By
Wayne Thompson
This article is a “how-to” for building a simple log cabin, c. 1861-65, by soldiers in the eastern theatre. These cabins were built by green troops who manned the Potomac River defense line in early 1861, as well as by veteran troops through 1864-65. This cabin style would be appropriate for either a US or CS living history presentation, and could be used for shelter at other appropriate venues.
If you are starting with standing timber {1}, you will need the following tools:
** Felling axes (single
or double bitted)
** “Buck” saws, large
enough to cut through the logs
** One or two 10-foot
lengths of 5/8” or ¾” manila rope
** Froe and mallet
** Mud trough or “bucket”
barrow
** Shovels, iron rakes
and hoes
** Picks and mattocks
** Hand trowel(s)
** Block plane and draw
knife
** A brace or hand drill,
with a 1/8-inch and 7/8-inch paddle or spoon bit
You may also need the following items to finish your cabin:
** About 50 hand wrought
nails (roughly 1-1/2 to 2 inches in length)
** Hand wrought iron
strap hinges (at least two, for the door) {3}
** Straw or dry grass
** A small barrel or
keg, with the ends removed
** A few feet of bailing
wire
** Small sticks – lots
of them
With these in hand (or lying nearby), you are now ready to start.
Site Preparation
If you have a choice, find a location that is out of the wind, near a source of clean water, and near the timber you need for the cabin. Remove all the vegetation and trees from your site, and far enough outside the cabin dimensions to give you room to move the longer logs and such during construction. Using the shovel and rake, level the floor of your cabin. You can also mark off the inside dimensions of your cabin at this time (the outside dimensions don’t matter).
There is one type of shelter that involves a little digging. {4} Excavate a pit a few feet deep. It should be the same dimensions as your cabin. Some of these “pit cabins” had slab walls in them to stabilize the earthen wall, and to place a dry barrier between the earth and the occupants inside. Others had a raised wooden floor to keep the occupants’ feet out of the mud that inevitably occurs on the dirt floor. In order to make the pit reasonably habitable, you should have a fireplace or stove in it. A step or two on one end also makes getting in and out easier. This style of cabin takes a lot of work to make, but the effort is worth it. Regardless, it was a common shelter, and is an option worthy of consideration. The photographic evidence seems to indicate that the style was more common among the Union soldiers, but that may be because most of the photos I studied were of Union camps (they being far more available than photos of CS camps.
While one crew is clearing and prepping the site, another crew can be bringing the timber in to build the cabin. If enough people are involved, another member of the mess can be scouting out a supply of clay and larger rocks or stones for later use.
The largest group should be the timber crew. Not only do they need to cut down the trees, but also they need to trim the logs and bring them back to the building site. This group should have the fewest interruptions during their work, and as other duties are completed, members should be seeking them out to lend a hand (they’re going to need it). If there are enough people involved, consider building two cabins at the same time. This will permit larger teams for the timberwork, and will reduce the amount of heavy lifting or digging each individual has to do. The “mules” dragging the logs and the men digging out the pits should be rotated often.
Once a tree is brought down, use the axe to trim off the branches, and cut the logs to length with the bucksaw. Any leftover wood can be stacked for firewood and chinking. Pine bows can be gathered for bedding or other use. Start cutting down trees at the farthest point from your cabin and work your way back. This way, as you tire, you will have the least distance to drag the last logs into camp.
You don’t need to pick the logs up off the ground. Using a length of rope, tie a timber hitch around one end of the log. Tie the other end of the rope to the middle of a six-foot long pole. Using two people, drag the log back to camp. The front end of the log should be between the two men dragging it, and lifted about eight inches to a foot off the ground. This is the best way to move a heavy log (if you don’t have a horse). A third man can assist with lifting the log over low obstacles or pushing the back end around corners.
The Foundation and Sill
The first logs you put down are the sill logs. These should be the largest logs you cut. The best wood for this is locust or gum, as it is the most decay-resistant. If you don’t have any, use cedar or cypress. The minimum diameter for the sill logs should be five to six inches for a five-foot high wall, and no more than eight inches for a six to seven foot high wall. Some cabins had rock footers underneath, with the sill logs about one foot off the ground, with plank flooring. Be realistic, most cabins had dirt floors, and the sills rested directly on the ground. {5} The soldiers who built these cabins only needed them for a few months, and rot was not a great concern to them. It is, however, for us. Use solid wood for the sills, and remove all of the bark.
