Jasmin Cottage timber frame repair

Jasmin Cottage, Totnes. Early 19th century grade 2 listed with later extensions. Masonry ground floor and timber frame first floor. Investigation of cracks in external, portland, cement render below and around upper left window. 

In a meeting with the lime renderer, Lime Renovations, it is discussed that it would be better to plan for removing an 8'/2.4m strip of cement render, around the window and down to the overhang above the downstairs window. This should facilitate examination and repair of the timber frame and subsequent re-rendering in lime. Obviously, it would be better to be re-rendering the whole elevation in lime, but there are financial constraints for the owners. Making some of this wall more breathable is taking this building in the right direction. A conversation with South Hams Conservation agrees this course of action.

It would seem sensible to go slowly with removing the render, as we really have no idea what lies beneath. A heat sensitive camera has been used but that has revealed nothing about the timber frame; there are no differences in surface temperature, across the wall.

The cracks.

Keyhole surgery.

It becomes clearer why the heat camera is showing us nothing. There is render, EML expanded metal lath (badly corroded), then tar paper/sarking then battens, then the frame with tightly packed fibreglass insulation in between. Gypsum plasterboard on the inside; perfect conditions to rot the frame. That's a 3" screwdriver up to the hilt.

Oh dear, oh dear! Fortunate that Rivers Joinery are here.