Smoke Odor Removal in Minnesota

The walls are clean. The carpets are new. It is October, the furnace runs for the first time since spring, and the whole house smells like the fire again.

That is the call we get most often, and it is almost never a cleaning failure. It is a sequencing failure. Somebody treated the air before removing what was producing the smell, and the treatment wore off while the source stayed put. Smoke odor removal done in that order never holds.

Smoke odor removal only works in one order. Kiser Construction has been doing fire and smoke work in the northwest metro since 2003, and this page explains what that order is and why the shortcuts do not hold.

Is this the right page?

This page is about odor. If you are dealing with visible soot marks and staining, go to soot removal, which covers what soot does to materials and how it comes off. If the fire was recent and you need the whole scope handled, we do fire and smoke restoration across the Twin Cities north metro.

Why the smell comes back in the fall

Smoke odor is caused by residue that is still in the building. Whether you can smell it on a given day depends on temperature and humidity.

Warm air holds more of those compounds and moves them around. Cool dry air holds fewer. So a house that smells fine in a Minnesota February can smell strongly of smoke the first warm week in May, and again in October when the furnace comes on and pushes heated air through duct work that was never cleaned.

Heat is the tell. If the odor tracks with the heating system or the weather, there is still source material in the building. Air fresheners and time will not resolve it, because nothing has been removed.

Where the odor is actually living

• Inside duct work and on the furnace blower
• Attic and wall insulation, which is porous and holds a great deal
• Carpet pad, even under replaced carpet
• Unsealed framing, subfloor, and the back side of drywall
• Inside cabinets, closets, and any enclosed space that was not opened during cleaning

That last one catches people. Rooms get cleaned and closets get skipped, and a closet is a small unventilated box holding fabric.

How professional smoke odor removal works

Order matters more than product here.

1. Remove the source. Porous material holding odor comes out. Nothing else works until this is done.
2. Clean every hard surface, including inside cabinets and closets.
3. Clean the duct work and replace filters.
4. Seal remaining porous surfaces such as framing and subfloor with a sealing primer.
5. Treat the air last, once there is nothing left feeding it.

Companies that start at step five get a house that smells fine for three weeks. That is the cycle most people have already been through once by the time they call us.

An honest answer on ozone

People ask about this constantly, so here is the straight version.

Ozone does neutralize odor compounds. It also is not safe to breathe. In the EPA’s assessment of ozone generators, no federal agency has approved these devices for use in occupied spaces, and at concentrations low enough to be safe, ozone does not do much. At concentrations that work, the air is hazardous.

There is no setting where it is both effective and safe to be around. That is why professional ozone treatment is done in a sealed, unoccupied building, with people and pets out, followed by a ventilation period before anyone goes back in.

So: the consumer ozone generator running in an occupied living room is a bad idea, and a company that leaves one with you and tells you to let it run is not doing you a favor. Used properly, as a final step in an empty building after the source is gone, it has a place.

Hydroxyl generators are the alternative and can generally run in occupied spaces. They work more slowly and need more time.

Thermal fogging puts a deodorizing agent into the air as a heated vapor so it follows the same paths the smoke took. It is useful, and it is a treatment rather than a removal. It does not replace taking the source out.

How we know it is finished

Odor work is hard to verify, which is exactly why some companies get away with treating instead of removing.

We do three things before calling it done. We warm the building, because heat is what brings odor back and testing a cold house tells you nothing. We open every enclosed space, including closets, cabinets, and the mechanical room. And we run the HVAC system, since that is the thing that will redistribute anything we missed.

If the building passes warm, closed up, with the system running, it will pass in October. If we skip that and check on a cool day with the windows open, we have tested nothing.

What you can do while you wait

• Leave windows open when the weather allows, since ventilation genuinely helps
• Do not run the furnace fan until the duct work has been checked
• Bag textiles you are not using so they do not keep absorbing
• Skip the odor foggers and candles, which add a scent on top rather than removing anything
• Leave closet and cabinet doors open so those spaces air out with the rest of the house

Common questions

How long until the smell is gone for good?

 If the source is removed properly, the odor should be gone when the work is finished, not fading over months. If someone tells you it will take a year to air out, that means source material is still in the building.

Do I have to replace my furniture?

 Not always. Most upholstered items can be treated through contents cleaning. Items with foam that absorbed heavy smoke are the harder case.

Can you treat odor without the demolition?

 Sometimes, on light exposures. On anything heavier, treating without removal is exactly the cycle that brings people back a second time.

Should I run my furnace fan to air the house out?

 Not until the duct work has been checked. Running the system pushes residue into rooms the smoke never reached.

Another company already treated it and the smell came back. Can you fix it?

 Usually. That situation almost always means the source was never removed, so we start with finding it rather than treating again.

Does painting seal in the smell?

 Ordinary paint does not. A proper sealing primer on bare framing or subfloor does, and it is a real step in the process. Painting over finished drywall that still holds odor just delays it.

Can I stay in the house during the work?

 Usually yes, apart from any ozone stage, which requires the building to be empty. We will tell you in advance if that is in the plan.

Call us

Odor work usually runs inside a wider fire damage restoration job rather than on its own. Kiser Construction handles smoke odor removal across Sherburne, Wright, Anoka, and Hennepin counties. We are IICRC certified and licensed in Minnesota under BC416441, and we do the cleanup and the reconstruction with one team.

Inspections are free and you get a written scope either way. If you have already had a company treat this once and the smell returned, say so when you call, because it tells us where to start looking.

Office: (763) 633-2010. Emergencies, any hour: (612) 518-8852.