FAQs about the causes of stains on ceilings and walls:

This article series describes how to identify and diagnose ceiling stains in buildings focusing on the cause of various interior wall and ceiling stains and explains how to recognize thermal tracking, thermal bridging stains, building air leaks, and building insulation defects.

Ceiling and wall stain questions & answers

These questions & answers about the cause, cure, prevention, painting-over ceiling stains were posted originally

at CEILING STAIN DIAGNOSIS - you'll want to check out the diagnostic and repair advice given there.

Photo: black stains on a cathedral ceiling - discussed below for Dee.

[Click to enlarge any image]

On 2022-12-31 by InspectApedia Publisher - water leak mixed with rodent feces may be cause of stain

@Anonymous,

Sounds like excellent detective work to me and perfectly reasonable conclusions.

A bit more detailed inspection to find the water source is in order.

We don't know at this point if it's a roof leak or an accumulation of frost in the attic from inadequate attic venting and air leaks into that space.

On 2022-12-31 by Anonymous

@InspectApedia Publisher, thank you for the reply. The stain is about 6 inches long. I went up to the attic to check everything out and I found two things:

1 - Old, dry raccoon feces that were clearly not cleaned up when we hired professionals over the summer to address the raccoons in our attic

2 - Moisture on the wood and water damage on the paper insulation bottom near the old feces

My guess is that we had a water intrusion, possibly related to ice melting, and the water mixed with the feces to give us the stain. Does that seem plausible? Our first call was obviously the pest control company. Should our second be a handyman? Roofing company?

On 2022-12-29 by InspectApedia Publisher

@Anonymous,

Thank you for a nice challenge: that's not a stain that I can diagnose - some note on scale (size) would be helpful.

My suggestion: in the attic, inspect for evidence of frost, ice, or leaks or leak stains, and then pull up the insulation over this spot to look at the attic side of the ceiling drywall.

Let me know what you see.

On 2022-12-29 by Anonymous

This stain appeared overnight on our ceiling on the first warm day after several days of extreme cold. The house is fairly new (2009) and the roof is in excellent shape. There is a ridge cap above the attic, but it appears to be in good shape.

On 2022-11-07 by InspectApedia (Editor) - cluster of brown spots on the kitchen ceiling

@Elissa,

Those are leak spots, usually from a leak from above. I think I see both the round leak stains and possibly a bit of mold growth.

Keep in mind that an intermittent or prior leak can wet the cavity side of drywall but measure dry weeks or months later; still it an inoculate a mold colony in the cavity that might ultimately also show up on the exposed wall or ceiling surface.

For such a small issue as in your photo I might violate my mold cleanup guideline for drywall and just try a household cleaner on the surface, then watch for a recurrence.

But if you suspect that there could have been a leak into the cavity above or if the stains and mold recur, then remove the drywall, clean the exposed surfaces, find and fix the moisture source.

On 2022-11-07 by Elissa

We just noticed this cluster of brown spots on the kitchen ceiling. A little less than a year ago we opened a wall about a foot away from this part of the ceiling so the spots are on both old painted ceiling and new ceiling drywall (joint compound) unpainted ceiling.

My husband checked the moisture reading in the ceiling with a pin moisture meter and where the spots are is 0.6%. We cranked up the heat to see if the radiator pipes are leaking but again, no change to the moisture level. Any idea what these could be besides water?

On 2022-12-06 by InspectApedia (Editor)

@Anonymous,

Stains just around nails are often thermal tracking - dust deposits on the cooler area caused by the nails or screws

See details at

THERMAL TRACKING BRIDGING GHOSTING - home

On 2022-12-06 by Anonymous

@InspectApedia (Editor),
Could this be from the steam from the shower? It is only around the nails on the ceiling

On 2022-12-06 by InspectApedia (Editor)

@Anonymous,

If you're referring to the September 28 posts by Yan, we have not heard follow-up from that reader, but the stains certainly looked like evidence of leaks from above. The tasks are to find and fix the leak and then remove any drywall or ceiling tiles that were wet or moldy.

On 2022-12-06 by Anonymous

@YIN
did you find what the problem is? I have the same exact issue

On 2022-09-29 by InspectApedia-911 (mod) - water leaking from above following a butt joint in ceiling drywall

@Yan,

The larger stains are in shadow in your photo and a bit hard to make out.

But the presence of those small brown ceiling stains in a line suggests that there may be water leaking from above following a butt joint in ceiling drywall.

That could be from a roof leak or a condensation problem or another water source.

It would make sense to inspect the roof space or attic space above that area or if it's not an addict but rather another occupied floor above then look for plumbing supply or drain piping nearby.

On 2022-09-28 by Yan

Noticed the stain from about a year ago. It's the bedroom ceiling on 1st floor. A handyman who came by said it's not water leak. Can you comment what it might be?

