Low Energy House

Low Energy House - Door Threshold Seals - Draught Proofing

Draughts account for much of the heat lost from dwellings. They also cause considerable discomfort to the occupants. It is good practice to fit threshold seals to the underside of external doors and to exclude draughts from other sources, such as letterboxes and keyholes

Weather Sealing Doors and Windows

Door Threshold Assembly Combining a Sealed Weather Bar and Weather Mould - Image Provided by SealmasterSealing doors and windows from the weather is more demanding than it may seem. Strong winds create ‘pressure drops’ at door and window positions, where the air pressure difference between inside and outside literally sucks water and cold air into the building or forces warm air to leak outside through any gaps and cracks.

Door Threshold Seal Assemblies

The most efficient door threshold assemblies combine a sealed weather bar fixed to the floor under the door with an aluminium or hardwood weather mould fitted onto the face of the door at low level.

There is a variety of door threshold assemblies to fit different door actions. The most common external doors are inward-opening single leaf doors but seals are also available for outward-opening single leaf doors, inward and outward opening double leaf doors and sliding doors.

Door Threshold Seals

A typical door threshold assembly consists of a compressed synthetic rubber tube insert fitted into a shallow extruded aluminium threshold bar. When the door is closed the rubber tube insert presses against the underside of the door to prevent draughts and water ingress. A matching extruded aluminium weather mould is fixed to the face of the door to shed the rain that runs down the door.

High Performance Door Threshold Assembly Combining a Sealed Weather Bar and Weather Mould - Image Provided by SealmasterHigh Performance Door Threshold Seals

For windy or driving rain conditions, the high performance door threshold assembly shown is constructed from an extruded aluminium threshold bar that is designed with an integral trough along its length. The trough is covered with a porous cover which keeps the rainwater in and the dirt out.

Two synthetic rubber blade seals project vertically down from the wood or aluminium weather mould and prevent draughts and water from entering the house.

When the door is opened, the secondary function of the blades is to wipe any surplus drops of water from the bottom of the door and direct them onto the porous cover of the collection trough. The trough collects all the surplus water and channels it to the outside through a series of drainage outlets in the base.

The drainage outlets are of a unique design and in stormy conditions, when gusts of wind attempt to force the air back through the drainage outlets, the outlets close until the pressure of water inside the collection trough rises and the drainage outlets reopen and enable the water to drain away. 

Door Threshold Seals

Compatible high performance door draught seals are available for use with high performance door threshold seals, in order to provide an airtight seal all around the door.

Wheeled Access Over Door Threshold Seals

Airtight and watertight door threshold seals are available in low profile format that reduce the likelihood of tripping and are accessible to wheeled traffic in compliance with Part M of the Building Regulations. 

If you are carrying out a comprehensive draught proofing scheme make sure you provide controllable ventilation to bathrooms, kitchens and laundry rooms to remove water vapour and prevent damaging condensation

About Door Threshold Seals - Door Draught Seals