*The above Indian Sandstone project used HMK R60 Moss & Mildew Remover, followed with HMK R55 Intensive Cleaner.
To remove dirt and grime from Exterior Stone, we suggest using the following process:
(For heavy moss and Mildew, we suggest spraying first with R60)
1. Mix a solution of 1-part R55 Intensive Cleaner to 6-parts clean water in a bucket.
2. Using a stiff natural bristle scrub brush, dip brush in cleaning solution and apply to dirty stone and scrub area for 1 minute.
3. Allow to dwell on surface for 10 minutes to activate cleaning action (do not allow to dry), apply more cleaning solution of needed.
4. Scrub area again aggressively for 3-5 minutes.
5. Thoroughly rinse area with clean water.
6. Allow area to dry.
If deeply penetrated stains remain, repeat process but allow solution to dwell for 15 minutes.Rinse very well with clean water. Allow to dry.
To Protect Natural Stone from dirt, grease, and other contaminants, use a professional quality stone Impregnator.
Cleaning Exterior Stone with HMK Stone Care Products
HMK makes a full line of Professional Grade products specifically designed for Natural Stone
Moss & Mildew R60 Moss & Mildew Remover
Efflorescence R65 Terra Cotta Cleaner - but don't let the name fool you! Cleans all stone surfaces - Acid Base
Leaf Decay R60 Moss & Mildew Remover
Tire Marks R55 Intensive Cleaner
Grease R55 Intensive Cleaner
Metal Residue R63 Concrete Film Remover - Removes Anodized Aluminum residue from roof flashings and drainage
Grout Residue R55 Intensive Cleaner for Mild Residue. For Heavy Cement or Grout Residue use R63