BS 9999 recommends for fire doors with cold smoke control that the threshold gap should be either less than 3mm in height or should be fitted with a threshold seal. When speaking with manufacturers, however, a common statement is that a fire doors gap of up to 8 mm underneath the door is permissible.

Do fire doors need a threshold?

Thresholds are not typically required by the codes and standards for fire door assemblies, although there may be a need for them when combustible floor coverings are used, depending on the critical radiant flux and the rating of the fire door assembly.

Can a fire door have a gap at the bottom?

Gaps between fire doors and the door frame should never be more than 4mm or less than 2mm. It's recommended to aim for a 3mm gap to ensure adequate room for the intumescent strips to activate in the event of a fire, and for the smoke seal strips (if installed) to not get damaged by the opening and closing of the door.

What are the legal requirements for a fire door?

Building regulations details where fire doors should be used:

• Any new build or home renovation that has three or more floors must have fire doors fitted to every habitable room that leads from a stairwell. ...
• Any door leading from your home into an integral garage must be a fire door.

What do you put on the bottom of a fire door?

In some circumstances, smoke seals are a Building Regulation requirement. Acoustic seals may also be required in certain situations such as in flats, apartments, doctor's surgeries and schools. These act to provide an additional role to reduce the sound which can travel between the door and frame, or door and floor.

What is the maximum gap under a door?

NFPA 80 currently allows a maximum bottom gap of 3/4 in. and a maximum of 1/8 in. for the perimeter (e.g. along vertical and top edges) of the swinging fire doors (with an additional 1/16 in. over-tolerance for steel doors).

Can you put a draft excluder on a fire door?

If your talking about putting a draft excluder on the bottom of the door then yes you could as this wouldn't compromise the fire door.

Do fire doors prevent the spread of smoke?

Fire doors have two important functions in a fire; when closed they form a barrier to stop the spread of fire and when opened they provide a means of escape. A well designed timber fire door will delay the spread of fire and smoke without causing too much hindrance to the movement of people and goods.

Do you need smoke seals on fire doors?

According to the British Standard 476 fire safety standards, most doors need to be S-type (smoke sealed) doors. Having a fireproof door installed with intumescent strips can help the door qualify for these standards. Seals need to limit leakage to a rate of 3 cubic metres of smoke through 1 metre of door edge per hour.

Should fire doors stop smoke?

Under-door (threshold) gaps should be in accordance with the manufacturer's installation instructions for the particular doorset design. If the fire door is required to stop cold smoke as well (FDs) it should be fitted with a threshold seal underneath the door to stop the smoke.

Should fire doors be airtight?

Fire doors are very effective at retaining fire for a period of time, and smoke seals fill their weak point, which is the space between the door and frame to ensure an airtight seal. Fire and smoke will travel through any gap to the air beyond, so it is important that fire doors have an effective seal at all times.

Do metal fire doors need intumescent strips?

Steel fire doors in steel frames with smoke seals (they do not require intumescent seals) are available, and such a replacement should not normally be an issue in respect of impact on the fire strategy.

Are fire doors a legal requirement in houses?

New build or renovated domestic properties which have 3 or more storeys (including loft conversions) must have fire doors to every habitable room off the stairwell.

Do fire doors need intumescent strips on the bottom?

In the event of a fire, without the intumescent strips, the door would not prevent the spread of fire for half as long, thus putting the residents or occupants of that building at much higher risk of injury and/or death. Fire doors play a crucial role in preventing the spread of fire and smoke.

Is it OK to paint over intumescent strips?

You can only over paint an intumescent strip which is designed for fire protection. You must not over paint a smoke seal. Also, be careful to ensure that the strip isn't damaged by the painter's preparations.

Can fire seals be painted?

Can you paint over smoke and fire seals? Painting over smoke seals will compromise smoke containment performance, however over painting fire seals should not compromise performance in a fire situation. The majority of our seals already come with a colour option so painting should not be a neccessary requirement.

How much clearance does a door need?

Tip. When measuring for a door, you should ideally leave at least 2 inches but maybe more like 2 1/2 or 3 inches. If you're using a door rough out, you should have a minimum of 3 inches.

Do all doors need to be fire doors?

If you're getting new interior doors and do not currently have fire doors fitted, standard doors are fine. You might want to consider fire doors anyway as a safety measure, but it's important to note that fire doors are thicker than standard doors and may not fit your existing door frames.

Do FD30 fire doors need intumescent strips?

The minimum rating of a fire door is now predominantly FD30, with intumescent seals being necessary to achieve this rating. This change came about in recognition that very tight edge gaps were necessary to achieve a FD20 fire rating when doors were subjected to fire resistance testing without intumescent strips.

Where do you put intumescent strips on a fire door?

Intumescent strips are generally fitted into the door frame but are sometimes into grooves in the door itself. If you don't have grooves in your fire door or frame, you can use a router to make a groove suitable for the intumescent strip.

How do you put intumescent strips on a fire door?

How To Fit An Intumescent Strip

1. Clean frame with damp cloth, removing dirt and grease.
2. Measure the height of the fire door, noting the position of the lock – and cut the smoke seal strip to fit accordingly.
3. Before using any adhesive, open and close the door with the seal in place.

Does a ground floor flat need a fire door?

Most flat units are of three or four storeys and will therefore require fire doors within the second and third floor flats. It is usual for builders to use the same doors throughout the other lower areas to avoid the incorrect fitting of non fire doors on the upper floors.

Are door closers required on flat doors?

Buildings housing flats will also require self-closing devices fitted to the front door of each flat, separating the flat entrance from the communal areas. In private dwelling houses, a self-closing device is only required if your home has an integral garage door.

What is the difference between smoke seals and intumescent strips?

What is the difference between a cold smoke seal and an intumescent strip? An intumescent strip expands when exposed to extreme heat, helping seal off gaps in between doors and door frames, to prevent the spread of fire. Smoke seals block smoke, and do not provide any protection against fire.