Mask for spraying SH?

Does anyone have a suggestion for a mask to use when spraying house wash and roofs?

John Somers
Aqua Clean Pro Pressure Washing
704-740-2163

All day everyday.

3M Particulate Respirator 8576, P95, with Nuisance Level Acid Gas Relief (Pack of 10): Amazon.com: Industrial & Scientific

There are better masks than may be beneficial when on a roof but the one listed gets worn all the time because it is just so comfortable.

When do you replace the mask or can you use them over ?