Rodents in the attic and other home inspection issues

Rodents in the attic on a home inspection: what to do

If the report shows rodents in the attic, book a licensed pest control or wildlife removal company to look before your inspection deadline, then ask the seller to cover its written price, as a repair or a credit. Under the International Association of Certified Home Inspectors (InterNACHI) standards, your inspector isn't required to check for signs of rodents, so the report is a lead, not a full count. Ask the pest company what they found and where, and which entry points they will seal.

Two other attic lines can show up with it: a bathroom fan that vents into the attic, and thin insulation.

Key takeaways

• Fix the bath fan duct before anyone adds insulation. ENERGY STAR lists attic-venting fans as a problem to correct first.
• Insulation disturbed by pests may need to come out. Removal runs $1 to $3 a square foot, on top of the new insulation.
• For an uninsulated attic, ENERGY STAR's target runs from R30 in the warmest zone to R60 in cold ones.

Is rat poop in the attic dangerous?

It can be. The Centers for Disease Control and Prevention (CDC) says rodent droppings can carry hantavirus, which "can cause serious illness that affects your lungs and kidneys." The risk comes from disturbing it: "When fresh urine, droppings, or nesting materials of an infected rodent are stirred up, the virus can get into the air."

So don't touch it on your walkthrough. CDC's cleanup guidance says: "Don't vacuum or sweep rodent urine, droppings, or nesting materials." Leave the cleanup to the company you hire.

A Boise pest company, ProGuard, lists bits of chewed wire jacketing among the signs. If the pest company finds chewed wiring, get a licensed electrician into the attic before your deadline, not after closing.

How much does rodent removal in the attic cost?

Prices swing with scope. A short job traps and seals. A long infestation adds new insulation, cleaning and repairs. Two local companies publish their numbers:

Match the row to what your inspector photographed. The longer rodents have lived there, the more the job includes, as Homeland's second row shows. The CDC's rodent plan has three parts: trap, seal up holes, and clean up safely. Check that each bid covers all three.

Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote.

Should a bathroom fan vent into the attic?

No. InterNACHI is direct: "Vents must terminate at the home exterior." When a duct ends in the attic (or loft), warm, moist air condenses on cold framing and insulation. InterNACHI calls "the potential accumulation of mold in attics or crawlspaces" perhaps the most serious result. Wet insulation also insulates less well.

If mold turns up where the duct ends, read mold in the attic on an inspection report. For how mold sits next to radon and asbestos, see the mold, radon and asbestos findings hub.

The fix is a duct run to a roof or wall cap. Fixr prices installing a fan from scratch, which includes routing a duct outside, at $250 to $900. Your job may need only the duct, so get a written bid from a heating and cooling contractor or an electrician.

Is adding insulation to the attic worth it?

Yes, up to the level ENERGY STAR calls cost-effective for your climate. ENERGY STAR calls the attic one of the biggest chances to save energy in a home. With air sealing, more insulation can also help limit ice dams in winter.

ENERGY STAR's recommended levels depend on climate zone. For an uninsulated attic, it recommends R30 in zone 1, R49 in zones 2 and 3, and R60 in zones 4 to 8. With 3 to 4 inches already down, the targets drop to R25 through R49.

Order matters. The EPA recommends air sealing the attic before adding insulation, so that is its own line. ENERGY STAR also says to have a professional correct bath fans that vent into the attic before you insulate.

You don't need to pull insulation that is in good shape. Fixr suggests replacing it if it is old, degraded or disturbed by pests. If the old insulation is vermiculite (a flaky, gray, pea-size mineral), have it tested before anyone disturbs it. ENERGY STAR warns it "may contain asbestos."

What should you ask the seller for?

Ask for each line by scope, trade and a written bid. Get the pest, duct and insulation visits booked early; how to get repair estimates during the inspection period covers scheduling.

A worked example, for an attic with rodents, soiled insulation and a bath fan venting into it, using the ranges above:

• Rodent removal and exclusion, Homeland's 1-to-2-month line (San Antonio): $800 to $2,000
• Remove and replace insulation, 1,000 sq. ft.: $3,000 to $6,250
• Duct to the outside, Fixr's fan-with-duct range: $250 to $900

Low ends: $800 + $3,000 + $250 = $4,050. High ends: $2,000 + $6,250 + $900 = $9,150. A 6-month-plus infestation is priced as one job at Homeland's $5,200 to $12,000+, which already includes insulation replacement and duct repair, so do not add separate insulation and duct lines on top of it. Air sealing, and any electrical repair for chewed wiring, add to that; get those figures from the insulation contractor and the electrician. Swap in your own bids as they arrive. If the seller hires the companies instead, ask for the invoices showing what was sealed, cleaned and replaced.

What to ask for after a home inspection covers which lines to include. The buyer repair request letter template gives you the wording.

What if the seller says no?

You have three moves:

• Ask for a credit instead of the work, sized to the bids, so you hire the companies after closing.
• Split the list. Keep the rodent work, the soiled insulation and the duct, and drop any extra top-up.
• Walk away if the pest company finds damage no one can price before your deadline. When to walk away after a home inspection walks through that call.

Your contract sets the deadline and how you can cancel, so confirm both with your agent or attorney.

Is it against code to vent a bathroom fan into the attic?

It depends on the residential code your town has adopted. Your local building department, or a licensed contractor, can answer for your address. InterNACHI's guidance is plain either way: ducts "should never terminate within the building envelope."

How much does it cost to insulate a 2,000 square foot attic?

Fixr says most people pay $2 to $3.25 a square foot. For 2,000 square feet, that's $4,000 to $6,500 ($2 × 2,000 and $3.25 × 2,000). Removal of old insulation is extra.

How do I know what my whole list is worth?

The attic is one line of a long report, and the rest need a number before you send your request.

If you want every line priced, upload your inspection report to Kept and spend your remaining days getting the pest and insulation bids.

Sources

• CDC, Hantavirus Prevention
• CDC, How to Clean Up After Rodents
• CDC, Controlling Wild Rodent Infestations
• InterNACHI, Home Inspection Standards of Practice
• InterNACHI, Bathroom Ventilation Ducts and Fans
• ENERGY STAR, Attic Insulation Project
• ENERGY STAR, Recommended Home Insulation R-Values
• Fixr, Attic Insulation Cost
• Fixr, Cost to Install a Bathroom Exhaust Fan
• ProGuard Pest Control, Rodent in Attic Removal Cost
• Homeland Wildlife, The Hidden Cost of Rodents in Your Attic
• Wildlife Company, Permanent Mouse Exclusion and Removal Pricing