How to Spot Pest Damage During Your House Inspection

The excitement of finding your perfect home can quickly turn to heartbreak when you find thousands of dollars of hidden pest damage. Don’t let your dream purchase become a financial nightmare – an easily avoidable outcome with a proper house inspection and pest damage detection carried out before you confirm your property investment.

Our comprehensive guide explains everything you need to know about detecting pest damage during property inspections. Keep reading to make informed decisions about your property purchase before signing on the dotted line and to know when you will benefit from a professional pest inspecton and how to get free advice.

Why Pest Damage Detection Is Crucial Before Purchase

In New Zealand, structural pest damage repairs can cost between $3,000 and $20,000, with severe cases requiring extensive foundation work that can reach higher amounts for large or heritage properties – exactly the type of charming character homes that are common in the Wellington region.

These unexpected costs can push your monthly budget beyond breaking point. Properties with a history of major pest problems can experience significant reductions in market value, making future sales more challenging in our dynamic property market.

And perhaps most importantly, insurance companies frequently exclude pest damage from standard residential policies, leaving homeowners to shoulder the entire financial burden with no safety net.

Investing in thorough pest damage inspection from a local specialist before purchase will not only protect your bank balance, it safeguards your family’s safety, and ensures your property remains a sound long-term investment in New Zealand’s competitive housing market.

Common Types of Pest Damage

Borer

Borer wood damage issues are incredibly common in New Zealand homes, particularly in properties built before the 1960s, when untreated timber was standard. Borer beetles are detectable if you know what to look for, but the damage can be just as devastating.

The most obvious sign of borer damage is the presence of small, round exit holes in timber surfaces, ranging from 2mm for Common House Borer to 7mm for Two-Toothed Longhorn Borer. Fresh holes will have clean, sharp edges and may have fine white-to-cream-coloured wood dust (called frass) around them, indicating active infestation. If you want to work out whether what you have found is current or historic, our guide on how to tell if borer is active covers the difference in detail.

Run your hands along wooden surfaces, particularly around window frames, skirting boards, and exposed beams. Active borer damage often causes timber to feel soft or spongy, and you might even hear a faint ticking sound from within the wood as larvae feed.

It’s also important to note that many people confuse termites with borer as they both destroy timber in homes. New Zealand does have a few native termite species, but they aren’t structural pests of houses in the way Australian termites are. So if you’re worried that you’re buying a house with termites due to wood damage, what you are almost certainly looking at is borer.

Rodents

Rats and mice might seem less threatening than wood-destroying insects, but they cause significant damage through gnawing, nesting, and contamination. During your house inspection, look for dark, rice-sized droppings in cupboards, walls, and roof spaces. Fresh droppings are dark and moist, while older ones become grey and crumbly.

Check for gnaw marks on wooden structures, particularly around food storage areas and along pipe runs. Rodents’ teeth grow continuously, so they chew on anything to keep them worn down – including electrical cables – creating serious fire hazards. Look for shredded insulation, paper, or fabric indicating nesting sites. Strong, musty pet shop-like smells can also be a sign of rodents. Read more about our rodent control services.

Other Pests

Other common pests leave their own signatures: wasp nests in wall cavities can cause staining and structural damage, while carpet beetles create irregular holes in natural fibres.

Cockroach infestations often leave dark staining and an oily odour in kitchen and bathroom areas, particularly around hot water cylinders and behind appliances.

Your Pest Damage and House Inspection Checklist

1. Exterior Inspection Points

Begin at ground level by examining the foundation walls and concrete pads. Look for hairline cracks in concrete or gaps where pests could enter; even tiny openings can provide access for ants or other destructive insects. Check where wooden structures meet the ground, particularly deck posts, steps, and pergola supports.

Walk around the entire perimeter, paying special attention to areas with poor drainage or where guttering overflows. Moisture accumulation creates ideal conditions for pest breeding, so note any areas where water pools against the house or garden sprinklers regularly hit exterior walls.

Examine weatherboards, cladding, and external joinery carefully. Look for small holes around window and door frames where borer beetles often attack first.

Don’t forget to check the roof line and eaves. Missing or damaged roof tiles create entry points for birds and rodents, while blocked or overflowing gutters can cause moisture problems that attract other pests.

2. Interior Red Flags

Start with the main living areas, examining skirting boards, window frames, and any exposed timber features.

The kitchen and bathrooms deserve special scrutiny during your house inspection and pest damage assessment. Check inside cupboards for rodent droppings, particularly in corners and behind stored items. Look for gnaw marks on wooden shelving or evidence of insects around food storage areas. Under-sink areas are notorious for pest activity due to plumbing moisture, so examine all timber thoroughly and check for any soft spots or unusual odours.

In bedrooms, focus on built-in wardrobes and around windows where condensation might create moisture problems. Pull back carpet edges where possible to check skirting boards for borer holes – these areas are often overlooked during casual viewings but can reveal extensive hidden damage.

Pay attention to internal doors and frames, particularly older wooden doors, prime targets for borer beetles. Check both sides of door frames and run your hands along surfaces to feel for irregularities that might indicate pest activity beneath paint or stain.

Living areas with fireplaces require careful inspection too. Check wooden mantels, surrounds, and any exposed beams for flight holes or soft spots. The combination of warmth and sometimes poor ventilation around fireplaces can attract various pests.

3. Attic and Roof Space Warning Signs

If you can safely access roof spaces and subfloor areas, these zones often reveal the most telling evidence of pest problems. Pests establish major colonies in these hidden areas and cause extensive damage away from human interference.

In roof spaces, look for disturbed insulation that might indicate rodent activity or nesting. Check exposed timber framing for borer wood damage, particularly in older homes where untreated timber was common. Fresh wood dust or frass around holes indicates active infestations that require immediate attention.

Examine any stored items in roof spaces for pest damage. Old furniture, boxes, or timber offcuts often show clear signs of borer activity. This can give you insight into the property’s pest history and potential ongoing problems.

Use a torch to examine all accessible timber thoroughly. In subfloor areas, probe wooden structures gently with a screwdriver – compromised wood will give way easily or sound hollow when tapped. Look for any areas where timber appears darker than the surrounding wood, which might indicate moisture damage that attracts pests.

Remember that poor ventilation in subfloor areas creates perfect conditions for pest breeding, so note any areas with inadequate airflow or signs of ongoing moisture problems.

When to Call in the Experts

While this comprehensive checklist empowers you to identify obvious pest damage signs during your property viewing, understanding what you’ve found and how to address it is where professional expertise becomes invaluable.

If you discover any evidence of pest activity during your pest damage house inspection, don’t panic. This is valuable information that helps you understand the maintenance requirements and budget needed to maintain a pest-free home you can enjoy. Builders reports often identify pest issues including borer, and these findings should inform your decision-making process. If borer has been flagged in a report on a home you are looking at, our free new-home pest check will tell you what it actually means for the property before you commit.

At Combat Pest Control, we help new homeowners navigate their options. Whether you need guidance on borer treatment approaches or want to develop a long-term pest management plan for your new property, our expertise and knowledge are here to support you. We can explain the treatment options available and how to approach protecting your home from pests, giving you the confidence to plan for ongoing maintenance.

You get a LIM and a builder’s report before you buy. A pest check is the same kind of due diligence, and ours is free. Book a free new-home pest check and know exactly what you are buying.