Attic Mold Removal in Boise, ID
Dark growth on the underside of the roof sheathing, cleaned under containment, with the wet insulation out and the reason it got wet written down. We clean and dry the attic. Roof repair is a roofer's scope, and we coordinate it.
- 24/7 emergency response
- IICRC certified · RCE-67387
- Locally owned · 10 years
A person answers 24 hours a day
Dispatching to Boise within about 90 minutes.
Call Now: (208) 391-5248Arrival windows are estimates from our South Nampa dispatch, not guarantees. Call and we’ll give you a real time for your address.
What the work involves
The actual scope, in the order it matters. If a step is missing from someone’s bid, ask them why.
- Find the moisture: a bath fan or dryer vent ending in the attic, blocked soffit vents, missing baffles, an unsealed hatch or can lights leaking warm house air, or a roof penetration. In an Idaho winter that warm, damp air frosts on the cold sheathing and melts in February.
- Containment at the hatch and negative air exhausting outside, so nothing disturbed in the attic reaches the rooms below.
- Removal of insulation that is wet, matted, or sitting under the affected area. Blown-in insulation that got wet does not dry in place, and it holds water against the ceiling drywall.
- HEPA vacuuming and cleaning of sheathing, rafters, and trusses, with sanding or media blasting where growth has gone into the wood. Antimicrobial after cleaning where the scope calls for it.
- Drying of the attic assembly with readings on the sheathing until it matches unaffected wood in the same attic.
- The list of what has to change so it stays dry: fan ducted through the roof or gable, baffles installed, hatch sealed, ventilation corrected. Some of that is ours, some is an HVAC or insulation contractor, and the roof itself is a roofer. We say which is which.
- New insulation blown back once the sheathing is dry and clean, and photos numbered to the report.
Half of what fixes an attic is not our trade. We do not replace roofs, and we do not sell or install HVAC equipment, so the new bath fan, the duct run through the roof or the gable, and the deck itself all belong to a roofer, an insulation contractor, or an HVAC contractor. What we hand you is a written list of what has to change and whose trade each item is. Cleaning the wood without that list is a two-year fix.
How the job runs
The same sequence on every loss. Knowing what happens next is most of what makes the first day survivable.
Find out why the attic is wet
Attic mold in this valley is rarely a roof leak. It is house air. Warm, moist air from showers, cooking, and people leaks up through the ceiling, hits roof sheathing that is below freezing in January, and frosts. In late February it melts and the sheathing stays wet for weeks. A bath fan blowing into the attic instead of through the roof does the same thing every morning. We find the path before anything is cleaned.
Contain
Poly at the attic hatch, the hatch used as the airlock, and a negative air machine exhausting through a gable vent or a window below. Attic work disturbs insulation and dust along with the growth, and the ceiling has dozens of holes in it: can lights, fans, plumbing vents. Containment keeps all of it out of the bedrooms.
Remove what will not clean
Wet or matted blown-in insulation, and any insulation directly under the affected sheathing. It comes out by vacuum through the hatch, bagged, not carried down the hall. Sheathing that has delaminated or rotted through is a roofer's replacement, and we mark it for them.
Clean the wood
Sheathing, rafters, and trusses are HEPA vacuumed, then cleaned. Growth that has gone into the grain of the sheathing is sanded or media blasted. Spraying an attic without cleaning it first is why it comes back the following spring.
Dry and verify
Readings on the sheathing at marked points until it matches dry sheathing elsewhere in the same attic. Photos numbered to a sketch. If a sale or a lender wants clearance sampling, an independent inspector takes it and the lab sends the result to you.
Fix the air, then insulate
Fan ducted outside. Baffles at the soffits so the insulation stops blocking the intake. Hatch and can lights sealed. Then new insulation goes back. If the fix belongs to a roofer or an HVAC contractor, we coordinate so the attic is not sitting open between trades.
A person answers 24 hours a day.
Your job page
Every job gets a private page you can open from your phone. What we found, what’s running, and what happens next, updated as we work rather than when you call to ask. Documented while it happens, not after.
- Job page
- Your private link: status in plain language, photos, documents, and the next step on the schedule.
- Photos
- Numbered and dated, tied to the job record, the same set your adjuster gets.
- Paper trail
- A written scope and estimate in the format adjusters and property managers expect, handed over with the complete file.
When to call us
If one of these is your situation, the clock matters more than the diagnosis. Call first; we’ll sort out the rest on the phone.
- You went up for the holiday boxes and the underside of the roof is dark or speckled, usually on the north side and near the eaves.