If you are not concerned about absolute fidelity in the details of your cabin, the use of pressure-treated logs for the sill will give you a few years of worry-free service. Pressure-treated logs will eventually turn gray, but until they do, everyone will know you have pressure-treated lumber in your cabin.
Make the sill (and pit) of your cabin as square as you can. The best way to determine square is to measure from one corner to its opposite corner, then do the same for the remaining opposite corners. If the measurements are the same, the cabin is said to be square.
One final note on digging the pit: to avoid the possibility of a the sides of the pit collapsing during or after construction, start the walls of the pen inside the pit, and build up to the desired height. This supports the wall of the pit, and gives a firm foundation for the topside part of the cabin.
Once the sill is laid down, you can proceed to the walls.
Building the “Pen”
Using the axe, cut notches into the ends of the first course of logs, deep enough to let the next course of logs lock into them. There should be no more of a gap between courses than the shape of the log will permit. While some cabins were made of square-hewn timbers, most cabins were little better than wooden pens, just large enough to accommodate the builders and their gear. The quality of workmanship varied from one cabin to the next, as you will see as your own cabin progresses.
Continue building the courses up to the desired height, using the smallest diameter logs at the top. Don’t worry about the door, window(s) or fireplace at this time. The important thing is getting the pen built. Once you finish all but the top course of the pen, you can proceed to the next stage of construction.
Doors and Windows
Most cabins had only a simple door, with no other opening in them. Others had one or two windows, while others had fairly elaborate fireplaces or stoves. This section will deal only with the door and the optional window.
The door is the largest opening you will have to make. Begin by wedging spacers in between the logs from the top to the bottom. The distance between the spacers on each course will determine the width of your door. A good average gap would be about 28 to 32 inches wide. Be certain that the spacers on each side line up from top to bottom.
Using the bucksaw, begin cutting just inside of each spacer, carefully removing each section of log as you go. You do not need to cut the sill log, unless you want the threshold flush with the ground. Again, this varied from one cabin to the next. In any case, it will be easiest to work from the top down. Once this is done you place the last course(s) of logs on to finish the pen.
The door opening should be framed to stabilize the wall, as well as to provide a place to mount the hinges. Where you put the door is up to you, although most of them seem to have been placed in the middle of the front wall of the cabin. When framing the door, try not to go above the top log, so you don’t have a problem with the final log fitting in place. The lintel can be a plank of wood, or a log split in two. Fasten the uprights to the ends of the just-cut logs with nails or wooden pegs (at least one to each log).
The door is made up of planks that have been rived out of logs previously cut to the proper length. The tool needed to do this is called the froe:
Place the froe squarely on the end of the log and strike it solidly on the back of the blade with a wooden mallet {6}, driving it all the way into the wood. Next, pull the handle of the froe to you until the wood begins to separate along the grain. Continue working the froe back and forth, and down the length of the log until it is split in two. Repeat the process on each half until you have enough boards to make the door. Please note that the log cannot be wider than the blade of the froe. I recommend a twelve-inch blade.
If you do not have access to a froe, you can use rough cut planks from a sawmill. The boards need to be between ½ inch to ¾ inch in thickness. This is also how you would make the slabs to wall up the pit.
Try to get the boards as square as possible and lay them side by side. You may need to use a block plane to square the common edges. Nail a board near the top and bottom of the boards, making sure to keep the boards as close together as you can. A diagonal brace can then be added, if needed. The door will be heavy, so use good hinges.
Place the strap hinges on the door, and then brace the door squarely against the frame while securing the hinges to it. Square-head lag bolts are best. Hex-head bolts are too modern to consider, although a blacksmith can make them square-heads, if you want to spend the money on it. Make sure to leave enough clearance for the door to swing freely. You can have the door swing in or out, as you like. Do not use modern door hinges, although if you find period house hinges, these are a nice touch. If you do not have hinges, you can make rope hinges. These would have been common on outbuildings and the homes of slaves as well as “the meaner sort” at the bottom of the social ladder. The rope hinge simply had a length of rope that passed through the door and then through a hole drilled, at an angle, from the center of the frame to the outside of the log. The rope had to be tight enough to hold the door up, but loose enough to let it swing somewhat freely. Greasing the rope and the holes will help reduce the friction, and may preserve the rope for a longer time than untreated rope. The best rope to use is 3/8” or ½” tarred manila. It helps to smooth the holes with sandpaper before running the line through it, but this is not essential. Use petroleum jelly or axle grease, if you need to lubricate the hinges. Cooking grease will encourage mice and such to eat the ropes and the surrounding wood.
