Attic or cathedral ceiling mold cleanup: how & when to remove roof mold contamination.

Do we need to remove the roof or perform other demolition to clean or remove attic, cathedral ceiling, or other roof cavity mold contamination? Here we explain when a roof tear-off is justified as part of an attic or roof mold cleanup project (rarely) and when roof tear-offs are not justified.

This document gives advice on how to find and deal with mold in building attics and roof cavities. This procedure helps identify the presence of or locate the probable sources of mold reservoirs in buildings, and helps decide which of these need more invasive, exhaustive inspection and testing.

ATTIC MOLD When to Tear Off the Roof

How does one determine if the roof should come off to remove attic mold contamination?

Toxic attic mold: The photo at the left was identified as a toxic mold that probably should be removed, although the ease of movement

Generally, tearing off a roof and roof sheathing and perhaps roof framing, to remove mold would not be sensible nor cost-justified.

Mold growth, provided it is not just cosmetic mold which can simply be left alone, can be cleaned from wood surfaces by blasting, scrubbing, or even simple surface wiping, depending on the surface accessibility and smoothness.

Lots of protruding nails through a roof deck preclude wiping or scrubbing the roof decking surface and media blasting might be appropriate in some situations.

Watch out: do not launch a costly attic or under-roof mold cleanup job for harmless or cosmetic mold growths. See ATTIC MOLD, HARMLESS COSMETIC? for details.

Do We Need to Sand or Blast the Roof Surface to Remove Mold?

Sanding wood building surfaces such as plywood or tongue and groove roof sheathing, wall sheathing, or wood framing is usually unnecessary and inappropriate.

Furthermore, sanding a roof deck is almost impossible because of the interference from protruding nails. Media blasting (below) works on these surfaces.

If you must return wood surfaces to immaculate, pristine looking condition, perhaps for cosmetic reasons where wood surfaces are left exposed to view in a building interior, see

MOLD CLEANUP by MEDIA BLASTING and

MOLD CLEANUP with BLEACH and

MOLD CLEANUP - WOOD FRAMING & PLYWOOD and finally

MOLD CLEANUP HEALTH RISKS

Do we have to sand or clean moldy wood to remove all traces of mold stains?

No. Any stains that remain on wood surfaces after cleaning are harmless (usually sterile hyphae remaining below the wood surface).

Fixing the cause of mold is an essential part of any mold cleanup job

At the time of cleaning off mold, it is essential that the cause of mold growth be corrected as well, or mold growth will probably return, regardless of whether any stained surfaces were left from the prior cleaning.

Should I use a biocide or fungicide during roof mold cleanup?

Use of fungicidal encapsulants may reduce but not eliminate the risk of future mold growth, primarily, or more lastingly because such encapsulants reduce the future uptake of moisture in the wood materials.

Fungicidal chemicals themselves can be expected to break down over time and should not be relied on as "mold proofing".

See these articles for details on using mold sprays, fungicides, coatings, encapsulants in attics

FUNGICIDAL SEALANT USE GUIDE

FUNGICIDAL SPRAY ADVANTAGES

MOLD SPRAY WARNINGS

DISINFECTANTS, SANITIZERS, FUNGICIDAL-SEALANTS SOURCES

MOLD CLEANUP - MISTAKES to AVOID

In our roof interior (attic) photo at left you can see antique roof framing along with black stains and probably some mold growth from a long history of roof leaks. Even in this case, in our OPINION the reasons to remove and replace roof sheathing and framing would normally be based on the condition of the roof framing and sheathing, not on the presence of mold or stains.

We remove mold from roof framing and sheathing;

We replace rotted or unsafe roof framing or sheathing, combining that work with a new roof covering as well.

So when is a Roof Tear Off Necessary if I've got a Moldy Attic or Cathedral Ceiling?

When the roof sheathing is rotted or damaged, or when other structural repairs are needed, a tear-off is unavoidable.

When attic surfaces or insulation contain a large reservoir of toxic or allergenic mold, AND if the area were inaccessible, say because the space is too small to enter, then it may be necessary to remove some portion of roofing to give access for remediation, particularly if there is evidence of transmission of problem mold from that space into the living area.

This article is part of our series: MOLD in BUILDINGS which describes how to find mold and test for mold in buildings, including how and where to collect mold samples using adhesive tape - an easy, inexpensive, low-tech but very effective mold testing method.

See TEST KIT for DUST, MOLD, PARTICLES: INSTRUCTIONS for details.