- A home inspector photographed attic mold and you are mid-transaction.
- The bath fan or the dryer vent ends in the attic, and you found frost or drips up there in January.
- Ice dams wet the insulation last winter and nobody pulled it.
- There was a roof leak, the roofer fixed it, and the insulation under it is still matted.
Not sure which one you have? Call and describe it.
What we see in Boise
Field notes on Boise: the housing stock, where the water comes from, and what that means for this work.
The North End and East End are largely pre-1940: galvanized supply lines that have been narrowing for eighty years, unlined crawlspaces, and balloon-framed walls that let water run from an upstairs bathroom down to the sill plate before it ever shows on a ceiling.
Warm Springs Avenue and the blocks around it are on the Boise Warm Springs Water District line. Geothermal water heats those houses through original piping. A failed fitting there is a hot-water loss inside a hundred-year-old wall cavity, which pushes both the drying plan and the microbial risk in the wrong direction.
Bench homes are mostly 1940s–1960s ranches on shallow crawlspaces: eighteen inches of clearance, often no vapor barrier at all, and a roof-mounted evaporative cooler over the hallway. The cooler line is a call we take every spring when it's charged for the season and again every fall when it isn't drained.
Southeast Boise and the Barber Valley / Harris Ranch side sit close to the Boise River over a shallow water table. Crawlspaces there stay damp straight through irrigation season. When someone from that part of town calls about a smell, the answer is usually ground moisture coming up through a torn vapor barrier. No pipe involved.
Downtown and the mixed-use blocks put the loss on somebody else's ceiling. A supply failure on the fourth floor is a four-floor job by the time we're on site, and the moisture documentation has to hold up for multiple tenants and one carrier.
Working across:North End, East End, Boise Bench, Southeast Boise, West Boise, Harris Ranch, Downtown
Questions we get
Straight answers, including the ones that occasionally talk someone out of hiring us.
Why does an Idaho attic grow mold in winter, not summer?
Frost. House air carries moisture from showers, cooking, and people. It leaks into the attic through the hatch, can lights, and any bath fan that was never ducted outside. When the roof sheathing is below freezing, that moisture frosts on the underside of the roof. In late February and March it melts, and the sheathing stays wet for weeks while the attic is still cold. Summer attics here are hot and dry. The damage is done by spring.
Do the dark stains have to come off the sheathing?
Cleaning removes the growth. It does not always remove the color, because the pigment is in the wood fibers. Sanding or media blasting lightens it, a stain-lightening product can reduce it further, or it can be left once it reads dry and clean. For a sale, what a buyer's inspector reads is a moisture meter and, if required, a clearance report from an independent inspector, not the shade of the plywood. We tell you before the job which option the scope includes and what it adds.
Can I just spray the attic with a mold killer?
A spray kills what it touches on the surface and does nothing about the moisture that caused it, so in an attic that frosts every January the growth returns the next spring. Sprayed over uncleaned growth, it also seals the spores in place. Attics are a bad place to work without a plan: no floor, low headroom, loose insulation, and dust that goes down through the ceiling. A small patch, in an attic where the bath fan has already been rerouted outside, is a reasonable weekend job. The ducting is the part that decides whether it comes back.
Does attic mold need to be removed before I sell?
Nothing requires it before listing, but it will come up. A buyer's inspector will photograph it and ask where the bath fan goes. Known problems belong on the seller's disclosure, and how the form words that is your agent's trade, not ours. Most sellers would rather clean it and fix the source on their own schedule than negotiate it off the price with two weeks left.
Do you fix the roof?
No. Our part of an attic job is the cleaning, the drying, and the insulation that goes back. A deck that has delaminated or rotted through gets marked on the sketch for the roofer, and we work around their schedule rather than pulling equipment and coming back twice.
Does insurance cover attic mold?
Coverage follows the cause. Mold from a sudden covered event, like a roof opened by wind or an ice dam that forced water in, is often covered up to a mold sublimit. Mold from a bath fan venting into the attic for eight years, or from winter condensation, is a maintenance issue and generally is not. The source goes in the report either way, with the photograph behind it, so you know what you are actually asking the adjuster for.
How much does attic mold removal cost?
It is priced on square footage of affected sheathing, how much insulation has to come out and go back, whether the wood has to be sanded or blasted rather than cleaned, and access: a walk-up attic and a scuttle hole over a closet are different days. Fixing the source is usually a separate line, and some of it belongs to an HVAC contractor or a roofer. The scope comes back as line items with the sheathing readings attached, and you read it before anyone opens the hatch.