Neil Sanders provides a full update on British Standard BS 8203
IN this month’s column, I’ll discuss the revised British Standard (BS) 8203:2017 installation of resilient floorcoverings code of practice, which has been modified to account for advances in materials and offer guidance and recommendations based on good working practice.
The latest version of the British Standard was published this year and supersedes the 2009 update (BS 8203:2001+A1:2009). The revision brings the standard in to line and up to date with the latest recommendations for plywood underlays and moisture management and aims to clear up grey areas for flooring contractors.
The update to BS 8203 specifically focuses on the recommendations for fabricated plywood underlays and was prepared under the authority of technical committee PRI/60, resilient and laminate floorcoverings.
The CFA produced a guidance note in 2013 to clarify the requirements of a flooring grade plywood that is suitable to receive a resilient floor covering. This has mostly been adopted by BS 8203:2017, under Annex A. Annex A clarifies which type of plywood is suitable for use as a fabricated underlay (ie overlays that can be used between a substrate and floor preparation materials).
The previous standard referred to weather and boil-proof (WBP) plywood as suitable for use as fabricated underlay. However, this type of plywood hasn’t been manufactured in the UK for over 10 years – WBP was part of a standard (BS 6566) which is now obsolete (withdrawn).
The revised standard refers to material that is suitable and available and is already being used by some flooring contractors.
Identifying flooring grade plywood
BS 8203:2017 recommends that flooring grade plywood should have a glue bond of Class 3 Exterior. Outer veneers are also recommended to be hardwood rather than softwood veneers and it’s important they’re at least 0.75mm thick and untreated.
The internal core quality of the plywood is also important as defects can telegraph through to the surface of the plywood.
The current required thickness of plywood is 6mm (nominal thickness 5.5mm ± 0.2mm) plywood.
The other major revision included in the new standard, and which makes up Annex B of the standard, is an update about hygrometer tests for dampness of concrete, cementitious and calcium sulphate bases.
Annex B supersedes Annex A. bringing BS 8203:2017 in line with the recommendations in BS 8201 code of practice for the installation of flooring of wood and wood-based panels, which was revised in 2011 and includes the hygrometer sleeve method.
Another major change to the standard is the introduction of a section 6.2.3 Surface Regularity which gives guidance on the degree of finish required before installing resilient floorcoverings.
The update of BS 8203 has been designed to produce a more robust standard code of practice for the contract flooring industry.
The standard now clarifies several grey areas that existed under the previous standard include several other modifications to bring BS8203 in line with changes to good working practice and to mirror the changes that have occurred within the industry since the standards last amendment in 2009.
IMAGE COPYRIGHT: JAMIE FLICKR