How to Get Rid of Cockroaches in Your Bangkok Condo (And Keep Them Out)

Identify which one you have

• Large (3–5 cm), brown, flies or glides: American cockroach — coming from outside
• Small (1–2 cm), light brown with dark stripes: German cockroach — breeding inside
• Dark brown, medium-sized, flies well: Australian cockroach — often outdoor
• Your approach depends on which species is present

The American cockroach — blocking entry

1. Install mesh covers on all bathroom and kitchen drains when not in use
2. Seal gaps around pipes where they enter walls
3. Check the front door threshold — they walk in under poorly-sealed doors
4. Stop leaving wet towels and standing water overnight
5. Treat building drains (often the juristic office's job, but push for it)

The German cockroach — eliminating infestation

German cockroaches breed inside your kitchen. If you see one during the day, you already have dozens hidden in the walls and cabinets. This is where DIY usually fails.

1. Remove all food sources — store everything in sealed containers
2. Fix leaking pipes (they need water to survive)
3. Set gel bait in cracks near cabinets and appliances
4. Never spray surface insecticide on bait — it repels them from the bait
5. Wait 2–3 weeks for full kill cycle
6. If you still see roaches after 4 weeks, call a pro — you have a larger colony than gel bait can handle

When to stop DIY and call a professional

• You see roaches during the day (indicates heavy infestation)
• You see egg cases (small brown capsules in corners)
• You find dead roaches regularly (live ones nearby)
• You've done DIY for 4+ weeks with no reduction
• You have infants, elderly, or allergy-sensitive people in the home

What professional pest control does

Professional service combines gel bait, targeted residual spray, dust in wall voids, and entry-point sealing. A single professional visit usually eliminates a medium infestation within 2–3 weeks, with a follow-up visit included. Budget ฿1,500–3,000 per visit in Bangkok.