On 2022-07-09 by InspectApedia-911 (mod) - check attic insulation for clues

@Oscar,

Did you lift up the insulation to look at the attic side of the ceiling drywall above that stain? That would be diagnostic. I'd like to know if for example there's a drywall joint in that location, and of course whether or not there are stains or a water source nearby.

Also ask what else changed during that brief interval over which you say the stain appeared.

On 2022-07-09 by Oscar

These literally appeared over night. Not wet. No water in the attic. Roof is less than 20 years. 40 year old house in great shape.

 

On 2022-06-16 by InspectApedia-911 (mod)

@Avon,

I'm missing almost a hundred percent of the information one would get on site, but it looks to me as if that's a suspended ceiling with drop-in tiles.

One is showing what looks like leak stains along the edges.

It would be appropriate to lift the tile and look at its back surface and to look above that area to see if there is a leak source.

On 2022-06-16 by Avon

Any clues on what this is!

On 2022-05-13 by Inspectapedia Com Moderator - brown splash stains

@usman,

Looks like food or drink were splashed onto a wall or ceiling

On 2022-05-13 by usman

please help - what is this

On 2022-03-29 by Inspectapedia Com Moderator

@Mel,

Perhaps A/C condensate leakage?

On 2022-03-29 by Mel

Hi. Can anyone tell me what this stain is from? There's no color to it. I removed the vent and the duct looks sealed. No other plumbing or water source nearby. The area above would be second story subfloor. Thx.

On 2022-03-20 by Inspectapedia Com Moderator - ghosting stains require further investigation for source and action

@April,

It certainly seems possible that moisture or condensation on or in the cathedral ceiling combined with air movement across those cooler or damp surfaces will deposit any airborne particles. including soot from a fireplace or an improperly operating oil or gas burner or even simply house dust.

First priority is to check for unsafe conditions that create soot, such as an improperly operating oil or gas burner.

A second direction of Investigation is of course to investigate the ceiling and sealing cavity for trapped moisture, moisture damage, and even mold in the ceiling cavity.

On 2022-03-20 by April

@Inspectapedia Com Moderator, yes, they are the darkest above the ceiling fan. The confusing part is they appeared after I had been in the home for 2 years. I stopped using the fireplace after I thought it could be from the soot, but it didn’t seem to help.

The room in question is the warmest in the summer more than likely due to lack of insulation and age of home.

On 2022-03-06 by Inspectapedia Com Moderator

@April,

It's quite possible that those are ghosting stains - do you find that they are darkest above the ceiling fan? That may be diagnostic.

On 2022-03-05 by April

I live in a 70s built home. My great room has a vaulted ceiling with these stains. Mold or ghosting?

On 2022-01-09 by Inspectapedia Com Moderator - intermittent water leak or water entry

@Marcia,

You may have an intermittent water leak or water entry of some kind if the stain comes and goes. It's hard to tell since your photo is slightly blurry.

In the article above, see the section

DIAGNOSTIC GUIDE TO CEILING STAINS

where there's a list of common sources of stains.

You may need to access the space above that stain in order to check for a water leak or another possible source

Please let us know if you have additional questions.

On 2022-01-09 by Marcia

What causes this stain to appear at times and at other times it’s gone

On 2021-12-20 by Inspectapedia Com Moderator

@Shelley,

Check the attic side of that ceiling drywall for leaks.

On 2021-12-20 by Shelley

Hi, this brownish stain recently appeared on our bedroom ceiling. We sleep downstairs in the summer and upstairs in the winter. We were about to move upstairs when we noticed the stain.

There is no evidence of a leak, the insulation is dry. An electrician did not think it is to do with the fan since it doesn’t look like a burn pattern. The ceiling was last painted about 3 years ago. Thanks, I hope you can help. Merry Christmas!

On 2021-12-14 by Inspectapedia Com Moderator

@toni,

Try adding an image which will give us a better idea of size, color, etc.

Also see our explanation of THERMAL TRACKING BRIDGING GHOSTING

as that can explain dark spots around nails and screws in drywall

On 2021-12-14 by toni

On my kitchen nook ceiling, where the nails/screws would be for sheetrock, I see dark spots. The spots are not soft. the nook has nothing above it, it has it's own roof which was re-done about 4 years ago.

On 2021-08-11 by inspectapedia.com.moderator - need to inspect the attic to determine cause of water spots

@Yin,

To get beyond wild guessing to try to offer useful answer I have to say that what's needed is an inspection in the attic above the area of those leaks.

On 2021-08-10 by Yin

Hi, we are seeing some water spots forming a linear pattern on one of the bedroom's ceiling, is it possible to tell from the image whether it is a rain/roof leak or internal ac/pipe leak? Thanks in advance.

