How often do you go up into your attic? Have you ever been up in the attic if it is only accessible from a small hatch in your bedroom closet ceiling? When you go up in the attic once a year to get holiday decorations or to switch out seasonal clothes, do you notice the wood on the roof is discolored? Have you seen frost on the roof nails or roof sheathing in the winter?

Attic mold problems can range from small areas surrounding a bathroom fan vent that became disconnected to large scale mold growth covering the entire side of the roof because of a ventilation problem. Typically, ice dams do not cause large scale attic mold problems. The ice dam water comes in low down on the roof edge and ends up in your ceilings and walls. Gravity does a great job of forcing the water down into your home rather up onto roof materials. Ventilation problems can range from missing or blocked soffit vents, a shingled over ridge vent, too many types of ventilation (more ventilation is NOT better in an attic if the different systems conflict with each other), or no ventilation at all (spray foam insulation sealing up the attic). Even if there is adequate ventilation, if bathroom fans are not vented properly outdoors, steamy air released into a cold attic in the winter can lead to condensation, resulting in mold growth.

Does mold growth in the attic mean there is a mold problem throughout the house? Absolutely not. Attic mold is in the attic because that is where the moisture is. Your home does not have the same environmental conditions as the attic (at least it shouldn’t!) Mold grows on wood roof materials when they become damp from condensation or roof leaks. Unless you have an HVAC system in the attic or go into the attic often and leave the pull-down staircase open, the mold will remain in the attic.

The main reason to professionally remediate attic mold is for property value and if you are selling the house. No one wants to buy a home with mold covering plywood roof sheathing. Even if the mold is contained in the attic, it is not a desirable characteristic for a potential buyer and could lead to larger, more expensive problems. The mold is a living, growing organism that will continue to grow if the moisture source is not resolved. Molds are decomposers, meaning they ‘eat’ whatever food source they are growing on as long as there is enough moisture. In other words, the mold is eating away the wood roof materials. Now, it may take 100 years for the mold in your attic to decompose a piece of plywood, or it could take just a few years if there is a major condensation problem that occurs every winter.

Identifying the extent of the mold problem and the moisture source that caused it is important to manage the situation. If the mold growth is professionally remediated but the moisture source is not resolved, mold will simply regrow on the remediated wood. No product on the market today, no matter what the company claims, can prevent mold from re-growing on remediated wood if moisture continues to accumulate.

Once the moisture source is identified and resolved and the mold professionally and successfully remediated, mold growth should not recur. Remediation involves several steps in an attic and will not be considered successful until remediated wood has been tested and visually inspected. Current industry standards state, and common sense dictates, that once an attic is remediated, there should not be any visual evidence of mold remaining. When I go into a newly remediated attic and I see moldy wood, the client gets the unfortunate news that the remediation process failed, without even having tested the wood. In this situation, I often get told a statement like ‘the remediation company said they killed all of the mold so what’s left is just staining’. This is simply not true. In 22 years of mold inspections, I have not once found attic mold ‘staining’ to be just that after remediation. The discoloration is confirmed by sampling to be mold that was not fully removed by the remediation company.

The use of a white sealant/paint over remediated wood is also not acceptable; this is to protect the homeowner from companies that paint over the mold with a thick, white coating of paint that is called an ‘anti-microbial’ product, which ‘kills’ the mold. This statement is false. All the white paint has accomplished to do is cover (hide) mold the remediation company failed to remove in the first place.

In summary, attic mold is something to take seriously, especially if the attic is used for storage or you are planning on selling the house. Remediation is painstakingly hard work and involves old fashioned elbow grease. There is no chemical fog or spray or paint that will remove the mold by itself. The mold must be abraded off the surface of the wood materials, the wood tested to be sure the mold has been successfully removed, and any/all moisture sources identified and resolved to prevent the mold from coming back.