  Also make sure you get them long enough to make a complete pass through of the upper log and at least the thread length on the second log, if not further.  

Yve Leroy wrote:How much do you let the logs pass each other on the corners?

Hey Yve, I hope your cabin is going well. I think this is entirely up to you, and there's not really a right or wrong way. The pass should go to a minimum of the exterior face of the neighboring log, but that will yield square corners with no real pass extending out into mid-air. Here's a couple pics. One builder chose a nice uniform appearance with the same length on both sides, the other builder chose to get funky and make them all different.

Thanks again James. I figure 6-8” .I got my floor all down and insulated . Getting ready to start laying logs soon. Another question for you if I may, do you lay two short logs between two long ones or go around with each log passing the end of the other? Hope that makes sense? Example cabin 24x28, do you put the two 24s between the 28s or go around with the end of one 24 passing the end of the 28?

I think it's a matter of appearance consistency. I myself would start the first course with a two 24's between two 28's style. If I'm reading you correct on the other one you described, each one passes the other, in a pinwheel style? I think for corner strength and rigidity, keeping a log either as a pass log or a butt log may be preferred.

I would post some pics but for some reason it won’t let me post

Hey Yve!

Here's a link on adding images to a post that I hope will help ya out. https://permies.com/t/61133/Post-Image-Permies

If the images are on your computer/phone I suggest the attachments button to upload the picture. It's located at the bottom left corner of the text box you type in when making a reply. Here's what it looks like:

I hope it works. I'd love to see some pics of what you've done!

Ah-ha! I quoted Yve Leroy's post and deleted what looked like extra code. I think I got the pictures!

Yve Leroy wrote:

Thanks Nicole

That's gonna be a nice cabin Yve. Thanks for sharing some pictures!

I’m currently sawing timbers to build my square log log cabin. Butt and pass. I’m trying to use up my older logs since I have so many. Yellow pine bark has already fell off. Some feel great just poking them with a pocket knife, some have a soft spot or two but still take a good amount of pressure to press the knife in. They are soaking wet now from being on ground and all the rain we’ve had. Will they still be ok for building? I’m in hopes they will dry really good and seal them good and be good to go? Any info is appreciated

Hi Michael! Welcome to permies. Here are my thoughts on your pine logs. I recommend letting them dry out as much as possible before stacking and sealing. If the logs are stacked and/or sealed with too much residual moisture they can begin to rot. I think it would be a real kick in the gut to spend the time, labor and money building a beautiful log cabin and have decaying logs showing up in 5 or 10years. Small handheld moisture meters can be picked up for $30 or $40 bucks. I bought one to use when building my cabin. If they can dry out to a moisture content of less than 15% they ought to be ready to go. Some folks say 20% moisture content will prevent fungal decay in wood. Over 20% will keep decaying organisms alive, and generally speaking, over 30% moisture content allows decaying organisms to flourish and rapid decay can occur. Hope this helps!

Hi guys got another question for you, I know a lot of people use angle iron on the side of their logs along the vertical sides of doors and windows. Does anyone just use flatbar instead of angle in the ends of the logs either flat or sideways in their logs??