On 2021-07-25 by mak.church (mod)

@Anil,
I would start by looking for a leak in the roof above. It's not possible to know a cure until we know the cause. Feel free to ask more questions as you explore further and post additional photos of what you find.

On 2021-07-25 by Anil

Hi ,
I can see some dark markings on our alfresco. What could be the reason and how to cure this

On 2021-03-09 by (mod) - will additional insulation in the attic stop the ghosting marks?

@dick,

To stop thermal ghosting stains we need to

- fix drafts in the affected wall or ceiling or floor

- add insulation if those cavities are not adequately insulated - as you suggest

- find and fix sources of abnormal soot or other house dusts (some of those may indicate an unsafe heating system!)

- find and fix sources of abnormal interior moisture

On 2021-03-09 by dick

will additional insulation in the attic stop the ghosting or will more ventilation in the attic be needed?

On 2021-01-13 - by (mod)

Patrick

I'm so sorry that I can't say something more useful but the photo is quite blurry and all I can make out or what look like if you separated dark spots. You might first check to be sure there are no leaks above.

Perhaps we can take a closer look and have a sharper photo

On 2021-01-13 by Patrick

What are these black spots on my living room ceiling, no water pipes in ceiling. Its a cathedral ceiling so the only thing above it is the roof

On 2020-11-07 - by (mod) -

Yes Casey that's almost certainly thermal tracking on the ceiling - THERMAL TRACKING BRIDGING GHOSTING - home

inspectapedia.com/interiors/Thermal_Tracking.php

On 2020-11-07 by Casey

Hi,
Can you tell me if this looks like thermal tracking?
After reading through your page I’m now thinking this is what it is.

On 2020-10-25 - by (mod) -

Claire, that looks as if there may be leaks from above. What is over this area?

Roof leaks? Plumbing leaks? Spills? HVAC ducts dripping condensate?

On 2020-10-25 by Claire

I have recently started to get Grey patches appearing on my kitchen ceiling and am unsure of what they are and how to go about checking? I am unsure what sort of tradesman would be able to look at this and tell from looking. I have attached a picture:

On 2020-10-06 - by (mod) - black spots may indicate mold contamination on cellar ceiling

Margaret:

If you are saying that the cellar ceiling is covered in black spots I suspect that the gypsum board or drywall installed on the ceiling is mold-contaminated, possibly because of wet conditions there.

See example photos and details at DRYWALL MOLD TESTING

On 2020-10-06 by Margaret

12 months ago I had underfloor insulation fitted in my cellar. It was fitted and then plaster boarded. Now my celler ceilings are covered in black spots. What has gone wrong

 

On 2020-10-04 - by (mod) -

Michelle

Take a look at the diagnosis at THERMAL TRACKING BRIDGING GHOSTING - home

https://inspectapedia.com/interiors/Thermal_Tracking.php

On 2020-10-02 by Michelle

I’ve noticed dark lines across my ceilings in all rooms of the house. The house was built in 1998 with roof and wall insulation. I have a gas heater I use in winter and ducted a/c in summer.

The house does get window condensation in winter. I have had these marks for at least 5 years. I just had my roof restoration completed yesterday to address leaks, concrete cracks etc now thinking of maybe getting some Whirlybirds in the roof to help with ventilation.

What else would you suggest could help me with the ghosting? I really want to repaint my ceilings but need to address this ghosting issue first. Some ghosting is patchy and others show an outline of rafters in a grid pattern across the ceiling. Thanks for any help you can provide

On 2020-08-30 by (mod)

David

That could be a water leak or condensation or simply an air leak - just having to guess at this juncture.

I would pull down one of the trim rings, remove the bulb, and see if you can peer around the fixture to show me the condition of the edge of the ceiling drywall; we need first to assure there's not a water and mold issue on the upper side of the ceiling material.

On 2020-08-29 by David

Hi,
These dark stains appeared around several of our can lights. We got a new roof in February of 2020. These stains just appeared now in August ‘20. You can wipe the black stain off. When the new roof was put on many layers of old roof were removed. Could these stains be from thermal issues? Thanks.

On 2019-08-03 - by (mod) -

If your air conditioning equipment Us in the Attic you should check for a condensate pan leak

On 2019-08-03 by Anonymous

Last night we cut my ac rather low on 68 and I went into work and cane home and this was on my ceiling. Thermal tracking? Ghosting?

On 2019-12-21 by Karen

Looks like burn holes/blowout but no smoke smell where wall and ceiling meet. 3 Only on one side. Not visible in attic. This is a 10x10 raised structure built to code.

On 2019-09-09 - by (mod) -

Dee

Please see your stains and their cause and cure discussed at THERMAL TRACKING BRIDGING GHOSTING - home

as that's the most-likely explanation

On 2019-09-09 by Dee

Just moved into renovated home about 2 years. Year one noticed cracks in paint, was a flip so the paint was really cheap. Noticed a colored spot not sure what that could be. The house stated a new roof so not sure why we’re seeing the discoloration.

