The Chop-Saw Gets the Axe
The first wall is completed. Although the mortar looks dry — it’s not! You can see the logs near the top have absorbed some of the water. This photo was taken one day after completion.
After numerous attempts at preventing logs from flying off the table, I have shelved the chopsaw idea. The chopsaw does work when cutting long logs to 8″ lengths, but when attempting to cut 16″ logs in half, it was difficult to keep the logs steady. It was impossible to keep the saw from bucking while cutting a log with knots in it. I would imagine that if I was creative enough I could make a vice that would keep the logs steady, but the amount of time to set up each log into position would be rather time consuming.
As an alternative, I tried using a 10″ sliding, compound miter saw. To my surprise I was able to cut most of the logs in one to two passes. The cuts are extremely smooth. A smoother cut reduces exposed log-end surface area and reduces some of the waste created by a chain saw blade. (A 12″ sliding, compound miter saw would probably be better, but I’ll just plod along with what I’ve got.)
After cutting about four hours worth of logs, I feel this is the best way to cut the 16″ logs in half. I’ve had no problems with the logs binding and I can cut the logs just about as fast as using a chain saw. The only downside to the saw is large round logs. There’s no way to cut large round logs with a miter saw. (The largest miter saw that I have seen are 12″. There might be some that are larger, but I would imagine they would be cost prohibitive.) With that said, I personally don’t want large round logs in the walls. The larger a round log, the bigger the check will be once it dries. I’d much rather take a large round log and split it first, preventing any checks. No checks, means less air leaks in the wall and/or chances of insects making a home in the logs.
To summarize, I have great safety concerns with using the chop saw and I would not recommend using it. A miter saw (in my opinion) is a great investment for post and beam work or general carpentry. Why not use it for cutting split wood and smaller round logs? I feel much safer using the miter saw and the blade has held up just fine cutting red pine and cedar.
So how’s the house coming along?
The first wall is completed. Although the mortar looks dry — it’s not! You can see the logs near the top have absorbed some of the water. This photo was taken one day after completion.
Slow. The last few weeks has been a bit frustrating. Not because of the walls, but outside factors. First, I had to attend our dear cat who required eye surgery. (It’s in my contract as house husband to play nurse on occasion.) After being home three days with the cat, I was about to load up the truck when I noticed a puddle of fuel under it. To make a long story short, I didn’t have my truck for four days.
Once I finally arrived on site, I completed the first wall. I figure it took a bit over 5 days of work. I should be able to get into a rhythm that will cut the hours back a bit, but it’s going to take some practice.
The first wall was made with about 65% paper, 35% mortar mix. Although I have been satisfied with the results, I have a few observations:
After two weeks, the wall has solidified but it’s still wet! (My sample walls made last year were quite a bit smaller than 8′ x 8′ and dried much quicker.)
A small 1/8″ gap appeared at the top of the wall within one hour after completion. This gap has not gotten any larger. I believe this gap was caused by compression of the paper in the wall.
The mortar was easy to point, but there’s a “cottage cheese” texture to the mortar, leaving the wall a bit bumpy but still quite smooth.
The wall required between 7 and 8 bags of mortar mix. Granted, I could have gone with a lower percentage of mortar mix, but it didn’t have the same “plasticity” to the mortar. (This could probably be corrected by adding lime to the mix.)
The outside 1/4″ to 1/2″ of the logs soaked up water from the mix.. Because the walls are comprised of cedar and red pine, I am not too worried about expansion problems, but harder woods I would not chance.
The second wall borders the utility room area. There’s a dryer vent and a number of other access tubes that have been mortared into the wall for utility hookups. Remember to plan your walls ahead of time. Each wall that is being built should have its own blueprint for door and window placement as well as any electrical fixtures that will need to be installed.
After contemplating the above results, the second wall’s recipe has been modified to include sand into the mix. This has reduced the R value of the mortar, but considering the house will have double cordwood walls with insulation in between, the house can afford to lose some R value.
The first wall is completed. Although the mortar looks dry — it’s not! You can see the logs near the top have absorbed some of the water. This photo was taken one day after completion.
The second wall is about half way done and so far so good. The added sand has had quite a positive effect. The mortar sets up faster and seems to bond better. This is probably due to less water in the mix. Wall stability has also improved with the rapid setup time.
The first walls, by the way are towards the back of the house. Testing a few mixes here doesn’t concern me if they dry to a different color. I feel confident that a mix of sand, paper and mortar mix will be the recipe of choice. It will just take a little more refinement to tweak the recipe.
A special thanks to Tom, Nick, Deb, Rick and Christal who came out to lend a hand this last weekend. (I you’d like to get some hands-on experience with cordwood construction, feel free to drop me a line.)