Drywall screws showing through paint

[KevDawg]

Good afternoon everyone,

I'm curious if anyone has had this issue before.
I have drywall screws showing through the paint.
They look black. I haven't cut open the wall yet, but the two side exterior walls both have this happening.
The walls do need a good cleaning...

Is it thermal bridging?

I thought I'd see if anyone has had this issue before I cut a hole in the drywall.

I'm also reconsidering painting again to get rid of this issue.

I appreciate any input you may have.

 

[CTyankee]

Possibly rusting and bleeding thru?

 

[TheClaw]

That's "ghosting" from air, dust and moisture moving around in the wall. Prime and paint will take care of it.

 

[Toolfool]

Was the drywall properly primered before painting ?

 

[KevDawg]

Yes it was primed properly. Actually two coats, for some reason I thought it was a good idea at the time.

I appreciate everyone's advice.

I guess I don't need to cut a hole in the wall?

 

[BillK]

It is dirt. The drywall is slightly lower at the screws and it collects dirt. The screws on the outside of the restroom at my business are like that. Take some soap and water and wash it and you will see.

 

[wssix99]

They aren't along exterior concrete walls, are they?

 

[pb57]

Yep I have the same thing on my garage walls. It is just dirt that for some reason attracts to the screws. Paul

 

[The Cobbler]

same thing happens in a fire, the smoke highlights the screws, almost like the screws photograph thru the paint

 

[walta]

I think the problem is moisture in the air is condensing on the cold surface of the wall. There is less insulation where the stud is and the screw conducts heat better than the wood so the screw head is even colder and wetter.

You will need to keep the garage warmer and or dryer.

Walta

 

[The Cobbler]

^^^ yes with a thermal imaging camera you can see the screws in the drywall

 

[BillK]

You will need to keep the garage warmer and or dryer.

Walta

That does not help. My shop is kept at 68 degrees 24-7 and I still get the dirt at the screw heads.

 

[Daniel57]

possibly due to rusting

 

[Sweetcorn]

You can clearly see the studs as well.

Wood or metal studs?

 

[Jackfre]

"Ghosting" is the term. Home Energy magazine did an article on it years ago. I saw it with my DV wall furnaces back in the early 90's. No one knew exactly what it was but of course the new appliance was blamed. Now, they were sealed combustion so the ignition process had no affect on it. What was happening is that airborne dust and/or soot (freakin' candles) would circulate through the appliance pick up a charge and find a place to land, drywall screws, etc. Slide a picture aside and you would see the original color of the room.
My wife loves candles and as far as decorating goes in the house I have no say and could care less, but there are no candles burning in my house, unless the power is out. In 46 years it is one of my few wins in the house.

 

[KevDawg]

Wood Studs.

I was concerned with moisture or perhaps mold in the walls.
The exterior is stucco.
I know it would be smart to cut a piece of drywall out and have a look.
But don't love the idea of having to repair the drywall.

This is why I looked to you all before doing so.

I think i'll wash the walls and go from there. perhaps a repaint is in order as well.

 

[walta]

That does not help. My shop is kept at 68 degrees 24-7 and I still get the dirt at the screw heads.

68° should be warm enough. What is the indoor humidity?

While humidity is interesting the real question is about the dew point in the room.

You may want to monitor the garage on the coldest nights with something like this.

https://www.frys.com/product/6885096?source=google

Walt

 

[danielbuck]

I've seen that in a house that had a wood fire stove, the chimney wasn't quite sealed and would let a very tiny bit of smoke out, over time you could eventually see the wood wall studs and drywall screws.

 

[CTyankee]

I've seen that in a house that had a wood fire stove, the chimney wasn't quite sealed and would let a very tiny bit of smoke out, over time you could eventually see the wood wall studs and drywall screws.

Not doubting what you say about smoke/soot causing the darkening. But I've got to wonder if moisture levels aren't what causes this to happen. If studs/screws had a higher moisture level, it would seem those areas would be the ones to collect the airborne particles. If you took a piece of drywall with one part that was "damp" and and blew dust over it, the dust would likely stick to the damp spot and not the dry portion. Maybe the slight difference in moisture/temp isn't a big deal, but IMO it's definitely playing a part in causing the issue. If not due to any actual water intrusion, as the OP mentioned, thermal bridging is a reasonable explanation.

 

[Jackfre]

There are positively charged particles that attach to the screws. It isn't moisture. That may be an issue in the building, but is not the cause of this condition.

 

[couch67]

I think the problem is moisture in the air is condensing on the cold surface of the wall. There is less insulation where the stud is and the screw conducts heat better than the wood so the screw head is even colder and wetter.

You will need to keep the garage warmer and or dryer.

Walta

This. Having grown up in northern ontario I have seen this many times.

Did you say whether this was occurring in your garage or in your home?

If you have forced air heat, keeping the blower fan on all the time during winter can help with circulating air and reducing condensation on cold walls and windows. Another (more expensive) option is a heat recovery air exchanger, that would help with circulation and also reduce moisture levels. Insulation that reduces thermal bridging (ie skin the house with rigid foam) would also help but is obviously a more intensive solution (especially with Stucco )

As others have said washing the wall should remove it. You might get a few years before you have to do it again.

 

[CTyankee]

There are positively charged particles that attach to the screws. It isn't moisture. That may be an issue in the building, but is not the cause of this condition.

How do you explain the ghosting on the studs too?