of fig1 and the base profile member 4 of fig2 in the fitted condition in this embodiment the thinnest possible stair covering 12 is used so that the abutment 20 comes to bear against the surface of the base profile member 4 the base profile member 4 and the tread angle member 1 may if necessary be produced in different sizes so that the assembly offers the optimum adjustment range for any stair covering 12 in this embodiment the stair edge assembly is used in conjunction with an inclined riser portion 32 reference will now be made to fig5 showing a further embodiment in which the guide support surfaces 6 and 7 referred to above and the corresponding co operating surfaces 8 and 9 are of a detent or retaining configuration in this embodiment the base profile member 4 has only one leg portion as indicated at 11 in this embodiment also no bore holes 15 are provided in the tread angle member 1 fig5 shows the fitting condition when the stair covering 12 used is of minimum thickness it will be appreciated that this construction can also be used when dealing with thicker stair coverings 12 fig6 is a view in cross section through an alternative form of the tread angle member 1 for the purposes of fixing the tread angle member 1.