Drill-and-Fill Termite Treatment: How Post-Construction Treatment Works

When termites are found in a building that is already complete, the soil under and around it can no longer be treated from above. The standard answer is drill-and-fill, also called post-construction treatment: small holes are drilled at intervals and termiticide is injected to create a chemical barrier.

This guide explains how it works and what to expect.

The short answer

In drill-and-fill treatment, the technician drills small holes along the floor edge, walls and any cracks and junctions, then injects a liquid termiticide through the holes to treat the soil and masonry beneath and around, forming a barrier that termites cannot safely cross. The holes are then sealed. Treatment may also include the perimeter soil outside the building and direct treatment of affected wood. It is generally done in a day or so for an average home, with some noise, dust and smell.

Where holes are drilled

• Along the inside edge of ground-floor walls, at regular intervals.
• Around columns, pipes and service entries.
• Along cracks and expansion joints.
• Outside along the plinth, where soil is accessible, through trenching or drilling of paved areas.
• At the base of door and window frames and wooden fittings in contact with the floor.

The steps

1. Inspection: The technician identifies activity and likely entry points.
2. Marking: Drill points are marked along walls and floors.
3. Drilling: Small holes are drilled to the required depth.
4. Injection: Termiticide is injected under pressure into the holes.
5. Perimeter treatment: The soil outside the building is treated where possible.
6. Wood treatment: Affected or at-risk wood is treated.
7. Sealing: Holes are filled with cement or a suitable filler.
8. Documentation: A treatment record and warranty are issued.

How it protects

The treated soil and masonry act as a barrier, either repelling or killing termites that try to cross it, depending on the product. It cuts their route between the soil colony and the building.

What to expect at home

• Noise and dust from drilling.
• Furniture may need to be moved from walls.
• Some smell for a short while, depending on the product.
• Tiles or floors may have small drilled and filled spots.
• You may need to stay out for a few hours, as advised.

Limits

Drill-and-fill depends on good coverage. Gaps in the barrier, disturbed soil and later construction can reduce protection. It does not repair damage, and it works best with moisture control and regular inspection.

When to call a professional

Choose a licensed provider who explains the chemical, spacing, depth and warranty, and who carries out the work carefully. Ask for a written plan.

Frequently asked questions

Will it damage my flooring?

Small holes are drilled and sealed. Some visible marks may remain on certain floors.

Is it safe for children and pets?

Follow the provider's re-entry and ventilation advice, and ask for product details.

How long does the barrier last?

That depends on the product and conditions. Refer to the warranty.

Is it only for ground floors?

Mainly ground level and risk areas, but other floors may be treated if there is activity.

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