Abstract: When hospital mattresses are to be disinfected or washed, measures must be taken to prevent the washing water from penetrating through the cover to the mattress. These special measures to make closures in the form of e.g. zippers, button closures or snap closures liquid-tight, may be tape or the like. To avoid these difficulties and drawbacks, the closure according to the invention may be constructed as a strip (9), which may be secured directly to the cover (3). Then, the strip (9) and the cover (3) may be cut to form an opening (8) through which the mattress (1) may be inserted. The subsequent closing takes place by means of a slidable strip (6) which may he applied and locked to the first strip (9). The strips (6, 9) are welded together at the ends to form an end closure (7). This results in a strong and liquid-tight closure so that the mattress may be washed/cleaned in a washing machine.