JD Metals Clean Metal Roof

Metal roofing may be durable, but winter weather has probably coated it with a layer of dust and grime that detracts from its appearance.  Like everything else, proper cleaning will enhance the look and life of your roof. Our Weather XL roofing panels here at JD Metals are coated by Sherwin-Williams®, a leader in the industry.  Here are some of their cleaning recommendations to get you started.


NOTE: These suggestions are for PAINTED metal, not unpainted Galvalume. 

The first thing to remember when cleaning your roof is to take the proper precautions: By definition, roofs tend to be rather high off the ground and not very flat. Always use care and be aware of your surroundings when working on ladders or walking on a roof.  Also, never use wire brushes or abrasive cleaners on your metal roof: these are likely to scratch the surface and should be avoided.  Instead, use a soft cloth or brush, as well as the recommended chemical solutions for the job at hand.  Make sure to always test any detergents or chemicals in an inconspicuous place to ensure that it does not mar the appearance of your roof.  A few preparations before you begin may save you time and money later!


Using the proper detergents or chemicals for your specific problem is very important for getting the best results.  In other words, knowing what’s up there will help you get it off in the fastest and easiest manner.  With all chemicals, make sure to use care when handling: gloves and respirators may be necessary in certain cases. Know what chemicals you are dealing with and how to handle them safely. Below are listed some of the common dirt dilemmas that you may encounter, as well as appropriate removal strategies.


For run-of-the-mill dirt and grime, a 5% solution of a standard detergent in water is all that is necessary.  Apply the solution with a soft cloth or brush, and make sure to rinse thoroughly with water. 


The sticky-gooey stuff can make a roof look less than its best.  The trick here?  Isopropyl (rubbing) alcohol.  Apply to the stain and rub gently with a soft cloth.  As always, it is best to start in an unobtrusive spot, just to make sure, and rinse afterwards. 


Just the word “mildew” sounds icky- it has “ew” built right in.  This slimy spreader likes the shade, and places with high humidity permit it to grow unhampered.  The solution is, well, a solution: 1/3 cup powdered laundry detergent + 1 quart bleach (sodium hypochlorite 5% solution) + 3 quarts of water.  Test in an inconspicuous spot and use soft cloths or brushes to apply.  Make sure to systematically rinse off all of the solution.


Now we are escalating to acids: hydrochloric, citric, muriatic, or oxalic. Use care when handling: it is ACID. Mix 1 part acid to 10 parts water and limit exposure to less than five minutes.  Apply with a soft cloth or brush, and rinse this one off with lots of water (again: ACID).  It is also very important to try the mixture in an obscure spot to ensure there is no fading. 


Water is always the key to a good cleaning job.  It needs to be mixed with the detergents and chemicals in the proper ratio: too little water and the detergents can be too strong, too much water and the cleaning effect is diluted.  A thorough rinse job is also extremely important for optimal results, with leftover detergents creating a dull appearance. High-powered sprayers, however, are too powerful for your metal roof and can severely damage the finish.  Very light pressure washing is best in this situation.

Like all parts of your home, your roof needs routine care and maintenance.  With the proper tools, the appropriate solution for the dirt at hand and a little care, your roof can look as good as the day it was installed.  To see the Sherwin-Williams Care Guide, click here.