How our log wall system works

Each course of wall is a solid Nordic timber log of 44–70 mm, machined with a tongue-and-groove profile on its upper and lower faces and notched at the corners so walls lock into each other. Courses stack and seat together, and the corner notching is what gives the building its racking strength against wind.

Because the profiles are cut in the factory to tight tolerances, the fit is tight without relying on sealant to make up the difference. That matters in a wind-driven-rain climate: a gap that is filled rather than fitted is a gap that will open again.

This is the part that surprises people coming from block construction. Solid timber takes up and gives off moisture with the seasons, so a log wall expands and contracts slightly across the year, and settles a little in its first couple of years as the timber reaches equilibrium.

This is normal and it is designed for. Door and window openings are detailed so the joinery is not pinched as the wall settles, and fixings at the wall head allow for movement rather than locking it. What it does mean is that you should not rigidly fix anything tall and unyielding — a full-height fitted unit, say — hard between a log wall and the ceiling without allowing for the movement.

Floor and roof insulation are standard on every model. The walls are where you make a decision, and the honest answer depends on how you will use the building rather than on what we would prefer to sell.

A room used in daylight through spring, summer and autumn — a studio, a workshop, a summer room — performs perfectly well on the log wall alone. A building used daily through the winter, or used for sleeping, or heated continuously, is a different case: there the optional double wall insulation kit, which adds extruded polystyrene in the walls and floor, pays for itself in running costs and comfort.

Left bare, the interior face of a log wall is a finished surface — it is the same milled timber, and most customers simply treat it. That is the cheapest and fastest route and it is why the shell version is viable for people who want to do their own fit-out.

If you want painted flat walls instead, the insulation kit gives you the service void and substrate to line and finish conventionally. Either way, leave the wall able to breathe: sealing a log wall behind an impermeable layer traps moisture in the exact place you do not want it.