Sleepy Goose Farm

It’s time to demo the guest room-to-be! The coolest part of opening up walls and ceilings is seeing all of the vintage ways in which this old part of the house was put together.

Those thin wood strips are called ‘lath’. The lath and plaster technique was generally used to finish interior walls and ceilings from the 1700s to the early-to-mid 1900s before it was superseded by modern gypsum plaster and plasterboard.

Laths or ‘lathes’ are narrow strips of timber nailed horizontally across the timber stud frame or ceiling joists and then coated in plaster to finish the wall surface. The technique derives from a more basic historical building method called wattle and daub that’s been used for at least 6000 years.

Laths can be sawn or riven (split) with the latter providing greater strength and durability due to the split along the natural grain of the wood. Hardwoods are commonly used such as oak, chestnut and larch.

The measured spacing is critical and allows plaster to be pushed or squeezed through and behind the laths locking the plaster to the wall as it sets – these ‘curls’ of plaster are known as keys and they play a vital mechanical role in securing the plaster to the wall. Traditionally, lime plaster was mixed with coarse animal hair such as horse or goat hair to reinforce the plasterwork, thereby helping to prevent the keys from breaking away. ‘Haired lime’ also allowed greater flexibility in the lime and helped prevent cracking.

Though there were advantages to the lath and plaster technique – it more easily allowed for ornamental or decorative shapes, provided sound insulation and helped to slow fire spread – new materials superseded lath and plaster because they were simply faster and less expensive to install.

Lath and plaster was a skilled craft and a time-consuming technique and the advent of cheaper, mass produced, pre-manufactured plasterboard meant lath and plaster largely fell out of favour by the 1930s and 1940s. Plasterboard was simply faster and less expensive to install.

We found out we have a chestnut tree! 🐿🌰