Detroit odors, gone for good.

Probably nothing. Sealing a surface is not the same as removing a source, and heat and humidity will pull it back through paint within a season. The source in a house like that is usually in subfloor, framing or plaster rather than in the finishes you replaced, so new flooring and fresh paint go over the top of it and buy you a few months. If you are mid-project, treating before the new flooring goes in saves doing the job twice, and it is genuinely cheaper at that stage because the source is exposed and reachable. If you are already finished, it is still fixable, it just costs what it would have cost plus the work of getting back to it.

Often, and the sensible point to bring us in is after the strip-out and before the finishes, when the source is exposed and cheapest to deal with. Contractors and flippers working the Detroit and Downriver stock deal with a specific version of this: houses that stood vacant and unheated for years, where the smell survives a full refit and shows up on the first showing. We can work to a construction schedule rather than a homeowner one, and we would rather be a half day in the middle of your programme than an emergency the week the photographs are booked.

That is the most common call we get, and it is not bad workmanship. Smoke residue is not on the surface, it is in it. Tar and nicotine condense out of warm air and work into plaster, drywall paper, timber, carpet backing and the inside of the ductwork, so a heavy clean and two coats buy you a few weeks and the first warm humid day brings it back through. Sealing does have a place, but only after the residue underneath has been dealt with and only on surfaces that genuinely cannot be treated. Doing it in the wrong order is the most expensive mistake we see, because the paint has to come off again before anyone can get at the problem.

It changes the scheduling and nothing else. We are about 1 hour 55 minutes out from Northeast Ohio, so a visit here gets booked to an agreed date rather than squeezed into the same day, and we would rather tell you that up front than promise same-day and miss it. The treatment, the equipment and the guarantee are identical to a job ten minutes from base. It does mean it is worth telling us everything on the phone, because a second trip out here to deal with something you forgot to mention costs us both more than it would locally.

Because by the time a room smells, the urine is almost never still in the carpet. It has gone through the backing, through the underlay and into the subfloor, and in an older house it will have found the gaps between the boards. Cleaning the carpet treats the layer holding the least of it. Urine also crystallizes as it dries, which is why the smell surges on a humid day and fades on a dry one, and why steam cleaning can briefly make it worse: you have just added moisture to the salts. We work out how far it went before deciding what to treat, and sometimes that means lifting a section of carpet to look. Knowing is cheaper than guessing.

We quote per job rather than publishing a rate, because the same smell in two houses is not the same job. What moves the price is how far the odor has travelled, not how bad it smells on the day. Cigarette smoke that has been in a house for years has gone into drywall, carpet backing and the inside of the ductwork, and that is a different piece of work to the same smell in a rental that was smoked in for one winter. Tell us the room count, the odor, and roughly how long it has been there, and we will call you back with a real number rather than a range that means nothing. The quote is free and there is no charge for a visit that turns into advice rather than work.

No, though it is common enough that people accept it. A musty smell is the by-product of organic material staying wet: untreated timber, cardboard boxes, old carpet, drywall that wicked up water once and never fully dried. It is worse in summer because warm humid air meets cool basement surfaces and condenses on them, which is the opposite of what most people expect. Before treating anything it is worth knowing whether the space is actively wet or only humid, because they need different answers. Active water is a drainage or sump problem and has to be fixed first. We will not tell you a treatment fixes a leak, and if water is still getting in we will say so before you spend money rather than after.

We come back and treat it again, and you do not pay twice. That is the whole of the guarantee, and it is deliberately short because a guarantee with conditions attached is not one. The reason we can offer it is that we treat the source instead of covering it, so there is usually nothing left to come back. Where a smell does return, it is almost always because something is still feeding it: water still getting in, a drain still open to the sewer, an animal still in the wall. In that situation we will tell you what needs fixing first rather than keep re-treating a symptom and billing you for it.