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2019-08-1 by Art

Hi, i have done extensive work battling mold in my home and I'm at my last step and need your professional opinion.

Half of my very low pitched roof had extensive black mold that was causing numerous health symptoms. I had the roof sheathing replaced. I had the ventilation and insulation problems fixed a year before this year off and therefore all of that mold was dried. I also sanded down the raftets while they were exposed and encapsulated them in elmers glue and water mixture.

I became very symptomatic after this tear off and feel the symptoms the strongest on the second floor. We have cleaned the house but we will clean it again with better detail.

My question is this; do you think that when the moldy sheathing was torn off and i sanded some of the rafters that some of that mold landed on my sheeps wool insulation on the Attic floor and is causing those symptoms?

Since that insulation was quite expensive it would hurt to run-over it but my and my family's health is priceless. Thank you for your help

On 2019-04-02 by Artie - contractor says they never treat mold

They told me that the sheeting needed to be taken off in order to get to the area between the sheeting and the rafter.

They said that it would not do any good to treat the mold that can be seen if you are going to leave what is trapped between the sheeting and the rafters. I have had others say that if things are corrected and the moisture problem taken care of, the mold should not continue to grow and therefor those areas are not critical.

This is my first experience with mold and it seems that many people have many different ideas. I am not sure how bad the one area is as it is pretty black but the rest of the attic just has spot mold and there do not seem to be any large community areas where it is all black with the exception of the one area.

I have heard that remediation can run $10,000 which would buy a considerable amount of sheeting. Since they said it had to come off anyway, I thought it would be just as good to remove it, put on new, fix the venting, and move on.

I had a contractor tell me today that in his 30 years of replacing roofs, they have never had to treat the mold.

They replace the sheeting and fix the ventilation and they have never had an issue again. Obviously do not want to spend more than I need to. Appreciate your guidance.

On 2019-04-02 by (mod) - clean and seal, don't take apart the roof structure

Alternatively leave the structure in place, clean the exposed surfaces, apply a sealant with care; if the areas are dry and not rotted it may not be cost justified to do the tear down suggested.

See OTHER PEOPLE's MONEY https://inspectapedia.com/home_inspection/Other_Peoples_Money.php

Naturally I can't SEE your attic nor the conditions there.

On 2019-04-01 by Artie - black mold in my attic due to a leak

I have black mold in my attic due to a leak and the insulation contractor blowing insulation out to the edge covering all my roof vents.

Since remediation is not cheap and some of the sheeting needs to be replaced anyway, if I have ALL of the sheeting replaced and fix the ventilation issue do I still need to have remediation done?

On 2019-04-02 by (mod) - I have black mold in my attic

With the warning that

1. not all "black mold" is harmful (search InspectApedia.com for COSMETIC BLACK MOLD) but indeed if mold grew or is growing in your attic following a leak or other wet conditions it probably needs some cleanup

2. but don't just look for "black mold" - plenty of other molds are very harmful but NOT black in color


Why would you be replacing roof sheathing if it's not rotted.

Clean, seal, fix the leaks and fix the venting.

Keep in mind that if there is harmful mold in your attic your insulation probably needs to be replaced too. But as you just saved a complete roof tear-off that ought to seem cheap in comparison.

On 2018-08-11 by Tyler - buying a house, attic spaces look mold

We were about to buy a house which had one of the attic spaces looking moldy. I have attached photos here.

Should we require the seller to clean it all out, repair the entire roof, or run the other way?

Help! We don’t want to move into a house that needs a new roof! [photos lost by Comment Box]

On 2018-08-11 by (mod) - buying a house with a moldy roof: what should we require the seller to do?

Tyler


My comments are limited to the one photo that is a miniscule fraction of the information one would gain with help from an on-site expert (not to mention that there could be other pressing, costly topics that need to be addressed)

IF the seller agrees to any responsibility for the conditions shown in your photo, in my opinion you'd be better off taking an allowance and doing the necessary work yourself.

That way you won't face having to re-do the work later because short-cuts were taken, and it's better for the seller as they avoid any subsequent liability for work that they undertook in your behalf.

The possible concerns to be addressed are:

- damaged roof sheathing that may need replacement now or when re-roofing

- moldy roof sheathing, an unlikely but not impossible source of airborne problematic (allergenic or other) mold in the occupied space

- mold-contaminated insulation

- inadequate, blocked, or improper under-roof ventilation

All of those should be addressed. But scheduling any actual repair work would be smarter if it considered all work that the home needs.

