Medicare allows for mask cushion replacement every three (3) months, and a complete mask system replacement every six (6) months. CPAP manufacturers and vendors suggest these replacement schedules as well. In our experience, most mask cushions begin to deteriorate after about six months of use.
Hereâs what you do: 1  Figure out the length that you want your finished sleeve to be. On the outside of the shirt, mark that spot with a line. 2  Using a see-through ruler or regular ruler, mark a line 1 Â½â underneath the first line. Use the ruler to continue that line across the sleeve. 3  Repeat on the other sleeve.  Cut on the second line you drew.
Nail the sleeve to the formwork either central in the slab or for slab depths over 12â³ so the top of the grout box is level with the top of the slab. Do not remove the label over the nailing plate as this prevents ingress of concrete into the sleeve. Fix the local reinforcement. Pour the concrete, and when of sufficient strength, strike the formwork.