Log
Dovetail
Jig Plans
How To
Lots of would-be cabin
builders contact me and inquire about building with no gap between the
logs (zero gap). Although this is definitely possible, it is generally
not recommended. Instead, I suggest that you use at least a 1/4" gap.
Having at least a minimal gap(with chinking) allows for the logs to settle while keeping the notches tight. Also, some logs are sure to shrink, twist or bow after some time. If there is no gap to begin with, gaps would open up in various places and it would be difficult to seal them. Chinking a gap of 1/4" or more is much easier than trying to fill alot of thin gaps here and there.
Generally, the gap size should be selected based on how much shrinkage/bowing/settling is anticipated. If your logs are fairly green then it is better to have a bigger gap in order to accomodate more movement. 1 1/2 inches would probably be about right in that case.
If the logs are kiln dried, resawn and then sealed, they should be very stable and a 1/4" gap should be fine.
Many cabins have fairly wide chinking and some people prefer that look. Gaps of 3-6 inches are not uncommon. A side benefit to using larger gaps is that it makes it easier to run wiring and mount electrical boxes.
A gap of 1/2" to 1" is generally good for chinking. The gap shown here is about 1 3/4". The larger the gap, the more expensive and time consuming it is to chink. I recommend using the modern flexible chinking products rather than mortar based. As the logs naturally move over time, the elastic sealant will maintain a good seal with no cracking.
Insert foam backer rod. The backer rod can be purchased in various diameters. It just needs to fit snugly. Recess it about 1/2". No need to nail it.
Apply the chinking (Log Jam, Perma Chink, etc.) using a caulk gun, bulk caulking gun or an air powered caulk gun. The standard caulk gun is really only practical for very small jobs and not recommended for a full cabin. (See the chinking product websites for more information).
Use a spray bottle to lightly moisten the chinking with water.
You can buy tools specifically made for smoothing out the chinking. Here, I am using a modified putty knife. It is pretty easy to spread and smooth the chinking. Be sure to force it against the wood along the top and bottom edges so it will form a good bond.
See the chinking product instructions for additional information.
_______________________________________________Unless the logs are very dry and sealed, it is recommended to frame openings in such a way as to allow the logs to settle without bearing on the frame. The following details show one method of framing openings. It is a good idea to use spacer blocks that are made from the same wood and that have a similar moisture content as the logs.