Should we be calling a roofer? See if it gets bigger? We’re approaching winter season.

On 2019-08-01 - by (mod) -

Leslie,

From your brief note we can't guess what the black substance comprising stains in your home is - soot, house dust, pet dust, or soot from a malfunctioning oil or gas fired heating appliance - this last item would indeed be dangerous as such malfunction can also mean release of dangerous, even fatal carbon monoxide into a building.

So start with the greatest safety concerns:
- what fuels are burned in the home? If oil or gas, have that equipment inspected for safety right away or if it is making odd noises, smells, or dispensing visible soot, turn it off immediately

On 2019-08-01 by Leslie

The black appearing substance . It is now on the windows appliances curtains.. I am concerned we are breathing this.

On 2019-05-27 - by (mod) -

Chad

At the CONTINUE READING links please click on the live link for GHOSTING DARK RECTANGULAR STAINS: CAUSES

and let me know what questions remain.

On 2019-05-26 by Chad

Hello. Just appeared on our walls and ceilings. Most are following joists and where walls meet ceiling. Few spots are on top of walls and extend to ceiling. What is it and what is the solution ? Thanks
IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2019-05-26 by Anonymous

IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2019-05-06 by Kim

Ok our family just moved into a rental. It's a newer build 2005 and we don't know the history of the house. We have notice what looks like brown/ black splatter all over the ceilings and even in the garage which is unpainted drywall. In the garage it's also on the windows of the garage door, shelving, etc.

The house has a stale smokey smell especially when it's humid. The humidity levels can get up to 90% (we have a gage) what can cause the spotting, and the high humidity?

I have asked our landlords and they don't know. They said we can just paint over it. I'm concerned that there is a bigger problem.
Also, the dryer vent runs up into the attic and out the wall. Could this be a problem??
Thank you for your help!

On 2019-03-28 - by (mod) -

THose could be thermal tracking but the fact that the stains are parallel to the eaves of the building rather than following the ceiling joists that almost certainly run in the other direction makes me think there may be gaps in insulation, leaks (which you don't think are there), or another moisture source in the roof space above. IT'd be worth getting access to the roof space and taking a closer look from above.

On 2019-03-27 by Scott

I've had these stains showing up on my ceiling for the last 3 years. I don't believe it's from a leaking roof. This pattern runs along both sides of the house. There are stains along the very edge, running along almost in a row. And then another row of stains about 3 feet out from the edge. Would this be an example of thermal tracking or ghosting?
IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2019-03-28 by (mod) - rectangular ceiling stains near exterior wall

Those could be thermal tracking but the fact that the stains are parallel to the eaves of the building rather than following the ceiling joists that almost certainly run in the other direction makes me think there may be gaps in insulation, leaks (which you don't think are there), or another moisture source in the roof space above.

It'd be worth getting access to the roof space and taking a closer look from above.

On 2019-03-27 by Scott

I've had these stains showing up on my ceiling for the last 3 years. I don't believe it's from a leaking roof. This pattern runs along both sides of the house.

There are stains along the very edge, running along almost in a row. And then another row of stains about 3 feet out from the edge. Would this be an example of thermal tracking or ghosting?

On 2019-03-08 by (mod) - can I cover black marks on my ceiling with paint?

Terry:

yes but diagnose the cause first.

In the end of the article CEILING STAIN DIAGNOSIS take a look at the discussion titled

Cures for Thermal Tracking Stains on Ceilings & Walls

On 2019-03-08 by Terry

Can I cover the black marks on my ceiling with paint if so can you recommend a paint

On 2019-02-08 by (mod) -

Thermal tracking is usually house dust not mold.

Read the details at CEILING STAIN DIAGNOSIS

On 2019-02-08 y Anonymous

I think my ceiling is with thermal tracking.

The thing is I'm really scared that I might be breathing in mold or something harmful to my health. I also don't have the money to hire someone that will help.

I'm so freaked out that I'm even sleeping in the living room. And I'm also afraid that the ceiling will cave in.

On 2019-02-08 by (mod) -

I'm not sure what we have in your photo, Ruth, it's a bit dark and blurry.

I think there may be a thermal tracking stain or a poorly-made drywall joint.

Please take a look at

Thermal Tracking: How to Diagnose Indoor Wall or Ceiling Ghosting Stains
found at

THERMAL TRACKING BRIDGING GHOSTING

On 2019-02-08 by Ruth

These are from my room's ceiling.

On 2019-02-07 by (mod) -

Ruth

I really would like to help you out but I can't see and don't know a thing about your building.

A line might be a simple stain (see Thermal Tracking in this article and others found by searching this site)
or
a more serious leak
or something else.

