Timber Frame Storey & Hand-Cut Roof

Where an upper storey is set back from the main elevation, timber frame is often the better answer than masonry. It goes up faster at height, it weighs far less on the structure below, and it takes a deeper insulation zone in the same wall thickness.

On this Kent property the clients wanted the new top floor to feel nothing like the cramped roof space it replaced: generous head height, a vaulted ceiling over the main room, and a roof line redesigned around the new layout rather than inherited from the old one. That ruled out standard trussed rafters, which fix the shape of the space before you have chosen it.

The upper storey was framed in treated softwood, sheathed in OSB for racking strength and wrapped in DuPont Tyvek housewrap, a BBA-certified breather membrane that keeps wind and rain out while still letting the structure release moisture. Joints were lapped and taped in the right order so water is always shed outward, and openings were dressed properly rather than simply cut through.

Our carpenters then cut the roof on site. Cutting a roof by hand takes longer than craning in trusses, but it is the only way to get hips, valleys and a vaulted section in the same structure, and it lets the ceiling line follow the room rather than the other way round. Ridge, hips and jack rafters were set out and cut on site, with a structural ridge and purlins carrying the vaulted span.

Internal stud partitions were then set out to the new layout, ready for first fix. The whole storey was built under a scaffold with a temporary roof over it, so the existing roof could be stripped and the new structure cut without the house ever being open to the weather.