8. Detailed Instructions – First Full Round

Feb 08, 2021


First Full Round

If you’re working offline (in the forest), you can download the instructions here: Lesson 8 First Full Round

First Full Logs – Round 1

Be sure to watch video 8 in this module in order to reference these notes.

Let’s take a look at the process used to lay our first full logs. Set the pre selected, next logs in place on the receivers. Ensure that there are at least 2 inches of trim beyond the building dimensions at each end, then proceed to mark and trim the logs to rough length. With the logs in place and trimmed:

  1. carry on with the remaining steps of our 10 steps to Laying a Dovetail Log, listed in Lesson 6.
  2. equalize the log. This is the only step that is slightly different on the first round than on the remaining wall logs. Instead of equalizing the height to the top of the log, on the first round you must equalize the gap between the underside of our log and the subfloor. To ensure tight fitting notches, the log must be let straight down an equal amount on each end. Therefore, if we want to have a good seal between the underside of our first log and the subfloor, we must equalize so that the gap runs evenly along its length.


*Note: On first full logs, set your scribe setting so it is a ¼” less than the gap between underside of first log and subfloor (or temporary blocks). This will give you a little grace on your first tails should you need to touch them up. As well, the ¼” remaining under the log will quickly disappear once the logs dry slightly and the added weight of additional rounds above compresses the fibers.*


  1. with the log now equalized to the underside and the scribe setting found, continue with the remaining steps to the scribe the first connectors. Review Lesson 6 for a reminder of the connector scribing steps. Once the scribing is complete, do not flop the logs down on the half rounds, as the forces may cause things to bounce or shift. Instead, lift the logs off and roll them over to cut notches.
  2. cut the connectors following the steps described in Lesson 6.

Before returning the logs to the wall, peel the wane on the top side edges of the half round and the first round. Do not peel the wane onto the underside of the first round as it contacts the subfloor and there is no chinking. See Lesson 9 for a description of how and why we wane our logs and watch the accompanying video 9 for a demonstration on how to wane the log.


The goal is to have crisp corners on the underside of the first round where it meets the floor.


Check the Final Fit Once the connectors are cut, place the logs back on the half log receivers. Do so with caution so as not to bump any of the previous layout out of line. When you are inspecting the fit of the dovetails there are two main details to consider. Firstly, ensure that once notched down, the log is still sitting plumb. This can be quickly checked by referencing the plumb lines drawn on the end grain of the logs during the pre scribe line up. Next, inspect the two mating faces. The joint where the two logs contact each other should be crisp and flat, with even contact across the visible surfaces.

If there are any corrections that need to be made to improve either of these factors do so with the small grinder. The log is lifted off the receivers, moved so that it is not hanging above the work zone and the modifications are done only to the receiver face. We only work the receiver because this means we don’t have to set the upper log down and roll it over each time. Sometimes you get a stubborn tail that seems to have a mind of its own and just doesn’t want to sit quite right. Be patient and work it until the fit is exact. It’s going to be there for a few hundred years so you might as well take the extra few minutes to make it perfect.



Check the Building Width Each time we lay a pair of logs, it is important that we check our building widths from outside face to outside face on all four walls. If our scribed length between the shoulders on the interior face of the log is slightly long, this will spread the two lower perpendicular logs slightly apart as the new log is wedged between.

If the measurement reads a hair long then the appropriate amount of wood will need to be removed from one of the shoulders so that the logs will have room to return to their required location. Remember that if you have to shave the interior shoulder to let the log creep in, you may have to do the same to the exterior chinking set back to maintain the desired 3/8” gap. If the building width shows narrow when measured at either end of the most recent pair of logs fitted, it means the receiver was laid out a little too long or the shoulder was slightly over cut. If this is the case, we typically leave it and correct with the next pair of logs (assuming it is minor).

Before we can make the required width correction, we need to fit the next 2 perpendicular logs. Therefore, we make a note on the end grain of the appropriate log stating the required adjustment so that it will be noticed and remembered when we work our way back to this point.

Seat the Log Once you are satisfied (and hopefully excited) with the fit of the log, the final step is to ‘seat’ the log. This is simply giving it a couple of good downward whacks with the sledge hammer at each end. If you do the hammering where the next receivers will be cut then you don’t need to worry about the divots created as they will disappear with the waste wood of the receiver.


  • Do not cut through the bottom log of door openings, until the building has been moved and set up on final the foundation. Maintaining full length logs will aid in more efficient and accurate lining up and squaring of the first round.


Installing the First Round to the Subfloor or Foundation.

If you are building directly on the subfloor or when you do the final set up on your subfloor you will need to attach the first round of logs securely to the wood or concrete. If you are building on a wooden subfloor the simplest solution is to use timber screws. These self tapping screws drive easily and have incredible downward holding power. They are readily available in lengths up to 24”. If you are installing the logs on a concrete foundation or curb wall, you will have to use concrete anchors with a threaded rod installed.

It is recommended that you fasten the log along its length at a minimum of every 6’. An anchor should be placed within 8”-12” on either side of a door opening. Local codes or authorities may require different specifications.



A spacer board is used to create a slot suitable to tuck the finished flooring under the first round of logs. This creates a much cleaner finish than scribing the floor boards to the logs, and negates the need for base board trim. Use a spacer material that matches the thickness of the flooring material to be used. The spacer should be approximately 1” narrower than the logs in order to create the appropriate tuck space.

It is good practice to install a flashing on the subfloor edge before the logs are placed. This will help direct moisture away from the log to the floor mating point. A foam sill gasket should be placed between the subfloor and the first round of logs to seal up the junction. If you are building directly on the subfloor be sure to reference the Electrical Lesson in Video 19 before adding anymore logs to the wall.


If you’re working offline (in the forest), you can download the instructions here: Lesson 8 First Full Round