Why Cockroaches Show Up in New Flats Before You Even Move In

You collect the keys, walk into a freshly painted flat, and find a cockroach near the kitchen sink. It feels unfair — nobody has cooked a meal here yet. But cockroaches do not need your food to move in. They need water, warmth, shelter and a route, and a new apartment in Bangalore often offers all four.

This guide explains how cockroaches reach an empty flat, which areas to check during handover, and what to do before your furniture arrives.

The short answer

Cockroaches appear in new flats because the flat is connected to the rest of the building. They travel through shared plumbing stacks, drainage lines, electrical conduits and wall cavities from older or occupied units, and they arrive on construction material, cartons and tools. Gaps left around pipes and cabinets give them places to settle, and dried-out floor drains can open a path from the sewer line. A new flat is clean on the surface but rarely sealed.

Common ways cockroaches reach an empty flat

• Shared plumbing and risers: Pipe shafts run through every floor. Cockroaches climb them easily, and the cut-outs around pipes are often left unsealed.
• Construction debris: Cardboard, wood offcuts, packing material and sacks left by carpenters, electricians and painters make ready-made shelter.
• Workers' food waste: Interior teams often eat on site. Crumbs and leftovers in a corner are enough to feed a few roaches.
• Dry drain traps: In a vacant flat, the water seal in floor and basin traps can evaporate. Without that seal, drain pipes become an open path.
• Moisture from fresh work: Plaster, tiling and waterproofing keep walls damp for weeks, which suits cockroaches.
• Delivered goods: Cartons from appliances, furniture and groceries can carry roaches and egg cases inside.

Which species to expect

Two types are most common in Bangalore apartments. German cockroaches are small, light brown and stay close to kitchens and bathrooms. They breed quickly and usually arrive on cartons or through shared walls. American cockroaches are larger and reddish-brown, and they tend to come up from drains and sewer lines. Knowing which one you see tells you where to look first.

What to check at handover

1. Look under the kitchen sink and around the water inlet and outlet pipes for open gaps.
2. Check the gap between the modular kitchen cabinets and the wall.
3. Inspect bathroom floor drains and fill each one with water.
4. Open every cabinet and look at the back panel and hinges for droppings, which look like pepper grains or small dark smears.
5. Check the electrical switchboards and the gap around the meter panel.
6. Look at the balcony drain and utility area.

What to do before you move in

Seal visible gaps around pipes with a suitable sealant or cement, and ask your contractor to close the openings behind the cabinets. Run water in every drain for a minute so the traps refill, and repeat weekly if the flat will stay empty. Remove all cartons and packing material from the flat instead of storing them in a corner. If roaches are already present, get the flat treated before you unpack. A treatment on an empty home is easier and more thorough because every cabinet and gap can be reached, and nothing needs to be covered or moved.

When to call a professional

Call a professional if you see roaches during the day, find droppings or egg cases, or notice a musty smell in the kitchen. Daytime activity usually means the population is already crowded. A professional treatment with gel bait and crack-and-crevice application targets the hiding places that sprays miss, and it is better done before the flat is furnished.

Frequently asked questions

Is it normal to find cockroaches in a brand-new apartment?

It is common. New buildings share plumbing and wall cavities with other flats, and construction work brings in material that cockroaches can ride on. Finding one does not mean the flat is dirty.

Should I treat the flat before or after furnishing it?

Before is easier. With empty cabinets and open floors, a technician can reach every gap, and you avoid moving furniture and covering belongings afterwards.

Can cockroaches live in a flat with no food?

For a while, yes. They can survive on very little, including glue, paper and traces of grease, and they need water more than food. Damp plaster and drain moisture can sustain them.

Will sealing gaps alone solve it?

Sealing helps prevent new entry, but it does not remove roaches already inside. Use it together with a proper treatment.

This guide is part of IPest's complete resource on cockroach control. For identification help, prevention and treatment options, see our full cockroach control guide for Bangalore.