A bulkhead assembly for a wind turbine blade is described, where the bulkhead is substantially formed from a flexible sheet material. In one aspect, the flexible sheet material can be attached to the larger assembly using a releasable connection, e.g. a zipped connection, to allow for relatively easy installation and removal, e.g. for repair or other service operations. At least a portion of the sheet material may be transparent, to allow for easy inspection of the interior of the wind turbine blade. In one aspect, the bulkhead assembly is arranged to couple to, or is formed integrally with, the root flange of a wind turbine blade. The use of such a flexible material to form the blade root end bulkhead allows for ease of handling and manufacturability over prior art systems.