Housing and Community Development

This message has been cross posted to the following Discussion Forums: Housing Knowledge Community and Custom Residential Architects Network .
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Does anyone have some resources for maintaing brass, stanless steel or polished granite outside. What finishes last. I have a project where the finish is going on all three products. The Items are being sprayed by the well water irrigation. Exposure to sun as well. We have a chalk like substance developing and staining issues. I suspect minerals in the water, The granite is loosing its gloss. Any ideas? ------------------------------------------- Donald Duffy AIA Don Duffy Architecture Charlotte NC -------------------------------------------

I think you are on the right track suspecting the irrigation water as your problem source.  In our area shallow wells sometimes used for lawn irrigation contain many minerals, usually the worst of which is iron that produces a reddish stain when allowed to wet building components.  I suggest you adjust your lawn irrigation sprinkler head layout and/or their spray pattern to avoid normally wetting built components.  Depending on the current head layout you may have to add heads to accomplish this.  If you are getting pitting on the stainless steel, what Type (i.e. 302, 304, or 316) of stainless steel was installed?  Type 316 has to most chemical resistance, but you likely didn't have it provided unless you specified it. 

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Craig Hess AIA
Elness Swenson Graham Architects, Inc.
Minneapolis MN
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I think you have to get the irrigation system adjusted so the well water does not spray on the finishes.  I do not believe there is a coating system that will keep the mineralization from forming over time.  It will just collect on the coating.  You might try some of the anti-graffiti products.  There is a chance they will change the look of the materials themselves.  Even so, regular cleaning will be necessary.  You could also look into products by Prosoco, http://www.prosoco.com/.
I grew up in south Florida where many homes had wells for watering the yards.  All had rust stains on their houses from it.  When I lived in Chicago, there were numerous metal refinishing companies doing a very good business each year from cleaning the storefronts and other surfaces of buildings from oxidation and winter weather staining.
In your case, fixing the source of the staining seems to be the first thing to correct.


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Roger Retzlaff AIA
Green Bay WI
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