If a ceiling caved in and was actually falling drywall or plaster I suspect there were leaks (though of course there can be other causes)

On 2019-02-07 by Ruth

I've noticed this line across my ceiling about two weeks ago. The house is quite old and I'm concerned it will cave in (this happened many years ago and had to install new drywall). I suspect this is due to the problem I have with the AC unit as it's leaking. Please help

On 2019-01-24 by (mod) - moisture at ceiling at outside wall

Common cause of the problem you describe is an air leak into the ceiling combined with the accumulation of frost or ice under the cold roof.

As conditions change in the ice or Frost melt and shows up as a leak inside.

On 2019-01-24 by Phil

We constructed a new addition with a cathedral ceiling to our home four years ago and when it gets extremely cold and snowy outside we get moisture coming through the drywall where the ceiling and outside wall meet. what do you think this could be?

On 2018-10-30 by (mod) -

I would start with your home inspection report to review

- the condition of the roof: signs of wear or leaks

- Is the roof vented properly?

- nature of roof structure: is there a roof space at all? I suspect not.

Then I'd carefully dig into the stained area in the least-obtrusive area to begin determining if the stain is coming from indoor condensation on the ceiling or leaks from above. If there are leaks from above the ceiling panels probably need replacement, depending on the material.

If the panels are gypsum board and were wet on the hidden side they are likely to be moldy and to need replacement.

I might cut a test opening into the ceiling to inspect the ceiling side of the panel -particularly if it's drywall.

The other possibility is that these are soot stains from your fireplace - I can't enough of the stain pattern to have a confident opinion.

If the stains are soot, not mold you can probably clean and seal the surfaces and re-paint. But you may also have a fireplace draft problem that needs to be corrected: I would not use the fireplace before the chimney is inspected by an expert (chimney sweep) for safety.

So are the stains mold or soot or thermal tracking?

Determine by close visual inspection (I doubt that testing is needed) and see our articles "WHAT MOLD LOOKS LIKE" and also THERMAL TRACKING by searching InspectApedia.com using our on-page search box - to find those.

On 2018-10-30 by Abbie

Is there anyway you can tell me what I need to do with my cieling where do I start I just bought this

On 2018-10-30 by (mod) -

I would start with your home inspection report to review

- the condition of the roof: signs of wear or leaks

- Is the roof vented properly?

- nature of roof structure: is there a roof space at all? I suspect not.

Then I'd carefully dig into the stained area in the least-obtrusive area to begin determining if the stain is coming from indoor condensation on the ceiling or leaks from above. If there are leaks from above the ceiling panels probably need replacement, depending on the material.

If the panels are gypsum board and were wet on the hidden side they are likely to be moldy and to need replacement.

I might cut a test opening into the ceiling to inspect the ceiling side of the panel -particularly if it's drywall.

The other possibility is that these are soot stains from your fireplace - I can't enough of the stain pattern to have a confident opinion.

If the stains are soot, not mold you can probably clean and seal the surfaces and re-paint. But you may also have a fireplace draft problem that needs to be corrected: I would not use the fireplace before the chimney is inspected by an expert (chimney sweep) for safety.

So are the stains mold or soot or thermal tracking?

Determine by close visual inspection (I doubt that testing is needed) and see our articles

MOLD APPEARANCE - WHAT MOLD LOOKS LIKE and

also THERMAL TRACKING BRIDGING GHOSTING - home by searching InspectApedia.com using our on-page search box - to find those.

On 2018-10-30 by Abbie

Is there anyway you can tell me what I need to do with my cieling where do I start I just bought this [photo shown above]

On 2018-09-30 by (mod) - what causes crack to appear looks like ceilings falling down

Kelly, thank you for asking but also please forgive me; from just the text of your question I know so little about what we're discussing that I can't offer a useful answer.

If your ceilings are plaster (such as old plaster on wood lath) and are loose, they could indeed be falling and unsafe; But honestly I can't give a cause when I don't know what we're discussing.

You're welcome to try post a photo - or more than one, one per comment.

On 2018-09-28 by Kelly

Help what causes crack to appear looks like ceilings falling down

On 2018-06-04 by (mod) - problem could be a lack of insulation.

Yes the problem could be a lack of insulation.

You can probably buy an inexpensive moisture meter less expensively than renting one. You may want to hire a home inspector who has moisture meter as well as thermography or thermal scanning equipment.

On 2018-06-04 15:05:56.970308 by Anonymous

would blowing more insulation into the void spaces mitigate this? The room does get quite cold in the winter.

I will attempt, is it possible to rent a meter for this application?

On 2018-06-04 by (mod) - diagnosing blue stains on walls

I can't see much in the photo. But from Little I can see I would start by checking the moisture levels in the wall.

Why don't you scan across the wall area for variations in temperature and moisture. Let me know what You observe.

Also is it possible we're seeing:

Bleed through from something painted-over?

