Help! What`s Causing Gray Striping on Exterior Walls?

[SteveR]

Hi all,
Does anyone have any idea why the walls of a unit would have this gray striping where the studs are? It`s a corner unit, and the discoloration appears on both sides of building--on all the exterior walls, but not the interior walls. The building has a concrete exterior with metal studs. According to the on-site manager, this hasn`t occurred in the unit directly below.

I`d appreciate any information on what might be causing this.

http://www.srsrsr.smugmug.com/Architecture...785046681_7DoHr

Thank you!
Steve

 

[ToddStokowski]

I believe the striping is caused by the cold migrating from the outside to the inside. If you check the width of the exterior walls, my guess is that they are only as 3-4 inches thick, meaning that the framing was done with 2*4s not 2*6s resulting in poor insulation and the metal studs act as a conduit for the cold. When the unit is painted in the winter, the striping will occur. If you paint in the summer, you won`t see the effects until the next winter.
Those are my thoughts.
Todd

 

[housedoc]

My guess would be inadequate (or missing) vapour barrier. Punch a hole and have a look, if you feel so inclined.
Try using a high quality primer and paint. Something other than white?

 

[SteveR]

QUOTE (housedoc @ Feb 10 2010, 03:54 AM) My guess would be inadequate (or missing) vapour barrier. Punch a hole and have a look, if you feel so inclined.
Try using a high quality primer and paint. Something other than white?

Thanks for the response. So far no one has felt any dampness at the stripes, but if it is a VB issue, then maybe there is some corrosion from the metal studs bleeding through the drywall. Hmmm.

 

[SteveR]

QUOTE (ToddStokowski @ Feb 9 2010, 08:33 PM) I believe the striping is caused by the cold migrating from the outside to the inside. If you check the width of the exterior walls, my guess is that they are only as 3-4 inches thick, meaning that the framing was done with 2*4s not 2*6s resulting in poor insulation and the metal studs act as a conduit for the cold. When the unit is painted in the winter, the striping will occur. If you paint in the summer, you won`t see the effects until the next winter.
Those are my thoughts.
Todd

Thanks for the reply Todd,
Given that there are metal studs, cold could definitely be an issue. I`ve just never heard of cold discoloring interior paint, esp. when the unit was occupied. Hmmm.

 

[asifghayoor]

Steve,

I have seen this many times, its very simple, the studs are cold conduits relative to the insulation or air in the walls. This creates a situiation on the walls where you have colder slower air in front of where the studs are. Any soot or dust in the room tends to stick to that portion of the wall. You see this often in churches where they burn candles or in smokers houses. Its very difficult to clean as the particles are microscopic and stick really well to the walls. sorry i dont have a solution but i know clearly what the problem is.

Thanks

Asif Ghayoor P.Eng



QUOTE (SteveR @ Feb 9 2010, 08:31 PM) Hi all,
Does anyone have any idea why the walls of a unit would have this gray striping where the studs are? It`s a corner unit, and the discoloration appears on both sides of building--on all the exterior walls, but not the interior walls. The building has a concrete exterior with metal studs. According to the on-site manager, this hasn`t occurred in the unit directly below.

I`d appreciate any information on what might be causing this.

http://www.srsrsr.smugmug.com/Architecture...785046681_7DoHr

Thank you!
Steve

 

[SteveR]

QUOTE (asifghayoor @ Feb 10 2010, 02:28 PM) Steve,

I have seen this many times, its very simple, the studs are cold conduits relative to the insulation or air in the walls. This creates a situiation on the walls where you have colder slower air in front of where the studs are. Any soot or dust in the room tends to stick to that portion of the wall. You see this often in churches where they burn candles or in smokers houses. Its very difficult to clean as the particles are microscopic and stick really well to the walls. sorry i dont have a solution but i know clearly what the problem is.

Thanks

Asif Ghayoor P.Eng

Thanks Asif,

That sounds like pretty good confirmation that of the issue. The info we just found at www.Bozzle.com calls it `Pattern Staining`. We`re now wondering if the tenant burnt candles frequently. The PM said the area has had a colder than typical winter. I was hoping it would wash off easily, but it sounds like a paint job is in order.

I appreciate the response, Best Wishes,
Steve

 

[cldemott]

Yes this also is seen with moisture issues in the winter months around floor heat registers and carpet. The blackened carpet around the registers happens when ducting isnt a tight fit to the cut-out in the floor. Pink Solution works well for the blackened carpet. I would definitely try that on the walls first. Great product for tough stains of any kind.
Linda