Mold Inspection on Spokane's South Hill

We test for mold across the South Hill. We do not remediate and we take no referral fees from the companies that do, which matters more here than it does in most neighborhoods, because the quotes on these houses are large.

A standard inspection is $425 including the visit, moisture and visual survey, one indoor air sample, a same-day outdoor control and accredited lab analysis with lab fees in the price. The South Hill is about twenty minutes from our base in Spokane Valley.

The housing stock is the whole story

Much of the South Hill went up between roughly 1900 and 1940, and the good ones were built well. But they were built to a different set of assumptions about what a basement is for, and almost every problem we find up here traces back to one of those assumptions being overturned later.

Basements that were never living space. Stone or early poured foundations, often with no vapor barrier under the floor and sometimes no real floor at all. That was fine when the basement held a coal bin and a furnace and nothing you cared about. It is a different matter once it holds a finished family room, carpet and drywall. Finishing an original basement without addressing what the floor and walls are doing is the single most common way a South Hill house develops a mold problem.

Insulation retrofitted into walls that were designed to breathe. Blown-in cellulose or foam into a wall cavity that has no vapor control on the warm side moves the condensation point into the middle of the assembly. The wall then gets wet in winter where nobody can see it. See mold in a closet on an exterior wall.

A century of additions. Sunrooms, dormers, converted porches, a bathroom added in 1972. Each junction between old construction and new is a place where flashing may or may not have been done properly, and where two roof planes meet is where the water gets in.

The hill is literally a hill

The South Hill rises several hundred feet above the river, and much of it is basalt with a shallow soil cover. Water moving downslope encounters foundations sideways rather than from below.

The result is a pattern you can almost predict from the street. On a sloped lot, the uphill wall of the basement is the wet one, and it is wet after weather rather than continuously. The repair is on the uphill side and it is about intercepting water before it reaches the wall, not about pumping it out afterward. Homeowners get sold interior perimeter drains for this fairly often. Sometimes that is the right call. Frequently the cheaper exterior fix was never priced. See a damp basement after rain.

Where the money is at risk

South Hill houses are expensive, which changes what a mold finding costs you in two directions.

In a sale. A buyer's inspector notes something in the basement, the deal stalls, and now everyone is negotiating over an unknown. An independent air and surface test turns an unknown into a number, and a number is negotiable in a way that a worry is not. Sellers are usually better off knowing first. See pre-listing inspections and selling a house with mold.

In a remodel. These houses get opened up, and what is behind the plaster is frequently a surprise. Finding growth mid-project with a crew standing there produces fast decisions and expensive ones. Testing before the demolition is scoped, rather than after, is the cheaper order of operations.

In both cases the useful thing about hiring someone who only tests is that our number does not move with the size of the job. We are not quoting the removal, so there is no version of this where we benefit from the finding being worse.

The bedrock is closer than you think. Across much of the hill you have a shallow cap of soil sitting on basalt, and in places the rock is only a few feet down. Water that falls on the upper hill does not percolate straight into the ground the way it does out on the prairie. It moves down through that thin soil until it reaches rock, then it runs sideways along the top of the basalt until something interrupts it. On a hillside full of houses, the thing that interrupts it is somebody's foundation. This is why two neighbors on the same block can have completely different basements, and why the house that floods is often uphill of the one that stays dry.

Daylight basements cut into the slope. The standard South Hill move is to cut into the grade so the downhill side opens to the yard and the uphill side is buried to the ceiling. That buried wall is the one taking the lateral water described above, and it is almost always the wall somebody finished. Bedrooms, offices and rec rooms get built against it, insulation and drywall go on with no gap and no drying path, and the assembly stays wet from behind for years without a drop ever appearing on the floor. When we find growth in a South Hill basement, better than half the time it is on the uphill wall behind finished framing.

The old stone foundations. On the lower hill, through Cannon Hill and Rockwood and the streets off Grand, you get rubble basalt foundations laid in lime mortar a hundred or more years ago. No damp proofing was ever applied because it did not exist, and no footing drain was installed because nobody installed them. Those walls have been wet and dry on a seasonal cycle since before the Depression, which is fine as long as they can breathe. The problem arrives when an owner in 1978 or 2014 frames a wall an inch off the stone and covers it. We can tell you whether the wall is doing anything new or whether it is just doing what it has always done, which is a distinction that saves people a great deal of money.

Hydronic heat and no ductwork. A lot of these houses still run boilers and radiators, and a house with no ducts has no path for whole house air conditioning, which also means no path for whole house dehumidification. Summer comes, the windows go up, smoke season arrives and the windows go down, and the humidity that would normally get pulled out by a central system just sits. Window units handle a room. They do nothing for the basement two floors below, which is where the cool surfaces are.

