Start With the Actual Wall

Our typical wall-panel log is around 14 inches in diameter. But diameter alone does not tell us the thermal resistance of a wall.

The important dimension is the amount of wood between the inside and outside surfaces of the finished wall.

This matters when comparing natural logs with milled logs. A milled log sold by nominal diameter may have material removed to create its finished profile, so its nominal diameter and its effective wall thickness are not necessarily the same thing.

Any useful comparison therefore starts with the actual cross-sections, not the names printed in a catalogue.

R-Value Needs Inputs

Wood does not have one universal R-value that can simply be multiplied by the diameter of every log.

Species, density, moisture content, direction and actual wall geometry all matter.

When we publish calculated values, the material properties, wall thickness and calculation method belong beside the result.

More Wood Between Inside and Outside

There is a simple physical reason we prefer substantial wall logs: more wood can mean greater thermal resistance through the wall.

It is one reason we typically work around 14 inches rather than trying to make the wall from smaller logs. Smaller logs also require more courses to reach the same wall height.

That does not give us permission to invent a percentage improvement. To compare two wall systems properly, we need their actual geometry and material properties.

In a Canadian winter, that is not a theoretical advantage. But it is still one we want to quantify properly.

Thermal Mass Is a Different Number

A substantial log wall also contains a substantial mass of wood. That mass can absorb and release heat over time.

Thermal mass is useful, but it is not insulation and should not be presented as though it were additional R-value.

We calculate and discuss the two separately.