What is an owl board?

An owl board is a small triangular board with a round hole in it, fitted at the apex of a roof where the ridge meets the hip rafters. In Dutch it is called an ‘uilenbord’. It is typical of thatched farmhouses in the northern and eastern Netherlands: Friesland, Groningen, Drenthe and Twente. The hole, the owl hole, gave barn owls and little owls a way in and out of the loft.

Purpose

• Access for owls: farmers welcomed owls because they kept mice and rats away from stored hay and grain.
• Protecting the ridge: the board covers the vulnerable end of the ridge, so rain cannot drive into the thatch and the ridge timbers.
• Air and light: the opening lets a little air and daylight into the top of the roof. Some boards have a small window instead of an open hole.

Shape and decoration

A vertical post usually runs up the centre of the board. In Friesland, two cut-out swan necks typically lean against it. Motifs vary by region: swans, a chalice, ears of wheat or a harp. Most owl boards are timber, sometimes carved; modern versions also come in sheet material or solid plastic, which need less maintenance.

Application

• Thatched roofs with a hipped or half-hipped end, where the board closes the apex between the roof slopes.
• Restoration of historic farmhouses, where the regional motif strongly defines the character.

Tips and points of attention

• Keep the hole open if you want to help owls. Mesh or glazing keeps birds out but defeats the purpose.
• End grain and carving soak up water. Check paint and joints regularly, as rot in the board can spread to the ridge structure.
• Weathertight junction: the joint between board and thatch must shed water. When replacing a board, have a thatcher assess the detail.
• Listed buildings: on a protected farmhouse, swapping the board for a different design or material may need consent. Ask the local authority first.
• Nesting season: owls are protected species in many countries. Plan work on an occupied board outside the breeding season.

Related terms

• Thatching
• Roof ridge
• Thatch ridge tile
• Hip rafter
• Gable finial
• Farmhouse

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