Thermal tracking or ghosting of wood lath - an old plaster-lath wall? That's suggested by the stain shape and spacing.

On 2018-06-04 by Anonymous

looking to find the cause of these stains, hopefully without opening the walls.

On 2018-05-19 by (mod) -

Dan that looks like roof eave leaks because the stains are so close to the outer wall and are closely spained together.

In concrast, usually we ascribe indoor stains to thermal tracking because of the regular spacing of the stains, suggesting tracking ceiling joists.

On your ceiling, the pattern, particularly that wide dark area would make me look both outside and in the attic for a roof leak or moisture or venting defect.

Painting won't prevent the recurrence. Dehumidification will help but it's best to find the underlying cause and fix that/

On 2018-05-19 by Dan

Is this ghosting and can I place a dehumidifier in this room? Will that prevent recurrence if I paint over it? Or must I take care of problem from roof?

On 2018-04-24 by (mod) -

In general the corrective measures for a thermal tracking are to clean the surface, paint the surface with a sealer, paint the surface with a finish coating.

And correct problems such as missing insulation, air bypass leaks into the ceiling or wall, and abnormal sources of indoor suit or dust such as an unsafe and malfunctioning boiler gas-fired heating system or smoking or use of scented candles.

On 2018-04-17 by Georgia

Thanks for your reply. What do you think my next move should be? Can I just paint over them?

On 2018-04-17 by Janet williams

I have a modular home built in 2014the ceil has black lines on ceil Joyce's and black on walls doesn't come off when you wash it.Dirty air has filter up the walls .

On 2018-04-03 by (mod) -

Looks like thermal tracking but if drywall tape is separating, if that is anywhere near the stains, I'd also look for a moisture or leak source above.

On 2018-03-29 by Jessica

Hi! Your article is very interesting and appreciated! I started noticing these strange dark spots on my ceiling and have found your post. Is this thermal tracking and if so, how do I remedy this?

I have the long streaks outlining the floor joists and a large spot on my cathedral ceiling just over my tv, which hangs above my fireplace.

I used the fireplace for the first time ever back in December, and again in January. The sheet rock tape in the corner of my ceiling is also starting to separate.
Thanks in advance for any help and direction!

On 2018-03-07 by (mod) -

Looks like THERMAL TRACKING - see that discussion inCEILING STAIN DIAGNOSIS

On 2018-03-07 by Georgia

Hi could you please help me I noticed these yesterday not sure what they are?

On 2017-09-05 by (mod) -

Hi Denise, I looked at your photos and said that I agreed that the long dark stain through the center of the room in what looks like an upper floor or cape-styleceiling looks like thermal tracking.

Beyond cleaning and painting, if you can see into that small roof-crawl space take a close look for a cause such as an insulation gap, duct routing or something that contributes to a temperature irregularity, probably a heat loss line across the ceiling.
Let me know what you find.

I also asked if this home a modular or was it stick built? Where is it located - country state province city (and thus climate) ?

On 2017-09-05 by Denise Muro

Based on reading your site we believe our lanai ceiling and exterior foyer ceilings are stained due to thermal tracking. Is the cause the same for exterior thermal tracking as interior, ie. missing insulation or is the cause different in exterior ceilings?

We want to repair the cause before having the ceiling repainted, we assume there is a crawl space access. This is a "builders" house about 1 year old. I have sent 2 photos via your email. Thank you.

On 2017-05-23 by (mod) -

You can send photos for comment using the page top or bottom CONTACT link to find our email.

On 2017-05-22 by Noel Biswas

How can I submit photos of damaged ceiling and walls for discussion?

On 2017-04-09 by (mod) -

You can send photos for comment using the page top or bottom CONTACT link to find our email.

On 2017-04-09 by John

What kind of expert should I ask? I could send photos? We keep a MOSTLY clean abode.
I'm uncomfortable taking the word of an insulation peddler.

On 2017-04-08 by (mod) -

I don't know, John. Phoenix is so hot and dry I'd not expect the usual explanation I give of ghosting to apply there.

But air currents everywhere do rise and curl against the ceiling, often depositing whatever's in the air onto the locations where there is velocity change or direction change.

I'd compare rooms, neighbors homes, and I'd look at sources of house dust and at air currents before spending a lot with the spray-foamer.

On 2017-04-08 by John

We have "ghosting" around the perimeter of the ceiling around most of the home. We had an insulation guy get up there and he said it was his opinion that the insulation was not present where the ghosting occurred. We are considering having foam sprayed to the ceiling of the attic.

We live in the Phoenix area (HOT & DRY), 22 year old home, could the lack of insulation really be the cause of this? The ghosting only appears on the ceiling, not the walls. Please reply to cellsat@msn.com if you can, I appreciate it.

On 2017-03-02 by (mod) -

Kim,

At the top of any inspectapedia page is a menu of main topic links including EXPERTS DIRECTORY - where you can find a home inspector who may be of help.

