If considering a Coburn Foldaside 100 top hanging sliding folding gear in a situation where a bottom guide rail cannot be used, as the underlying floor is concrete and the 15mm groove in to which to set the bottom guide could not be provided. The manufacturer’s guidelines are that “The floor guide and channel must be used on doors over 15kg or 450mm wide.” The reason is that the floor guide takes most of the lateral load off the hinges, and hinges supplied with the kits are only lightweight. It might be an idea to look at the more heavy duty Saheco SF-A84D sliding-folding system, because we supply that with Royde & Tucker H102 or H104 Hi Load hinges. Alternatively Hi-load hinges can be purchased separately, which would mean you would almost certainly be successful without the bottom guide.