Specifying a floor covering for a commercial application requires at least a cursory understanding of how it will perform in the workplace. Unfortunately, marks like “contract quality” or “heavy domestic” are open to interpretation, making it difficult for the specifier to make an informed decision. decision.
Simon Lawrence of UK carpet tile specialist Bürofloor gives an insight into the standard tests that can be applied to carpets that are required to perform, and last, in the harsh commercial environment.
Commercial premises place high performance requirements on any type of floor covering. When coffee goes bad at home, there’s an immediate rush of scrubbing and spraying with stain remover. In the workplace you are more likely to be ignored and then stepped on with unclean outdoor shoes. Your sofa at home moves when you need to remove the dust or the small toys from under it. The beaver chairs in his office travel for miles, punching holes in the carpet tiles as they do so.
This means that we need a benchmark by which we can judge the suitability of the carpet or carpet tiles for use in commercial contracts. Fortunately, standardized tests exist to provide Euronorm (EN) and International Organization for Standardization (ISO) certification. Genuine heavy contract products must meet the standards outlined here.
ISO 8543 – Effective weight of the stack
Carpet tiles need a dense, closely packed pile to provide the necessary wear resistance. To provide a standard for this, ISO 8543 specifies a method of shaving carpet down to the backing. Simply measure the mass of the pile removed in grams per square meter. In general, the higher the pile mass, the stronger the carpet tile.
ISO 1765 – Total thickness
This is another relatively simple test. In this case, the carpet tile is compressed with a standard weight and then its thickness is measured to the nearest 0.1mm.
EN 1963 – Lisson treadmill test
This test measures the carpet’s resistance to scratching, with particular emphasis on the strength with which tufts of hair are secured. The treadmill is placed on the mat to be tested and rolled back and forth over the sample 400 times. The wheel spins slightly faster than it moves across the carpet creating a harsh scratch effect. The tested carpet sample is compared to the master samples and graded accordingly. This is a particularly aggressive test, literally ripping some types of carpet tiles to pieces. A pass under EN1963 is a strong indicator of good wear resistance.
ISO 10361 – Accelerated wear test
This standard is especially relevant for carpet tiles that will be used in an office. It is made up of two tests, the Vetterman Drum Test and the Beaver Saddle Test.
Vetterman drum test
The Vetterman Drum Test is designed to simulate strong, focused stomps. Foot traffic tends to concentrate around doorways or narrow passageways between desks, and these areas can quickly become threadbare.
The test mat is fixed inside a rotating metal drum. A heavy ball (7.5 kg), covered with hard rubber bumps, is placed inside the drum and allowed to bounce freely. The mat is put through two test programs, one of 5,000 drum rotations and one of 22,000 rotations.
The carpet is then visually compared to master wear samples and given a rating of how well it has withstood the effects of the test.
Visual inspections of the mat give results from 1 to 5 for 5,000 and 22,000 rotations and the final result is a combination of the two results according to the formula below;
Total result = 0.75 x Result after 5,000 spins + 0.25 x Result after 22,000 spins
A result of 2 or more is a pass
A result of 2.4 or more is a pass for intensive use
beaver chair test
Wheelchairs are particularly damaging, and the uneven holes they use in floor coverings can pose a tripping hazard. The results of this test should be an essential part of the office carpet specification.
The test team rolls a three-wheeled chair, weighing 90 kg, on the carpet. Two samples are used, one run for 5,000 cycles and one for 25,000 cycles.
The tested samples are visually evaluated against standard samples and scored on a scale of 1 to 5. The final test result is given according to the following formula;
Total result = 0.75 x Result after 5,000 rotations + 0.25 x Result after 25,000 rotations
ISO/DIS 10965 – Electrical resistance
This test is particularly important for contract mats that could well be found in computer rooms where the buildup of static electricity could damage valuable equipment.
The carpet sample to be tested must be acclimatized for at least 7 days prior to testing at a temperature of 23+/-1°C and 25+/-2% relative humidity. This is because humidity has a great impact on the conductivity of textiles and must be rigorously controlled to obtain a meaningful test.
In this test regime, the horizontal resistance and vertical resistance of the mat (in ohms) are measured.
Horizontal Strength: An insulating base is placed under the carpet tile sample that is to be stacked up. Two electrodes are connected to the tile 200 mm apart and the resistance in ohms between them is measured.
Vertical resistance: Here the electrodes are above and below the carpet tile and the resistance in ohms between them is measured.
For computer rooms, measurements below 1010 ohms are necessary.
ISO 3415 – Static load (compression test)
This test is designed to see how much the mat compresses with a weight placed on it. Reproduces the effect of furniture on the carpet.
The thickness is measured before compression.
A pressure of 220 kPa is applied for 15, 30 and 60 minutes.
The result is simply given in thickness loss in mm after
a recovery period of 1 hour.
Acoustic properties ISO 140-8
The test equipment for this standard consists of two spaces, one above the other, and 5 hammers, each 500 gr. The first test is to measure shock absorption, i.e. how much impact noise the carpet sample absorbs.
First, the hammers are allowed to fall freely onto the floor of the headspace from a height of 4 cm, each hitting the ground 10 times per second. The noise in decibels is recorded in the space below.
The test is then repeated with the addition of the sample carpet to the floor of the overhead space.
The difference in decibels is the amount of impact noise the carpet sample has absorbed. This test is interesting because it shows how well carpet works at stopping noise transmission compared to other floor coverings like wood or vinyl.
For ISO 354 the absorption of ambient noise is measured. noise of different frequencies; (125 – 250 – 500 – 1000 – 2000) are transmitted to a 200 m³ room and the amount of noise that bounces off the floor is measured. This is then compared to the noise reflected from the floor when covered with sample material. A result of 0.5 in this test shows that 50% of the noise that would have been reflected was absorbed by the test sample and the remaining 50% was reflected by it.
ISO 2551 – Dimensional stability and EN 986 for tiles
Carpet tiles must maintain their dimensions ±0.02% after the following treatments:
Heating at a temperature of 60°C for 2 hours
Bath in water at a temperature of 20°C for 2 hours
Additional heating at a temperature of 60°C for 24 hours
Conditioning under normal atmospheric conditions for 48 hours
These treatments prove that the tiles will retain their integrity under the harshest conditions, such as hot water cleaning and extreme temperatures.
cost of ownership
All floor coverings carry a hidden expense in the form of replacement costs. In commercial premises, this cost is further increased by the business interruption of installing new carpet tiles. Buying recklessly will inevitably lead to more spending. A trusted provider must respond positively to a request for test data. We hope the information in this article helps make sense of the test specifications and supports an informed choice.