I wrote an article that was just published in E Clean Magazine. There is currently no information available on the subject and many have not seen the problem in their area. I am attaching photos since very few are included in the magazine but they really help to tell the story.
“Stud striping” or “structure striping” is a visible pattern that can be seen on building exteriors, typically on the north side and other shaded areas. This phenomena is a common site on building exteriors, particularly in areas where there is consistent moisture due to humidity, coastal marine layers, low lying valley fog, etc.
The dark shading is due to the proliferation of the cyano bacteria, gloeocapsa magma (GM). The pattern affect is the result of the direct contact transfer of heat from structural members such as studs, plates, headers, etc. The bacteria requires moisture to grow and flourish. The transfer of heat from framing dries the exterior surface quicker than areas where there are open or insulated bays. The result over time is a pattern, clearly showing the location of structural members below the exterior surface.
Structural striping is not limited to walls. It can also be evident on composition roofs, with rafters being the heat transferring members. While GM has infested all roof types, a pattern due to the bacteria can typically be found at unheated areas such as eaves and overhangs. This perimeter roof shading is particularly obvious when the attic space has not been well insulated and allows heat from the home into the attic area.
In general, wood and tile roofs do not show a patterned growth of GM. This is because wood shingle and shake roofs have moderate insulating properties. Properly installed tile roofs create a natural thermal break and generally do not come into direct contact with heat transferring structural members.
Darker colors tend to hide the bacteria while lighter colors make the shading more obvious. As the bacteria develops and darkens with time, structural framing, heated and non-heated areas and even areas with irregular insulation become clearly visible. Solid building materials such as brick and mortar are equally affected by GM but there is no pattern due to internal heat transfer.
Commercial surfaces accentuate structural striping
Smaller residential homes with many windows, doors and comparatively smaller surface areas tend to obscure the pattern effect. On the other hand, commercial buildings with large monotone surfaces accentuate the effects of structural striping. Typically, commercial building walls show the consistent stud pattern that results from both metal and wood studs.
The best way to remove stud striping
The safest and most effective method to remove the bacteria that causes stud striping is using a chemical “soft wash” cleaning. This is true for at least two reasons. The first reason is that soft wash cleaning eradicates the bacteria that is the source of the problem. While using high pressure may remove the visible bacteria from the surface, it does not kill it. The great results from the soft wash method last much longer than cleaning with pressure. Another reason for using the soft wash method is that it causes no damage. Many of the exterior surfaces where stud striping is evident can be damaged from the use of high pressure. Chemical cleaning uses no more pressure than a garden hose; yet the results are fast, thorough and effective.
I came up with the information myself, I also am friends with a university biology professor (a braniac that knows way too much) so I made sure what I concluded agreed with what he knows. I don't think the issue is very widespread but I believe it will be. It is becoming more common in my area now but has only been developing over the last few years, I have literally watched it happen. As a building and cleaning contractor it really stood out to me so I had been analising how it grew, looking for any thing written on the subject and working on an explanation of it that made sense.
Homeowners are pretty much in the dark regarding the bacteria that we understand and remove every day. But, I believe believe the pattered aspect (stud striping) will become increasingly obvious and easily visible to any one. Seems to me they will most probably start searching for information on the subject. Since there was none I could find I thought it was a good opportunity to write something about the subject.
I came up with the information myself, I also am friends with a university biology professor (a braniac that knows way too much) so I made sure what I concluded agreed with what he knows. I don't think the issue is very widespread but I believe it will be. It is becoming more common in my area now but has only been developing over the last few years, I have literally watched it happen. As a building and cleaning contractor it really stood out to me so I had been analising how it grew, looking for any thing written on the subject and working on an explanation of it that made sense.
Homeowners are pretty much in the dark regarding the bacteria that we understand and remove every day. But, I believe believe the pattered aspect (stud striping) will become increasingly obvious and easily visible to any one. Seems to me they will most probably start searching for information on the subject. Since there was none I could find I thought it was a good opportunity to write something about the subject.
Awesome Article Eric, well researched, and very well written!