Low Energy House - Door Draught Seals - Door Seals

Fitting draught proof seals to the gaps around external doors will improve thermal comfort and reduce heating bills. Draught excluder seals are manufactured in a variety of profiles and lengths and are fitted to the sides and top of the door frame

Fitting Door Draught Seals

Sealing 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.

Typical Air Leakage Around Doors

A typical unsealed single leaf external door has a gap of approximately 2mm, between the door style and the door frame. At the threshold, it has a gap of 6mm and quite often there is no water bar. The air leakage effect of this is equivalent to a circular hole in a standard door of 139mm diameter or a square aperture of 4.84 by 4.84 inches. Many doors are misaligned with larger gaps than in this example. In general terms, an unsealed single leaf external door has gaps equivalent to or greater than a permanently open letter plate.

In a double door assembly, assuming a 2mm gap around each door and a 6mm gap at the threshold, the air leakage is equivalent to a circular hole of 183mm diameter or a square aperture of 6.36 by 6.36 inches. As the result of misalignment, a double door will have gaps equivalent to, or greater than, a permanently open cat flap.

Door Seals for All Door Actions

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

Weather Strip Draught Seals

Weather strip seals are available in a variety of designs for use on existing doors. In their basic form they are seals fixed into plastic or aluminium holders which can be fixed to the sides and top of door or window frames. These are relatively straight forward to fix and are popular for DIY applications.

Brush Strip Seal

Brush strip draught seals are suitable for use on external doors which have irregular gaps that are difficult to seal. Lighter types consist of siliconised nylon pile in self adhesive strips. More robust types comprise strips of nylon or polypropylene bristles fitted into a metal or plastic holder which is fixed directly to the door frame. Brush seals are suitable for sliding patio doors and single leaf external doors that open inwards or outwards.

Flexible Tube Strip Seal

Flexible tube strip seals suitable for external doors are generally in the form of small diameter synthetic rubber tube, held in a plastic or metal holder, which is fixed directly to the door frame. When the door is closed the tube compresses to close the gap between the door and the frame.

Flexible Blade Strip Seal

Blade strip seals are suitable for use on external doors with irregular gaps that are difficult to seal with some types of excluder. They consist of a flat strip of synthetic rubber, shaped like a car windscreen wiper, that is fitted into a metal or plastic holder and fixed directly to the door frame. Blade strip seals are suitable for sliding patio doors and single leaf external doors that open inwards or outwards.

High Performance Door Seals

High performance door seals, as the name suggests, are much more efficient and constitute better value for money in the long term. High performance seals are designed in two parts and are suitable for new and existing doors. The holder which accommodates the basic seal section is screw fixed to the surface of the door frame. The screw fixings are then hidden by the cover section which is available in a choice of designs and finishes to suit the door design and to match the draught proof threshold section.

Single Leaf Door Draught Seals

Surface mounted door draught seals with concealed fixings are available for inward or outward opening single leaf doors. They are fitted onto the jambs and heads of door frames and can be used in conjunction with door threshold seals to provide high performance draught proofing. The door seal assemblies can be butt jointed or mitred at the the corners.

External Double Doors Draught Seals

High performance door draught seals are also specified for use on double doors with rebated meeting styles. These are primarily for french doors or other situations where the door leaves close flush. These draught seals are used in conjunction with other door frame and threshold seals where control of air leakage is important.

Door Threshold Seals

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

Draught Seals for Windows

Window seals are generally produced in smaller section sizes and most of the door seal types shown can be used for draught proofing windows. These seals are generally most appropriate for use on single action casement windows.

If a comprehensive draught proofing scheme is being carried out it is important to make sure controllable ventilation is provided in bathrooms, kitchens and laundry rooms to remove water vapour and prevent damaging condensation