On 2017-03-01 by Kim Hill

Hi. You have finally answered what my dark joist lines are on my ceiling. thank you. However, how do I fix a high interior moisture, sources of dirt or soot, building leaks, etc.? Is there a specialist I can call? I appreciate your help.

On 2017-02-02 by Stewart Gates

We're recently noticed some brown spots on our bedroom and kitchen ceiling in a corner and along a strip over a window. The spots feel a little greasy. We live in a bungalow and have checked the loft which looks ok. Any idea what could be causing them?
Regards
Stewart

On 2016-11-19 by (mod) -

Interesting question, MIke. I'm not sure. It'd help to know the cause of the problem.

Where there any color differences at the ceiling joist locations before you painted? Had that area been cleaned, bleached, or primed differently? Or is there a significant temperature or moisture difference in that location.

Let's try to guess at what caused this difference before we "fix" it so that we don't just keep painting over and over.

On 2016-11-19 by Mike

After painting my ceiling I can see a whiter shade were the joists are. Why and can I correct it ?

On 2016-11-14 by Ruth

I am interested in learning how to get a consultation with your experts on grey ghosting/thermal tracking issues in my condo.

On 2016-08-24 by (mod) -

Condensation might cause mold in a building; (not mildew as that only grows on living plants). I'd ask what's different between the recent stain appearance and the preceding decades. I'd also look more closely at the roof leak question. Roof leaks can be tricky to track down. A moisture measurement around the stain area might be informative.

On 2016-08-21 by Shelly

I have vaulted ceilings in living room and had discoloration area start over the front door area middle of ceiling . Another new spot on opposite wall center and near fireplace. Roof checked and no leaks. Roofer thinks possible condensation causing mildew and recommended roof vents for this area.

Agree it looks more like a mildew as its not in steaks but rounded area. Open for thoughts or suggestion. House is 31 & same areas had paint fall off after 20 years. Celine's have been scraped, primed, painted approximately 10 years ago.

On 2016-07-26 by (mod) -

Possibly. Look for the characteristic pattern we describe above.

On 2016-07-26 by Marty

My wife and I just purchased a townhome. We have been in it for about two months. Today I noticed a grey area on the wall. Could this be ghosting?

On 2016-06-03 by (mod) -

Stephanie, before paying for an inspection take a look yourself at our description of thermal tracking stains; if that's what you have, in the article above you'll find a live link to details about what to do in this sentence

See GHOSTING DARK RECTANGULAR STAINS: CAUSES for more examples of ceiling stains caused by poor insulation and/or air bypass leaks.

Or search for that capitalized article title to find it via searching InspectApedia.com

You can call a home inspector to help diagnose stains;

If you are pretty sure you have outside roof leaks you can try calling a roofer, though they don't like to do small repair jobs so you may have to resort to a handyman;

if the latter, be sure your handyman actually knows how to repair roofs properly - ask his or her roofing experience.

On 2016-06-03 by stephanie

what type of service provider can I call to have the sooty stains n my ceiling looked at? I suspect water damage from small roof over bay window. Do I call a roofer? General handyman?

On 2016-05-25 by Kathleen

New roof installed last year no apparent leaks or reason for ghosting on every ceiling. What could possibly be the cause

On 2016-04-25 by Korkie

I have massive 'ghosting' on my bedroom ceiling. What type of diagnostic agency should I call to verify the cause of these stains, and assure me they are not mold related? Most important, to repair whatever is causing this ugly situation.

On 2015-07-17 by (mod) -

Kim the dark stain may have already been present but not noticed before, or it could be new. If new, and if new A/C equipment is installed above that area I would look for a leak in the condensate handling system.

On 2015-07-17 by kim

have recently had reverse cycle air conditioners installed, last week. Above the inside unit there is a dark appearance on the ceiling. I never noticed it at first only over the last 2 days. What could it be. Thanks

Question: how long does ghosting take to appear?

(Jan 30, 2014) how long does ghosting take to appear? said:
can ghosting result from a single event such as a brush fire in the area or unseeing my fireplace just once. Or is it something that takes a longer period of time and/or multiple incidents?

Reply:

How long ...

Yes I think that given the right conditions - cool moist wall areas and high levels of airborne soot - we could see ghosting from a single event.

On the other hand, on occasion we've found folks absolutely convinced that a stain was new when research showed that it was there before but just not noticed. Once something is called to our attention it seems blatant.

Usually thermal tracking or ghosting stains take months to years to become quite evident but really it depends on the combination of

• indoor airborne particle levels
• indoor moisture sources
• building insulation and thermal breaks in the insulating blanket
• outdoor temperatures and building heat loss rate
• other factors I've not though-of to name

Question:

(Nov 27, 2014) Doc said:
need to know if these are thermal tracking. They are on our kitchen ceiling and above that is a hallway on the 2nd floor.