On 2018-03-29 by Wendy - where to start if there's mold in the attic

We bought a ranch-style home and retired to the lakes region of Maine in 2016, knowing there was a high water table because previous owners had an extensive water system in the basement, which kept it dry. However, what we didn't know was that the person who owned the house had only remodeled the house on the surface.

Our first winter here, we had no problems (that we knew of), but this winter (2018), we had a couple of issues with ice dams and water leaking under the shingles and into the ceiling

. When it was investigated, my husband found that the the blown in insulation was blocking the vents, the bath exhaust fan hadn't been vented outside the attic, and that the sheathing was extremely wet.

There appears to be some kind of mold up there, but there is no access to the attic due to a very low pitched roof. The bathroom fan has been replaced and is now vented properly, but we need to know where we go next.

Neither of us have had any ill effects from mold, but we're still concerned about it, and need to know what type of company we should call to find the extent of the damage and repairs needed, but don't know where to start.

On 2018-03-29 by mod -

I recommend reading

• ATTIC MOLD - home
  • ATTIC MOLD IS A PROBLEM ?

On 2017-12-08 by Liz.Allen - re-roofing job made us sick

We are receiving a new roof and we are all sick. Can it be from stirring up black mold?

On 2017-12-08 by (mod) - is our new roof stirring up mold and making us sick?

Liz

I don't know. But I can pose a couple of questions that might be helpful.

First, have you discussed your sickness with your doctor to ask if it appears to be environmentally related or mold related?

Second, was there a significant area of mold contamination in the Attic of your home that might have been disturbed by pounding on the roof during a reroof operation?

Third: we don't know what is your illness, we don't know if it could be related to dust or debris stirred up during roof work: start by asking your doctor for help sorting out the illness nature, cause, and thus remedy

On 2017-07-17 by RON SAMSEL P.E. - what to think about black mold on roof trusses

Recently inspected an attic and roof. The attic is truss framed with plywood sheathing. The white blown in insulation was used. On the east side only there is 'black mold" for the first 6' up the slope. The roof has baffles at alternating thusses, soffit and ridge vents.

The black mold is on the first 3 truss panels; skips a few trusses and reappears on the next panel or two. At the south end of the roof, the ridge changes direction causing an overlay condition. A 10' x 10' area of plywood has been removed to provide air into this area.

The gable end wall on the east side is totally black while nothing is visible on the west. A few panels were noted to have the mold starting.

At the intersection of the plywood overlays, the upper sheets contain black mold spreading about 2-3' up the slope. From the outsidethere are a couple of dips in the plywood which appear as though thes areas were loaded with shingles during re-roof.

It also dips along the edge where the moldy plywood exists. The roof is only 2 years old according to the roofing receipt.
have you ever seen such a condition, or do you have any reasonable explaination why only the east side; first 3 truss spaces then skip, etc.

If you have any idea, I would appreciate any help you might offer. Ron

On 2017-07-24 by (mod) - moisture & mold under roofs won't be uniform

Ron,

Mold likes to grow where there's moisture on mold-friendly surfaces.

Moisture may indeed be unevenly distributed under a roof depending on exactly how air is moving - variations in baffles, insulation, wind direction, soffit openings, ridge openings, blocking, etc. all cause those effects.

Even variations in the surface coating on wood may be in effect as will roof exposure to sun vs shade.

Your description sounds like a classic case of inadequate under-roof / attic ventilation and moisture or even ice dam leaks at the lower roof eaves.

Watch out: don't just look for black mold or you will miss most of the most harmful mold contaminations in buildings

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Continue reading at ATTIC MOLD ENCAPSULANTS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• ASPHALT SHINGLE RE-ROOF GUIDE
• ASPHALT SHINGLE REMOVAL TOOLS
• ATTIC MOLD - home
• ATTIC MOLD CAUSES
• ATTIC MOLD IS A PROBLEM ?
• ATTIC MOLD - IS IT TOXIC?
• ATTIC MOLD, WHERE TO LOOK
• ATTIC MOLD, WHAT IT LOOKS LIKE
• ATTIC MOLD, HARMLESS COSMETIC?
• ATTIC MOLD ROOF TEAROFF
• ATTIC MOLD ENCAPSULANTS
• MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD

 

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ATTIC MOLD ROOF TEAROFF at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to MOLD CONTAMINATION & REMEDIATION

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