The construction of the arch begins with attachment to the ceiling and walls with pine boards section 40×40 mm. Length of the beams 300 – 400 mm, edges cut down at an angle of 45°. To the pinned in the corner of the parallel bars with screws attached another beam with the same cross section (40×40 mm) and a length of 500 – 600 mm. To the hypotenuse thus obtained triangular frame are attached to hardboard with a thickness of 5 mm, one side of which is cut to a radius of 300 – 400 mm (Fig. 1). The plates, in turn, is glued to the drywall.