TSP=TRISODIUM PHOSPHATE
Availalble at any hardware or paint store.
Uses for TSP...
TSP is used for washing surfaces prior to painting, especially exterior surfaces. Liquid bleach is often added to TSP if there is mildew on the surfaces. The TSP and bleach act in concert to both kill the mildew and remove its characteristic stains. It may be used on inside surfaces also, but try to mask all surfaces except the one you want to clean. It can damage many metal and painted surfaces, and can stain woods. It is not recommended for use on glass, either, since it will leave a filmy residue.
TSP and TSP-bleach solutions may be applied with a sponge or brush, or can be sprayed on. Generally, you will have to apply some elbow-grease if the mildew or other staining is severe. If you are washing the exterior of a house, it may be worthwhile for you to look into the rental of commercial powerwashing equipment. You may be able to do all necessary cleaning from the ground level, sparing you the risk of extra ladderwork.
Mixing TSP...
TSP is a very strong cleaner at the dilutions normally used, which vary from 1/2 cup TSP to 2 gal. warm water for "heavy duty cleaning" to 1 cup TSP to 3 quarts warm water for "ridiculously heavy duty cleaning" (source The Savogran Company). For mildew killing, household bleach is added to the TSP/water mixture. The recommended ratio is 1 part household bleach to 4 parts water.
Read the manufacturer's mixing ratios, as they may vary.
PRECAUTIONS AND WARNINGS...
TSP is a strong base and can cause severe eye damage and can burn unprotected skin.
Wear suitable clothing and eye protection. Keep away from skin and out of gloves.
