Indoor Stain Removal & Prevention FAQs

Q&A on Stains on Indoor Surfaces, cause, cure, prevention

What is the best top coat sealant or paint to use over stains

Can I paint a lacquer primer or apply a coating of spray shellac over Zinsser 1-2-3? I recently moved into a friend's apartment and it badly needs painting. My friends are serious candle burners, and there are dark outlines around all the places where pictures and artwork hung, throughout the apartment.

Started with the bedroom - swept and wiped down the walls after using compound to repair the various places in the room where the paint was falling off the wall ....then applied primer ....

painted the ceiling Sat and the walls Sunday. When we went to remove the tape about an hour after painting, both the ceiling paint and the wall paint lifted/fell off in a sheetlike way.

I was thinking that perhaps years of oily candle residue made the walls 'slippery,' and it would explain why the primer didn't even stick to the ceiling.

OR maybe we didn't remove dust from sanding compounded areas, tho in a patch test afterward of the wall cleaned with tack cloth, primer still didn't stick. The Zinsser primer said don't use TSP, so we didn't wash walls beforehand.

Investigating, I found your website. There are ghost marks all over the apartment -- could that be why primer isn't sticking? Also, I've already primed hallway, which has black ghost marks all over it. Can I apply lacquer primer sealer over the primer (or spray shellac), or do I have to do something to remove it (if so, what? sanding?).

Thanks for your help!! At least we didn't paint the entire apartment before finding out about this! Warm regards, Marian Heller

Reply:

I looked at the photos you sent by email - it looks as if there was a water or moisture or other problem; indeed this is a severe paint adhesion loss problem.

Before repairing or repainting I would make sure there were no leaks into ceilings or walls since if there were you have other investigation to do before painting.

After being sure there is no in-cavity damage or that there are nor were leaks there, you can clean with a TSP substitute, let dry thoroughly, then you can

paint with a lacquer primer-sealer (such as Bin or Enamelac) and then a finish coat that gives the color and type of finish (flat, semi-gloss or gloss) and you should be OK.

If there were leaks - ever - into building cavities, especially where mold-friendly materials such as wood, drywall, paper, gypsum board, paint, some insulation products, were used, then some investigation of those cavities for hidden mold or damage would be in order.

Marian said: OK to use laquer primer sealer atop existing sealer or paint?
Thanks

The super is coming by for a moisture reading tomorrow, so I'm investigating leaks.

Can I clean and apply the lacquer primer-sealer right over the one wall (different room than the disaster site) that has Z 1-2-3 primer, as well as walls I've not yet primed? thanks!

Reply:yes

I've had good success using a lacquer type primer sealer over surfaces that had persistent grease bleed-through staining.

As long as you 've done basic surface cleaning it's usually OK. Rarely we find a wall stain that itself is dissolved-by and leaks through the lacquer.

Watch out: Beware of water-based stain killers that work fine on many surfaces but don't seal as universally as lacquer-based products.

What causes brown stains on indoor walls and ceilings?

Can anyone tell me what is going on with this wall - see the brown stained walls in the photo above - On 2018-05-07 by Briana35 -

Reply by (mod) - how to diagnose & cure brown stains on indoor walls & ceilings

Briana, the dark vertical lines probably mark the location of wall studs - making these stains look like a variation on the thermal tracking we discuss

at THERMAL TRACKING BRIDGING GHOSTING

Usually those stains show up as dark gray, almost black areas.

But IF the airborne dust that is being deposited contains brown material, brownish or tan stains can appear in the same pattern.
Examples of brownish stain particle sources include

• results of interior re-finishing,
• sanding a wood floor, and
• nicotine stains from smokers.
• red yeast growth - a fungal growth we sometimes find in buildings if the indoor area has been wet or flooded
  

What causes black oily dots in our bedroom on walls and ceilings?

There is black oily dots above master bedroom and bath close to ceiling. Ive cleaned with bleach. Residue is oily . what is thisOn 2018-03-14 by Anon

Reply by (mod) - diagnosing black oily dots or stains indoors

From just your photo I can't tell what that black residue is. I might be looking for sources of black dust or soot.

For example if your building is heated by an oil or gas-fired heating Appliance it might be operating incorrectly or even un safely.

Or we could be seeing a mold growth on the indoor wall surfaces, particulaly if your home is damp or has been wet or flooded.

We'd need a closer look, a lab sample, or perhaps best for you, an onsite inspection by a home inspector - see the EXPERTS DIRECTORY found at our page top links.

Who can diagnose and repair thermal tracking problems?

Who can diagnose and repair thermal tracking problems? On 2017-12-01 by T. Law

Reply by (mod)

T Law

You'll need to discuss the concern with whomever you find to be sure they have expertise specific to thermal tracking

Among environmental inspectors and home inspectors you can find at the page top EXPERTS DIRECTORY LIST or from a search for "indoor environment test expert" in your local area.

Insurance Company says Ignore Black Stains that Appeared on our Ceiling after a Tree fell on our House

We had a large tree fall on our house in a windy snow storm.

The tree was about 65 feet tall and weighed aprox. 2,500. Lbs. the biggest part landed on our vaulted ceiling.

That night we noticed a black oval spot on ceiling..the next day more blackish spots with longer looking lines.

it looks just like your ghosting pictures. The tree was removed they can not see punctures holes on the roof but there is damage on the roof,

They did not tarp or repair the area until 2 weeks after the tree fell. Instead of tapping in the one area they patched with shingles on top of shingles.

It has now rained 3 days..

New places appeared or the marks are bigger or longer.

One of these stripes goes from the ceiling to the baseboard. One area is horizontal and is 8 feet by 9 inches..

We have not seen any water dripping in. It looks like what you describe as ghosting., we have lived in our home 16 years and never had this happen until the tree fell..any ideas on why this happened? We need help. On 2016-03-14 by Bev. Eaves

by (mod) - sounds like house not properly protected from rain (water) damage after roof was damaged

Bev:

Good grief. I don't quite know what to make of this. If water wet drywall or insulation and those wet materials were left in place, mold contamination is likely to form - that's true even if water didn't drip into the occupied space.

Ghosting lines generally form over months or years, not just a few days

Other lines or stains may appear when contaminants dissolved by water leach through building materials.

by Bev: insurance company says to ignore black ceiling stains as "common"

Thanks for your knowledge and quick response.. The Inscurance company does not want to fix it saying these marks are common with vaulted ceilings.

There were no marks on our ceiling or walls prior to the tree. What would you do if this was your home? I have 2 kids with health issues ( breathing). Should I call a home inspector?

by (mod) - look for water damaged insulation, drywall, mold

Fixing the marks is not the concern, Bev. That's simple cleaning and painting - not an insurance topic unless you had afire or puffback explosion or some similar event.

Watch out: Saying that "marks are common on vaulted ceilings" without an investigation as to the cause is a dangerous ducking and weaving exercise by your inurance company that could end up costing them far more if an active leak and mold contamination are missed - allowing that problem to grow still larger and more costhy to repair.

The concern is whether or not there have been leaks that need further investigation; you can interview home inspectors to find one who has familiarity with and is willing to perform a more competent inspection of this particular question - some of those folks prefer the easier faster task of visual-only inspections but here I suspect that a few small test-cuts to explore the most-suspect areas are what's needed.

• Remove any insulation that has been wet
• Remove any drywall that has been wet
• Remove all drywall that is moldy and extend removal at least 1 rafter bay or ceiling joist bay beyond any visible mold
• Clean the exposed surfaces after they're dry
• Then the building can be restored

by Bev

Thank you for the help. I will move forward and contact a home inspector. Your response is appreciated very much.