Duffield Timber supplied Thermo-Ayous cladding in our vertical shadow gap profile (DTC15), factory-coated in Chartex® Coal Black and Colourflex® Natural, for Floya, a prefabricated mobile home by North Yorkshire builder Happynest Homes.

Happynest Homes is a North Yorkshire company, based near York, that builds small prefabricated homes, annexes and guest cabins on wheeled chassis. Its homes are built to exceed BS 3632:2023, the British standard for residential mobile homes, with airtight construction, mechanical ventilation with heat recovery (MVHR) and passive solar design.

Upper corner of a wooden-clad roof with vertical brown panels, dark metal trim, and a small white geometric vent against a clear blue sky.

We visited Linda and Rob at Happynest to see Floya, their latest build. Happynest builds near York and our mill is at Melmerby, so the cladding had only a short trip between two North Yorkshire businesses.

The exterior is clad in Thermo-Ayous in two finishes, Chartex® Coal Black and Colourflex® Natural. Both were factory-applied at our mill before delivery.

Exterior of a modern building with vertical wooden panels, large glass doors, two black wall lanterns, and a green tree in the background.

The boards were machined to our vertical shadow gap secret nail profile (DTC15) at 18 x 144mm with a 128mm cover. Fitted vertically, each joint forms a 10mm shadow gap, and because the boards are secret-nailed, no fixings show once they’re installed.

Sunlit wooden deck with vertical railing slats casting long shadows across the floorboards.

For the Chartex® finish, the grain is wire-brushed to bring out its texture, then coated in a Coal Black wood stain, giving a charred-effect finish without burning the timber. Colourflex® Natural is a matt, non-film-forming stain that penetrates the timber and filters UV, helping the Thermo-Ayous keep its warm brown colour, with a service life of up to five years before first maintenance.

Modern dark wooden tiny house with large glass windows, an angled roof with exposed wooden beams, and a blue-sky backdrop with trees.

Thermo-Ayous is ayous (Triplochiton scleroxylon), a West and Central African hardwood, thermally modified with heat in a controlled atmosphere and no chemicals. It is a clear-grade, virtually knot-free board, and the modification raises it to Durability Class 1 and improves its dimensional stability.

At around 400kg/m³, it is also light for a hardwood. That’s useful on a home built on a wheeled chassis and delivered by low-loader.