The tree canopy. The mature trees are the reason people love these streets and they are also a maintenance load nobody budgets for. Gutters fill with needles and leaf litter and overflow against the foundation in exactly the season you would least want that. Deep shade on north and east walls means siding and masonry that never fully dry, moss on the roof, and a wall assembly that stays a few degrees cooler than everything around it. Cool and damp is the whole recipe.

Moran Prairie, Glenrose and the newer South Hill

Push south past 44th and the housing changes completely, and so do the problems. Out through Moran Prairie and Glenrose you are into newer construction on larger lots, tighter building envelopes, and mechanical ventilation that was installed to code and then never balanced or maintained. The shallow soil over basalt is still there, but now it is under a slab or a shallow crawlspace rather than a full basement, and it is combined with lawn irrigation running on a timer across a big lot from May to September.

The failure looks different. Instead of a hundred year old wall weeping, you get a tight house with too little air exchange, a bathroom fan that moves less air than its label claims, and moisture that has nowhere to go. Newer does not mean drier. It frequently means the opposite, because an older house leaked enough to dry itself out by accident and a new one does not.

Testing before you list

The South Hill turns over a lot of expensive houses, and that changes the math on when to test. In a normal transaction the sequence is that a buyer's inspector writes something careful and non committal, the buyer gets nervous, and now you are negotiating under a contingency clock with no actual information on the table. Everybody is arguing about a photograph.

If you test before you list, you control the timing and you control what the report says, in the sense that you find out first rather than last. A clean result removes the leverage entirely. A result that is not clean is something you can address on your own schedule, with your own contractor, at your own price, rather than as a credit negotiated in the last ten days of escrow at whatever number makes the buyer go away. The test costs the same either way. Only the position changes.

What it usually turns out to be

On the South Hill the causes repeat. Roof water dropped at the foundation on the uphill side. Gutters packed with tree litter. A finished basement wall built tight against stone or block with no capillary break. Grade that has crept back toward the house over decades of added landscaping and retaining walls. Bath fans venting into attics or into soffits that push the air straight back in. A hydronic system with a slow leak at a radiator valve, which is one of the few genuinely hidden sources we find and one of the easiest to miss.

What it is almost never is the thing the homeowner has imagined between calling us and our arrival. Most of what we find is old, cheap to correct, and has been running quietly for a decade. That is the honest answer, and it is why we would rather tell you on the phone whether a test will answer your question than take money for one that will not.

What the visit looks like

Moisture meters throughout, thermal imaging where a wall or ceiling is suspected of being wet behind the finish, one indoor air sample placed at the complaint, an outdoor control the same day, and surface sampling of anything visible worth identifying. Written report with the raw lab data attached, about two business days. Then a call, because a spore count on its own is not an answer.

On an older house we will also tell you plainly when what you have is a building performance problem rather than a mold problem. Plenty of South Hill basements need a dehumidifier and a downspout rather than a contractor.

Booking

Call (509) 355-0038. If you are working to an inspection contingency or a closing date, tell us and we will schedule to it.

Frequently asked questions

Is a musty smell in an old basement just what old basements smell like? Partly. An original unsealed basement will always smell more like earth than a finished one does. But musty is specifically the smell of microbial growth, not of age, and the distinction matters once the space is finished or once the air from it is reaching the rest of the house. Testing separates the two.

We are thinking about finishing the basement. Should we test first? Test and meter first, yes. The question you actually need answered before you frame anything is what the floor and the walls are doing with moisture, because finishing over an active moisture source is how a nice basement becomes a gut job in four years.

A buyer's inspector flagged mold. Do I need remediation? Not necessarily, and you cannot tell from a visual note. Some of what gets flagged on an old basement wall is efflorescence, which is mineral salt and not biological at all. Some is surface growth that cleans off. Some is the visible edge of something bigger. A test tells you which, and it costs a fraction of the quote you would otherwise be negotiating against.

Do you work with real estate agents? Regularly, on the same terms as anyone else. We do not soften findings for a transaction and we do not take referral fees in either direction. Agents who send us work do it because an independent number closes arguments faster than an opinion does.

Our house is 1920s and has knob and tube era walls. Does insulation cause mold? Insulation does not cause mold, but insulating an old wall without thinking about vapor can. Filling a cavity that was designed to dry by air movement moves the cold surface into the middle of the wall, and if warm indoor air can reach it, it condenses there. That is a real and fairly common failure in houses of this age on the hill.

How long does the inspection take? Usually ninety minutes to two hours for a typical South Hill house, longer if it is large or has had several additions. Results follow in about two business days.