SR27 Draught control systems for New Zealand houses (1990)

This paper examines the role that draught seals can play in the opening joints of doors and opening windows and suggests levels of performance that should be achieved. Draught seals need to be extremely easily compressible to avoid excessive closing forces.

Many of the systems available were found to be too stiff to cope with varying sized gap widths around a warped door. Of the seals available for retrofit application, only one generic type was sufficiently tolerant of varying gap width. Most of the materials were found to be adequately airtight.

Threshold seals on external doors have to resist rain and air penetration as well as being mechanically robust and resistant to sunlight. In consequence, they tend to be more complicated and bulky than perimeter strips. Most threshold seals were found to achieve adequate airtightness but few were found to separate the air sealing and rain screen functions necessary for optimum protection against rain.