BEDS AND MATTRESSES – METHODS OF MEASUREMENT AND RECOMMENDED TOLERANCES

Up until the end of 1991, recommended size tolerances (nominal v actual) for beds were as specified in British Standards BS 1877 (Parts 1 and 9). The size tolerance recommended in that standard was ±30mm both for mattresses and divan bases, with respect to both width and length. Notwithstanding the standard's withdrawal at the end of 1991, the industry continued to adhere to its guideline on size tolerance.

A new approach to the subject arose in consequence of the publication of British Standard BS EN 1334:1996 – "Beds and mattresses – Methods of measurement and recommended tolerances" – which came into effect on 15 November 1996.

This standard (derived from an identical European Standard) was prepared in order to establish a method for the determination of the essential dimensions of mattresses, bed frames, divans and bed bases. Accordingly, the primary scope for the standard is to describe a method of measurement for determining such essential dimensions – and the standard is very specific and detailed (as it obviously needs to be) as to the conditions of test and the test equipment as well as to the method of measurement itself.

BS EN 1334:1996 has a secondary and subordinate purpose: it also includes recommended tolerances based on any nominal dimension, in order to ensure the correct fit between the bed components. It is essential to a proper understanding of the subject to appreciate that the tolerances mentioned in the standard amount to recommendations only: compliance with them is not compulsory. It is equally essential to understand that the recommended tolerances are only meaningful in the context of the standard’s provisions for "methods of measurement": no conclusion can be reached as to whether a product is within recommended size tolerances unless the method of measurement, exactly as described in the standard, has been carried out. As will be clear, it isn’t simply a question of "getting the tape measure out".

Against that background, the standard provides for the following recommended tolerances in nominal dimensions: -

Divan bases and mattresses to be placed on divan bases

• The tolerance on width and length for divan bases and mattresses to be placed on divan bases is ±20mm.
• The tolerance on height for divan bases is ±10mm.
• The tolerance on height for mattresses to be placed on divan bases is ±10mm or 10%, whichever is the lower.

Beds and bed bases

• The tolerance on the internal frame dimension of bedsteads and bed bases (ie the area into which the mattress is to be placed) is between -0mm and +5mm.

Bases and mattresses designed to fit into bed bases

• The tolerance on both length and width for mattresses designed to fit into bed base, is between +0mm and -20mm.
• The tolerance on height mattresses designed to fit into bed bases is ±10mm or 10% whichever is the lower.
• The tolerance on width for framed bases and framed sprung mattresses (ie those which are designed to be placed inside a bedstead or bed base) is between -5mm and -20mm.
• The tolerance on length for framed bases and framed sprung mattresses (ie those which are designed to be placed inside a bedstead or bed base) is between -10mm and -40mm.
• The tolerance on width for unframed slatted bases designed to be placed inside a bedstead or a bed base is between -5mm and -10mm.
• The tolerance on length for unframed slatted bases designed to be placed inside a bedstead or a bed base is between -10mm and -100mm. (The reason why the highest tolerance is as much as 100mm is that the first and last slats can be placed up to 50mm from both the head end and the foot end.)

NB: THIS PAPER DOES NOT PURPORT TO PROVIDE A COMPREHENSIVE SUMMARY OF BS EN 1334:1996, NOR IS IT HELD OUT THAT ITS CONTENTS ARE SIGNIFICANT IN ANY LEGAL CONTEXT. AN IN-DEPTH UNDERSTANDING NECESSITATES ACQUISITION AND STUDY OF THE STANDARD ITSELF.