Most cabins did not have windows, but some did. If you want to put a simple window in, try this:
1. Make the window small (18” square). If you can cut only halfway through the logs on top and bottom, you keep some of the strength of the wall, and also get a good windowsill out of the deal, too. Angle the sill so rainwater runs out, instead of into, the cabin.
2. Divide the window into four panes with crossed rails and muntons, like this: +. Make two identical sets.
3. Place oiled parchment paper between the two sets of rails and muntons. Use a few small nails or brads to hold everything together.
4. Frame the exterior with more wood of the same dimensions as the rails and muntons. Use brads or small nails to fasten the front and back panels together.
5. Caulk the frame with the same mud you are about to use to “chink” the gaps between the wall logs.
Stringers and Trusses
You should be ready to put a roof on your cabin by now (in fact, one crew could be getting this ready while two or three others are cutting the doorway opening and making the door). There were a number of different roof styles available, and the one you choose should reflect your group’s skills and patience. The two roofs described here will be good for the average, inexperienced reenactor. If you really want to work, make the roof from split-wood shingles.
The first type of roof is the canvas roof. If you choose this type, you will have to wall up the sides of the cabin, or make canvas end closures to block out most drafts. Begin by putting up trusses on each end of the cabin. If your cabin is more than ten feet long, you may need to add another truss in the middle. Assuming that your cabin is ten feet wide, and you add five feet in height for the truss, your canvas needs to be 14’, 1-1/2” {7} wide, plus another 6” for the canvas to hang over the sides of the cabin.
Determining the length
should be obvious. Just measure from one outside end of the cabin to the
other outside end along the length, adding enough material to overhang
the ends. (If you still can’t figure out the length of canvas, I
can’t help you.)
The second roof involves less geometry. This is the plank roof. You will need to make a lot of planks, so this one involves considerably more work (but a lot less math!)
Make the roof planks the same way you made the door planks. They need to be no less than five inches wide, and should be about one foot longer than the width of the cabin. You need enough planks to cover the roof three times over (no, that wasn’t a joke. You need that many planks).
In order to get any rainwater to run off the roof, you will have to add one more log to the front of the cabin. This will give enough pitch for the rain to run off the back of the cabin (you will have to chink and daub the elongated triangle of open space on the ends that this creates). Lay the first layer down all the way across the top of the cabin. Then go back across with the next layer, staggering the rows so that no gap between the planks is over one on the layer below. Place the third layer on top in the same manner. If needed, place some large rocks on top to hold the planks down (you may not need to do that, given the gentle slope of the roof).
Staying Warm
Most cabins had some type of fireplace in them. The most common style mirrored the standard chimney of the day, with fireplace and flue. The materials used ran from first-quality brick and stone, to mud and sticks. We will look at three options in this section.
The first choice is the simplest. Leave an open gable on one end of the cabin at the highest point of the roof. Build a wall of stones or bricks against the wall under the gable, and about three inches thick. Be certain to go out about thirty-six inches along and about the same distance high. This is your fireplace. Any smoke will rise up to the gable, and (maybe) drift outside. If the fire is small, and you keep any blankets or clothing away, this can produce a lot of heat and light, without much risk of burning the cabin down.
If that possibility still bothers you, try a standard fireplace. Cut out an opening in one wall of the cabin, at ground level, and cover the exposed wood in the fireplace with lots of mud. Using small (1/2-inch to 1-inch diameter) sticks and mud, build up the fireplace area. Again, use lots of mud to seal off the fireplace from the wood of the cabin and fireplace.
Many cabin chimneys were made from barrels lined with mud, or a lattice of sticks covered with mud. Both are likely to catch fire, and I cannot recommend this type of fireplace or chimney for that very reason. You could run stovepipe up the middle of the barrel or stick chimney, but even that can ignite the sticks if the fire is too hot. Stovepipe would work better inside the barrel, as there would be a generous gap between the pipe and the wooden barrel. You would have to use wire to set the top of the stovepipe in the center of the top of the barrel, but no one will see that (I think).
