Bridges for footpaths and bridleways can be supplied ready assembled, or in kit form. Either galvanised steel, timber or a combination of both. Timber beams can be specified as stress graded, as well as specific species. Douglas fir is preferred as a main structural timber and can be supplied tanalised or untreated. Larch is often used for handrail construction and again can be treated or not. Steel can be used to increase the length and capacity of a bridge and can be shaped to reduce section size. If clad afterwards, it can be hard to detect the steel at all.