What is the primary purpose of this test?

To evaluate the efficacy of fire-retardant treatments in slowing down the spread of flame on timber surfaces.

How is the timber classified after the test?

It is classified into distinct categories (e.g., Class 1 to 4) based on the maximum distance the flame spreads and the rate of that spread.

What are the standard dimensions for the test specimen?

The standard test specimen dimensions are typically 900 mm in length and 230 mm in width.

IS 4016 Part 2

: 1984

Methods of Test for Fire Retardant Properties of Treated Timber - Surface Spread of Flame Test

CurrentSpecializedTesting MethodFire Safety · Timber and Wood

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This standard specifies the testing method to determine the surface spread of flame characteristics of fire-retardant treated timber. It provides a classification system based on the distance and rate at which flames travel across the wood surface when exposed to a radiant heat source.

Specifies the procedure for conducting a surface spread of flame test to evaluate the fire retardant properties of treated timber.

Quick Reference Values

Conditioning temperature27 ± 2°C

Conditioning relative humidity65 ± 5%

Specimen length900 mm

Specimen width230 mm

Test observation duration10 minutes

Practical Notes

Ensure timber moisture content is properly conditioned (typically to equilibrium at 65% RH) before testing, as moisture significantly affects flame spread.

Do not confuse surface spread of flame with structural fire resistance; this test does not evaluate the load-bearing capacity of the timber under fire conditions.