Astroflame Passive Fire Protection Products

Trade Name: Astro FRA Socket Box Insert

A Putty Pad alternative -
Fire Rated & Acoustic Internal Socket Box Insert

Easy to install putty pad alternative.

Single and Double socket sizes available.

Tested to BS EN 1363-1 | BS EN 1364-1 for up to 120 mins.

Provides an effective acoustic barrier to both impact and airborne sounds.

Maintains the fire protection performance of the wall- preventing or delaying the spread of fire.

Prevents or delays fire from entering a wall cavity and attacking the building structure.

The inserts are pre-formed to fit all common socket box types.

Simple and fast mechanical fixing, no adhesives, no mess.

Can be retro fitted to existing sockets / switches or fitted during wall construction.

Replaces time consuming plasterboard lining of sockets / switches

The Socket box insert can be removed and replaced if additional wiring is required.

Unique flanged design holds the socket box insert in place during a fire

Acoustic Tested to BS EN ISO 140-3: 1995 and BS EN ISO 717-1: 1997

Intumescent Mastic at Astroflame - in various colours

View a range of styles

>> See more : Additional product images

>> Call us to order: 01329 844 500

>> Email us to order:

Socket Box Insert Dimensions


Socket Box Inserts are used to restore the fire rating of a wall otherwise compromised by apertures and gaps following the fitting of socket boxes. This design also restores the acoustic and thermal performance of the wall and its air-tightness.

Inserts are quick and easy to fit in comparison with traditional putty pads.

Once a hole is made in the wall for a recessed switch or socket box, the integrity of the construction and its ability to perform in a fire can be significantly reduced. The acoustic performance of the wall is also affected and air leakage will increase.

Air leakage rates with and without socket inserts.Air leakage allows heat loss and noise transmission. A single socket can leak over 3.5 cubic metres of air per hour and the combined air leakage of all the sockets in a room can create significant thermal loss.

The graph opposite show how our socket box inserts improve air-tightness at normal room air pressures. A correctly fitted insert can almost match the performance of an unpenetrated wall.

The material used to construct the socket insert is a good insulator, which further prevents heat loss and maintain insulation continuity of the wall.

Acoustic performance is good, being rated at -67dB

The socket box inserts are quicker and easier to fit that traditional putty pads. In a fire the inserts flanged design ensures that the fire resistant material remains in place to limit the spread of fire through the socket penetration.

Astro FRA Socket Box Inserts are designed to fit common plastic / metal single / double socket box sizes.

Click on the images below to view the Socket Box Insert measurements (in mm):

A 35mm Deep Double Socket Box Insert Product
A 47mm Deep Double Socket Box Insert Product
A 35mm Deep Single Socket Box Insert Product
A 47mm Deep Single Socket Box Insert Product

Double Socket Box Insert 35mm Deep

Double Socket Box Insert 47mm Deep

Single Socket Box Insert 35mm Deep

Single Socket Box Insert 47mm Deep

Product Availability

Single or Double Socket sizes supplied as one per box or in boxes of 10 per size.

Available in:-
Standard Depth - 35mm deep
or Extra Deep - 47mm deep

Product Code

Product Description



Astro FRA Socket Box Insert Single



Astro FRA Socket Box Insert Double



Astro FRA Socket Box Insert Single Extra Deep



Astro FRA Socket Box Insert Double Extra Deep


To order & specify

Please contact us and quote the following information - Please quote- Quantity / Product Ref / Trade name / Size
Typical wording- 10 / AFFRASOCSIN / Astro FRA Socket Box Insert Single / 35mm

>> Tel: 01329 844 500 or >> Email:


For further information on installation requirements please see the installation video or contact the technical team on: tel 01329 844 500 or email

Health and Safety

The product does not present any known health hazards during or after installation. Normal good industrial and personal hygiene practices should be observed. For further information on health and safety requirements please see the (SDS) Safety Data sheet or contact the technical team on: tel 01329 844 500 or email

Fire Test and Assessment Reports

Fire tested to BS EN 1363-1 | 1364-1 for up to 120 mins.

Acoustic tested BS EN ISO 140-3:1995 and BS EN ISO 717-1:1997

Air leakage tested to BS EN 1026:2000 over a pressure range of 2-50 Pa.


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As part of our policy of ongoing improvements, we reserve the right to modify, alter or change product specifications without giving notice. Product illustrations are representations only. All information contained in this document is provided for guidance only, and as ASTROFLAME FIRESEALS LTD has no control over the installation methods of the products, or of the prevailing site conditions, no warranties expressed or implied are intended to be given as to the actual performance of the products mentioned or referred to, and no liability whatsoever will be accepted for any loss, damage or injury arising from the use of the information given of products mentioned or referred to herein.

The above information to the best of our knowledge is true and accurate and based upon current test data and is supplied for your guidance only. Customers should satisfy themselves to the suitability of the product in its intended use and no guarantee is given or implied since the conditions of actual use are beyond our control. ASTROflame (Fireseals) Ltd, disclaim any liability for loss, damage or other expense arising from the use of information, data or products mentioned or referred to and reserve the right to change any details or specifications without notice.


Astroflame (Fire Seals) Ltd. Intumescent House
Unit 8, The IO Centre, Stephenson Road, Segensworth
tel 0800 023 2482
(01329 844500)
fax 0800 023 2483
(01329 844600)
tel +44 1329 844500
fax +44 1329 844600



Email Astroflame