Reply:

Dunno Doc, I can't see a thing.

Question: moisture meter vs. nearby industrial plant

5 Feb 2015 G.Gardner said:
I live on the top floor of a private house. I have shadows on the ceiling along the exterior walls in my bedroom.

I have gas heating baseboards. Now I see these shadows on other parts of the house on interiors ceiling not over the heating units, and along some areas right over the baseboard heating.
I just had an Insurance adjuster was just here checking out a roof leak, he tested shadows for moister and the meter read no moister. He then ask if I have an industrial plant nearby. I do.

Reply:

First, a moisture meter can show no leaks but the building could have had leaks previously that happen to be "dry" at the time of testing; so relying on a meter alone is unreliable.

Second: in the More Reading article list above, please take a look

at THERMAL TRACKING BRIDGING GHOSTING

- since what you describe sounds like that phenomenon.

You'd want to look at: insulation, moisture levels, dust sources. Even common house dust or smoking or candle soot or fireplace soot or oil burner soot can leave these marks; you don't need to live next to a soot-producing industry.

If the nearby industrial plant you cite is however the main particle source you'd be more or less affected depending on how much outdoor air is circulated in your apartment (e.g. you keep windows open or blow outdoor air into the living space).

If absolutely necessary one could collect a surface tape sample and have the particles analyzed to see if your marks come from the plant or from normal house dust.

On 2013-01-10 by Anonymous

Toni,

In addition to checking the attic insulation and ventilation as we discuss in this series of articles on ghosting, ask your heating service tech or chimney sweep to check both the operating condition of your heating equipment (it may be producing indoor soot) and the chimney.

Dan Patch:

The stain pattern you describe suggests thermal tracking or ghosting.

Kevin,

Interesting question; we'd need to know more before having much confidence in a guess; But one remedy to try is painting with a lacquer primer sealer. Other types of primer/sealer paints, even high quality "stain hiding" paints, may not be impervious to oil type & some other types of stains that can bleed through latex.

On 2012-11-24 by Toni M.

I have a boiler and hot water heat. I've noticed when i start the heat in colder months I get black stains on the walls mostly above the vents. What causes this? I can't keep painting!

On 2012-10-27 by Dan patch

I installed a Hepa Filter in my furnace and now I have dirt spotd on all the ceiling rafters and sheet rock nails and at the attic floor line.

On 2012-04-06 by Kevin Margolfo

We have a greyish stain in a ceiling that was completly sanded down, applied two coats of a high quality primer/sealer, then mixed paaint with spray texture and shot ceiling. Stain was not there after sealing ceiling. Everyone cannot figure out what the stain is, even paint supplier. Stain is about 7" round. We have been doing ceilings for 35 years.

On 2012-03-08 - by (mod) - how can I clean soot tracking on ceiling and wall?

Brian, you can use any household cleaner that doesn't also take off your paint, or a heavier-duty detergent such as a TSP substitute. Search InspectAPedia for "STONE CLEANING METHODS" to see a reference to a phosphate-free TSP type cleaner.

But in my experience you may find that you need to re-paint the soiled surfaces. Before going to that expense

- have your heating system serviced and chimney(s) inspected to be sure you've stopped soot production in the building; in particular soot production from gas fired equipment is a sign of DANGER - so you should look into this ASAP and meanwhile be sure you have working smoke and carbon monoxide detectors in your home

- consider giving up on the use of scented or other sooty candles.

On 2012-03-08 by Brian

After reading the post I have determined that I have soot tracking from a gas furnace as well as from candles. I'm sure my insulation isn't the best but it is what it is. What is the best way to clean the ceiling and the wall before I re-paint.

On 2011-12-21 - by (mod) -

Allan, for more space I've answered your stain question at CEILING STAIN DIAGNOSIS FAQs . Send us some photos if you can, and if the explanation leaves more questions, just ask. DF

On 2011-12-21 by allan

after a major snowstorm last week, and 2 week power outage, i see soot stains on the ceiling and walls, with many soot spots, near a ceiling AC return vent. The AC compressor and air handler are unplugged and not working since the fall, so no air should be moving through the vent. Is it possible that somehow air came out of the vent, carrying with it soot from the AC ducts?

...

Continue reading at CEILING STAIN DIAGNOSIS - topic home - or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• CEILING STAIN DIAGNOSIS
• GHOSTING DARK RECTANGULAR STAINS: CAUSES
• HEAT LOSS in BUILDINGS
• MOLD APPEARANCE - WHAT MOLD LOOKS LIKE
• STAIN DIAGNOSIS on BUILDING INTERIORS - home
• THERMAL TRACKING BRIDGING GHOSTING - home

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CEILING STAIN DIAGNOSIS FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING STAINS

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