The final option is for the pit cabin. Dig a shelf in the back wall of the pit, about halfway down the dirt wall of the cabin. Make a small “rabbit hole” chimney at the back to let the smoke out. If the soil is strong enough, you can get by without a chimney. If not, you can still build up a chimney about two feet high to cover the hole, although many of these fire pits eventually collapsed and were open to the sky. This works fine as long as it’s not raining. Again, cover any exposed logs with lots of mud, and keep the fire small. Some heat will radiate into the cabin, but you may also get a lot of smoke. But, you don’t have to build much of a chimney, either.
Chinking and Daubing
No matter which fireplace you build, it won’t make much difference if you don’t keep the drafts out. The best way to do this is with chinking and daubing between the logs. It can be messy, but it works.
Chinking is the placing of slats of wood between the logs to fill up as much space as possible. The chinks should be the odds and ends from the construction of the cabin, and any other pieces of wood you need to make to fill up all of the large spaces. The wood should be placed to fill up as much open space as possible, but you don’t need to force the chinking in place.
Daub is a mixture of clay and sand, with a little bit of straw or dry grass thrown in as a binder. Mix the ingredients together with enough water to make a thick mud. Lay the mud onto the chinking, and trowel it smooth. Do this inside and out. This is the same material you need for “fireproofing” your fireplace. Seal all the gaps as best you can.
And there you have it, your new cabin. Put whatever furniture you want inside, it’s yours to do with as you see fit. Enjoy.
The Pythagorean Theorem,
A Practical Demonstration
Use this diagram for reference:
Right triangle formed
from cabin roof.
For our purpose, the formula (a*a + b*b = c*c; c X 2,) allows us to determine the width of canvas needed to properly cover a cabin.
As a practical demonstration, let a=3, b=4, and c be half the width of canvas needed.
In the formula, a*a=3x3=9, b*b=4x4=16. Therefor, c*c must equal 25, since 9+16=25.
In order to determine c, we must take the square root of 25, which is 5. This only gives us the width from the middle of our canvas to one end, so we must now double this value, giving us 10.
So, the width of canvas needed to reach the front and back walls of the cabin is ten feet. But, we also must allow for the canvas to overhang the outer sides of the top course of logs, so we should add about four inches per side, or eight inches total.
Thus, the width of canvas for a cabin that is eight feet wide, with a three-foot high ridge, is ten feet, eight inches.
To summarize:
1. Determine the value of a by measuring from the truss down to a point even with the top of the wall and directly below the truss. The value of b is half the length between the front and back walls.
2. Multiply a times a, and b times b. Add these two values together. This gives us c*c.
3. To find c, take the square root of c*c (square root of c*c = c).
4. Multiply c times two.
5. Add a sufficient amount
to the final number to allow for the canvas needed to overhang the top
logs.
(1) If you can afford it, one alternative would be to buy logs already cut to length at a local sawmill. Most likely, you will end up with pine logs, but that’s OK. The logs may have the bark removed, as well. If that is the case, you may want to have the logs cut square. This will give you a tighter fit between logs, and a more uniform appearance. To maintain a more rustic appearance, just have the top and bottom of each log cut (this will also be a little cheaper.
(2) If hand-wrought nails are not available, or too costly, you can use square-cut nails or decorative head nails available at most large hardware stores (Try Home Depot or Lowes to start).
(3) Avoid using modern “store-bought” hinges. This style did not exist at the time of the Civil War. One should also steer clear of modern-made “antique” hinges, as they are too frail to handle the stress of holding a door on the frame. The most correct style is the strap hinge, but other styles did exist. Check with a local blacksmith to see if a set can be made up for your project.
(4) I studied photographs of these “sunken” cabins in such works as “The Photographic History of the Civil War” and the Time-Life series “Echoes of Glory” and “The Civil War”. I would encourage you to consult these volumes to get more ideas on how these structures were erected, as well as reading the many memoirs and biographies of the soldiers who actually built them.
(5) Unless, of course, you are portraying engineers. In that case, you should be building real frame houses and outbuildings (which is what they did).
(6) Notice that the handle of the froe will be pointing away from the log while you are driving the blade into the log. This keeps your hand clear of the mallet while driving, and also gives you more control of the split as you work your way down the log.
(7) I employed the Pythagorean Theorem (a*a + b*b = c*c ). See the end of the paper for a primer on how to use this.