Mold in Dover houses
Dover was proposed as Kent County's court town in 1683, and its streets and lots were laid out in 1717, so the city holds houses from nearly every period since. Old or new, they share the same weak points for mold: a basement or crawlspace that stays damp, an attic where warm air meets a cold roof deck, a bathroom without a fan that vents outside, and anywhere a leak has been quietly soaking a wall.
Mold is a symptom. It grows where water has stayed long enough, and in Dover the weather gives water plenty of chances to stay.
What the Dover weather station shows
Dover has its own NOAA engineering weather station at Dover Air Force Base, so these numbers are local:
- about 612 hours in an average year with the wet-bulb temperature above 73°F, and about 1,723 hours above 67°F;
- a 1% summer design temperature of 89°F with a mean coincident wet-bulb of 75°F;
- a 100-year rainfall rate of 3.0 inches per hour;
- about 51 freeze-thaw cycles in an average year.
Put plainly: summer air here carries a lot of water. When that air drifts into a cooler place, such as a basement, the back of a closet on an outside wall, or the space around a sweating duct, the water comes out of it and settles on the surfaces. A cloudburst at three inches an hour tests every gutter, downspout and window head, and dozens of freeze-thaw cycles a winter open small cracks in masonry, caulk and flashing that let the next rain in.
Start with the moisture
The most useful thing any mold company can do is tell you why the mold is there. Before you look at a cleanup price, ask:
- What is the water source: a leak, rain getting in, condensation or ground moisture?
- Has the source been stopped, and if not, who will stop it?
- How wet are the affected materials right now, and what tool measured that?
- What reading will count as dry when the work is done?
A plan that removes growth but never names the water is a plan to come back.
Basements, crawlspaces and attics
Many Dover homes have a basement or crawlspace, and these spaces are where humid summer air does the most harm. Cool foundation walls and floor framing pull moisture out of the air for months. Ask whether the company suggests drainage changes outside, a vapor barrier, sealing vents, a dehumidifier, or some mix of those, and ask why for your house in particular.
Attics are the winter version of the same problem. Warm, damp air rising from the house can condense on the underside of a cold roof deck. Stains or dark patches on the sheathing, frost on nail tips, or a musty attic smell all deserve a closer look.
Signs worth a call
- a musty smell that returns after cleaning;
- peeling or bubbling paint, or staining, on a ceiling or wall;
- dark spotting along baseboards, behind furniture on outside walls, or around supply vents;
- warped flooring or soft drywall;
- condensation on ducts or the air handler during summer.
What a careful job includes
- Containment. Plastic sheeting around the work area, kept under negative pressure with filtered exhaust, so spores don't spread to clean rooms.
- Removal. Porous materials with growth, such as drywall, insulation and carpet pad, cut out and bagged inside the containment.
- Cleaning. Framing and other hard surfaces cleaned and dried rather than replaced.
- Drying. Dehumidifiers and air movers, with readings logged until materials reach the target set in advance.
- The air system. If growth reached the air handler or ducts, they belong in the scope.
- The finish line. A clear statement of how the company will show the area is clean and dry before walls are closed.
Questions for the company itself
Ask how long the company has done mold work, and for references from jobs like yours. Ask what training its crew has for this work and who will be on site each day. Ask whether it will both assess and clean up, or whether it works from someone else's assessment, and get the written scope and price before work starts.
Comparing quotes
Line the quotes up on the same scope: square feet of each material removed, containment and air filtration, drying equipment and how dryness is measured, the air system if included, whether rebuilding is part of the price, and how the company will document the result.