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Derry, New Hampshire mold guide

Mold Guide for Derry, New Hampshire

Local mold risk drivers, seasonal priorities, and next steps for homeowners and renters in Derry.

State law data last updated: 2026-02-11

Overview

At 40.4 inches of yearly rain and an average of 50.1 F, Derry experiences a mix of wet spells experiences and dry breaks.

Statewide weather patterns in New Hampshire compound local risks, since humidity swings and storm seasons can push indoor moisture above safe levels.

Derry has cold winters and warm, humid summers, so moisture risk shifts between snowmelt and summer humidity.

Derry Code Enforcement handles property maintenance complaints and inspections.

This guide highlights local moisture drivers, seasonal risk, and prevention steps. For legal rights and landlord obligations, review the New Hampshire mold laws guide.

Sources: [New Hampshire | Britannica] | [Derry Code Enforcement] | [NOAA Climate Normals - MANCHESTER AP, NH US]

Action Checklist

Get free access to the full guide

8-step checklist for immediate action

Derry Home Inspection Checklist

Common construction types in Derry affect where moisture problems develop. Here is how local building patterns shape what to inspect.

In Derry, code Enforcement handles property maintenance complaints and inspections.

Documenting moisture issues helps support inspection follow up.

Sources: [Derry Code Enforcement]

  • Derry gets roughly 40.4 inches of precipitation per year. Schedule gutter, roof, and drainage inspections seasonally.
  • Roof flashing, gutters, and downspout extensions.
  • Attic insulation and ventilation near eaves.
  • Basement walls, sump pits, and floor drains.
  • Window frames and sills with condensation.
  • Bathroom exhaust fans and vent ducts.
  • Water heater pans and HVAC condensate lines.
  • Laundry hoses and shutoff valves.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - MANCHESTER AP, NH US]

Warning Signs of Mold in Derry

Watch for these signs that moisture is lingering in Derry homes and rentals:

  • Persistent window condensation in Derry (annual average 50.1 F) is a common early indicator that indoor humidity is too high.
  • Condensation that returns on windows each morning.
  • Musty odors in basements or closets.
  • Peeling paint near baseboards.
  • Dark spotting near ceiling corners.
  • Soft drywall around tubs or showers.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - MANCHESTER AP, NH US]

Mold Risk Factors in Derry

These are the most common moisture drivers for homes and rentals in Derry:

  • Climate records show Derry getting 40.4 inches of annual precipitation, so storm events and small leaks both matter.
  • Snowmelt and ice dams can leak into attic edges.
  • Freeze thaw cycles stress roof flashing and exterior joints.
  • Humid summers slow drying after leaks.
  • Condensation builds on windows during cold snaps.
  • Basements can stay damp after heavy rain.

Sources: [New Hampshire | Britannica] | [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - MANCHESTER AP, NH US]

Derry Seasonal Risk Calendar

Winter

Heating systems work most of the year at 50.1 F average. Ventilate consistently to prevent moisture buildup on cold surfaces.

Spring

Thaw and rain keep basements damp. Monitor sump pumps.

Summer

Cool summers still bring rain. Inspect roof edges after storms.

Fall

Storms return. Recheck roof edges and window seals.

Sources: [New Hampshire | Britannica] | [NOAA Climate Normals - MANCHESTER AP, NH US]

Derry Moisture Playbook

Use this short playbook to stay ahead of common moisture problems in Derry.

After a Leak

Stop the leak, remove wet materials within 24 to 48 hours, and dry the area with airflow.

Monthly Maintenance

Inspect under sinks, clear condensate lines, and log basement humidity.

Seasonal Tune Up

Before storm season, clear gutters and inspect flashing; about 40.4 inches of annual precipitation means small leaks can add up.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - MANCHESTER AP, NH US]

Mold Prevention in Derry

Use these priorities to keep indoor humidity low and avoid recurring growth:

  • At 40.4 inches of annual rainfall, maintaining clear gutters and extending downspouts well away from foundations is essential.
  • Maintain indoor humidity between 30 and 50 percent.
  • Dry wet materials within 24 to 48 hours.
  • Vent bathrooms and kitchens outdoors.
  • Clear gutters and direct downspouts away from foundations.
  • Inspect roof flashing and window seals before storm seasons.
  • Service HVAC condensate drains annually.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - MANCHESTER AP, NH US]

State Laws and Rights

New Hampshire mold law snapshot

New Hampshire has mold-specific rules in addition to general habitability standards.

New Hampshire recognizes an implied warranty of habitability for all residential rentals. This warranty means that landlords must provide and maintain safe and habitable rental property, whether or not the lease agreement specifically says so and even if the lease tries to waive the obligation. To constitute a breach, the defect must be of a nature and kind which renders the premises unsafe or unsanitary, and thus unfit for living therein. RSA 48-A:14 establishes specific minimum standards including requirements for pest-free conditions, functional plumbing, electrical safety, structural integrity, adequate water supply, and heating facilities capable of maintaining at least 65 degrees Fahrenheit in habitable rooms.

Use the full New Hampshire guide for tenant rights, landlord responsibilities, and remedies.

Frequently Asked Questions

What are the first signs of mold in a Derry home?
Musty odors, condensation on windows, peeling paint, and dark spots near vents or ceilings are common early signs. If symptoms persist after cleaning, schedule an inspection.
When should I hire a mold professional in Derry?
If the affected area is larger than about 10 square feet, if growth returns after cleaning, or if anyone has health symptoms, hire a pro. Use the DIY vs pro guide to decide.
Do ice dams cause mold in Derry homes?
Ice dams trap snowmelt on roofs, which can seep into attics and walls. Proper attic ventilation and insulation help prevent them. See attic mold prevention.
How does winter condensation lead to mold in Derry?
Warm indoor air meeting cold surfaces creates condensation on windows and in attics. Run exhaust fans and check for wet insulation. Review prevention strategies.
Does Derry humidity make mold more likely?
High outdoor humidity slows drying after leaks, which raises risk. Active ventilation and dehumidification are key. Review prevention priorities for humid climates.
What should I do about mold after a Derry storm?
Stop the water source, remove wet materials within 48 hours, and run fans and dehumidifiers. Photograph damage for insurance. See the storm recovery guide.