Ghosting / Faded Vinyl Siding

[Mark P]

I’ve seen ghosting on drywall walls & ceiling and understand the principle behind why it occurs.

I have never seen ghosting on exterior vinyl siding. This is the west facing wall. You can see marks where the vertical wall studs are and the horizontal floor area between the 1st / 2nd floors and the 2nd floor / attic. The house was a display home built in 2004/5, and has sat empty for several years, since the builder went tits up.

It really looks more faded then stained. It was not unusually dirty when I wiped my wet finger across it.

So what causes vinyl siding to fade like this?

My only theory (really a shot in the dark) is as the sun heats up the west wall, the framing members retain the heat longer and get hotter and somehow causes the vinyl to faded unevenly.

Any ideas?

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[Scottpat]

Same principle as drywall ghosting. The studs bays are insulated and the studs are not, the studs are transmitting heat/cool to the exterior surface which then attracts particulates in the air.

[Bill Kibbel]

Persistent condensation.

[Mark P]

Same principle as drywall ghosting. The studs bays are insulated and the studs are not, the studs are transmitting heat/cool to the exterior surface which then attracts particulates in the air.

But would that not cause the studded areas to be darker?

[Mike Lamb]

Same principle as drywall ghosting. The studs bays are insulated and the studs are not, the studs are transmitting heat/cool to the exterior surface which then attracts particulates in the air.

I have seen this before. My guess was the walls were not insulated but I never knew if this was true. Cuiously, the ghosting I saw was also on the west side.

[Tom Raymond]

This would be a really good place to use an IR camera.

Tom

[Jim Katen]

Same principle as drywall ghosting. The studs bays are insulated and the studs are not, the studs are transmitting heat/cool to the exterior surface which then attracts particulates in the air.

But would that not cause the studded areas to be darker?

No. The studs carry heat from the interior to the vinyl. Those areas stay warmer, the areas around them are cooler and water condenses there. I see this a lot in the morning hours; condensation dripping off the siding between the studs.

People occasionally comment on it. One woman hired me to diagnose this very problem. She'd just had the siding installed and was sure that it was "leaking." (She was ramping up to sue the contractor.)

- Jim Katen, Oregon

[Rocon]

This would be a really good place to use an IR camera.

Tom

Really the only good an IR camera would do is give you the actual temperatures (usefull for verifying Scotts theory).

I believe as Scott sugests it is related to thermaly induced condensation. The low tech test would be to pressure wash the surface and see if it goes away. If it does not go away it would probably be a manufacturer problem with the siding. The siding might need some kind of thermal break.

The thermal photos would look very simillar to what the picture allready shows us.

[hausdok]

I'd say that Jim has it right and you're looking at a house where the installer didn't use any fanfold foam behind the siding.

OT - OF!!!

M.

[Mark P]

Another education - courtesy of TIJ – thanks all.

I don’t think anyone was terrible concerned with it, but I always try and provide as many answers as I can.

This was a show home and the buyers are getting it, from the bank, for almost 100K less then the original asking price.

[Garet]

I say, never pressure wash a house. It drives moisture into places where it wasn't designed to go.

[Mike Lamb]

I don't believe anyone around here puts foam behind vinyl siding on newer construction. Just Tyvek over OSB. I still find this ghosting atypical. I've only seen it once.

Wall insulation is important in my climate. Would you say that lack of or crummy insulation in the wall is not likely to cause this issue (condensation and ghosting) and is not worth investigating?

[Mike Lamb]

I don't believe anyone around here puts foam behind vinyl siding on newer construction. Just Tyvek over OSB. I still find this ghosting atypical. I've only seen it once.

Wall insulation is important in my climate. Would you say that lack of or crummy insulation in the wall is not likely to cause this issue (condensation and ghosting) and is not worth investigating?

I'll assume lack of insulation in the wall cavity does not contribute to this phenomenon. Thanks.