Whole life costing: Carpets

Peter Mayer

The whole life costs of textile floor coverings
can be distinctly pricey for commercial and
domestic buildings. Peter Mayer of Building
LifePlans reviews the options.

Introduction


Whole-life costs of sheet or broadloom textile floor coverings can be high as they often need replacing and can cost a lot to clean. Factors to consider include: making sure the carpet system suits the substrate, the expected use and environment, maintenance and cleaning.

The classification of pile carpets is covered by BS EN 1037:2005. There are four domestic use classes, ranging from moderate/light to heavy, and three commercial use classes: moderate, general and heavy. Use classes are categorised by the carpet’s resistance to wear and change in appearance. EN 1307 also includes a luxury classification.

BS EN 13297 classifies needled pile floor coverings in a similar fashion, with three domestic and two commercial use classes.

Extra performance characteristics may be determined for demanding environments such those with caster chairs, as defined by the test standard BS EN 985, suitability for underfloor heating to ISO 6356, dimensional stability in intermittent humid conditions to ISO 2551 and use on stairs to EN 1963.

High-use locations such as airports may require tougher specifications.

Installation guidance can be found in the code of practice BS 5325 and the Contract Flooring Association Manual, as well as manufacturers’ guidance.

Underlays are important to improve comfort, insulation and expected life of the carpet. They may be fibrous, foam (rubber or polyurethane), rubber crumb or a combination of fibre and non-fibrous materials. BS EN 14499 defines minimum performance standards and BS 5808 defines a minimum requirement for compression.

Cleaning is critical to long–term performance. A British Standard Product Assessment Specification (PAS 86) for carpet cleaning is being developed. In the meantime, cleaning should be based on manufacturers’ guidance and the advice of specialist carpet cleaners.

Performance of textile floor coverings can be enhanced by use of entrance mats, multicoloured or patterned carpets to conceal dirt and positioning seams away from areas of high wear.

 


Sheet textile floor coverings


Cost and performance is not just related to use class but pile fibre, construction, colour, texture and design.


Natural fibres


The quality of 100% wool carpets is related to the length of pile, density of the yarn and tufts. These tend to be used in the luxury and domestic markets.

Other natural fibres are often specified for environmental reasons. Common materials include coir (coconut fibre), seagrass, jute and sisal. There are no BS specifications for these woven materials, apart from coir matting to which BS ISO 11861 refers. Performance data and use class descriptions may be provided by makers.

Sisal is the most hard-wearing and can be used for commercial applications. Coir is also hard-wearing but has a course finish so may not be desirable in commercial or public areas.

Seagrass and jute are typically used for domestic environments. Avoid seagrass on stairs as it contains natural oils.

 

Manmade fibres


Nylon or polyamide fibres can be produced in the full range of use classes with excellent wear performance. Nylon 6.6 is the best-performing type. Textiles can be engineered to provide enhanced performance such as easier cleaning or improved wear resistance. These claims should be confirmed from evidence in performance and test data.

Acrylic, polyester and polypropylene fibres are also used but do not give the same all-round performance as nylon

 

Wool-nylon mix


Typically 80% wool and 20% nylon carpets offer a compromise between the luxury of wool and the wear characteristics of nylon at a cost between the two. An 80–20 carpet will have better abrasive resistance than a 100% wool carpet and will perform better in very high traffic areas.

 

 

Specification options

 

Textile floor coverings Capital cost
£/m²
Net present value for 60 years£/m² Service life
Years
Domestic installations      
100% wool carpet to EN 1307 use class 23 for heavy use. 34 70 15 - 25
Jute floor covering for light use 23 70 10 - 15
Seagrass floor covering for moderate use 16 50 10 - 15
Commercial installations      
80% wool, 20% nylon EN 1307 33 heavy use; laid loose on underlay 29 520 10 - 20
80% wool, 20% nylon EN 1307 32 general use; laid loose on underlay 23 500 10 - 20
Nylon 6.6 floor covering, hessian backed, EN 1307 33 heavy use; laid loose on underlay 21 490 10 - 20
Sisal floor covering for moderate use; double stuck underlay 31 520 10 - 20

 

Table notes

• A discount rate of 3.5% is used to calculate net present values.

• Cleaning regime of daily vacuum cleaning, periodic intensive cleaning and an allowance for spot and stain removal is included in commercial examples. No allowance is made for cleaning for domestic use.

• All textile coverings laid on floors and include underlay and perimeter fixing. Costs are indicative average prices for plain textile coverings.

• A cost analysis based on project specific information is essential for a realistic best value appraisal.

First published in Building 2007

 

Further information


BLP provides latent defect warranties for buildings www.blpinsurance.com

Further information contact peter.mayer@blpinsurance.com or telephone: 020 7204 2450

 

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