Written By Robert Mac
Ventilation is essential in any home — especially in rooms like the kitchen, bathroom, and utility area. Whether you’re installing a new extractor fan, fitting a dryer vent, or running a PVC duct for air extraction, knowing how to drill a vent hole in your wall is a vital part of the process.
Whether you’re installing a bathroom extractor fan, a kitchen cooker hood, or a tumble dryer outlet, drilling a vent hole through a wall is a common DIY project.
This guide will walk you through how to drill through brick, block, or cavity walls safely and cleanly — ideal for anyone asking “how do I install a wall vent for ventilation or air extraction?”
Core drill with diamond core bit (typically 100–125mm / 4″–5″)
SDS drill or rotary hammer for the pilot hole
Long masonry drill bit (10–12mm x 400–600mm)
Safety gear: goggles, gloves, dust mask, ear protection
Dust sheets or plastic sheeting
Spirit level, measuring tape, marker or chalk
Ventilation kit (includes duct sleeve, internal flange, external grille)
Wall scanner or pipe/wire detector (to locate studs, electrical cables, or plumbing before drilling)
⚙️ Tip from the trade: You don’t need to spend hundreds on tools for one or two holes.
All the heavy-duty drills and core bits you need are available to hire from A-Z Hire in Dublin — perfect if you’re not doing this type of work regularly.
Hiring a professional-grade core drill is much more cost-effective than buying, and you’ll get expert advice on using it safely and correctly.
Start by choosing the right location for your vent outlet:
Avoid wall studs, electrical cables, and plumbing.
Plan for straight ducting if possible — the fewer bends, the better the airflow.
Think about the internal side (for fan or vent unit) and external side (for grille).
If you’re fitting a duct for an extraction system or air ventilation unit, make sure the vent outlet complies with ventilation regulations, especially in bathrooms and kitchens.
Use the duct sleeve or internal vent as a template to mark the circle.
Mark the center point clearly.
Use a spirit level to ensure everything is square.
For external vent installation, make sure the vent outlet is positioned to avoid blowing warm, damp air toward windows or into covered areas, which could cause condensation or mold.
Use a long masonry bit (10–12mm) with an SDS drill to make a pilot hole through the wall.
Drill slowly and evenly, keeping the bit level and straight.
Drill from the inside out, stopping as soon as the bit breaks through.
This pilot hole will guide your core drill and help align both sides of the wall if you need to drill from inside and out.
Attach the diamond core bit to your hired core drill.
Start from the inside, using your pilot hole as a guide.
Use a rotary-only mode (no hammer action) and apply steady pressure.
Let the tool do the work — don’t force it.
Diamond core drills are ideal for cutting through masonry walls, especially when you’re creating a hole for a 100mm or 125mm ventilation duct.
If you’re wondering how to drill through an exterior wall for a vent, this is the safest and cleanest method.
For thick or cavity walls, you may want to drill halfway from each side to avoid damaging the outer brick face.
Clear out debris with a brush or vacuum.
Insert the PVC duct sleeve — trim it if needed.
Test fit your duct and check that it sits flush.
For mechanical ventilation systems or ducted fans, you may also want to insulate the ducting to prevent heat loss or condensation build-up.
Seal around the duct with exterior-grade silicone or expanding foam for an airtight finish.
Screw the external grille to the wall (use plugs if needed).
Fit the internal fan, vent flange, or backdraft damper.
Ensure airflow is unrestricted and test the extractor or fan.
Always use a wall scanner or detector to check for wires or pipes before drilling.
Wear proper PPE — safety goggles, dust mask, gloves, and ear protection.
If you’re drilling near windows or up high, make sure to use secure ladders or scaffolding.
Take your time — a clean, well-drilled hole makes the final installation far easier and neater.
Still unsure? Bring your measurements into A-Z Hire and the staff can help you choose the right size core bit for your vent job.
Drilling a wall vent might seem like a big job — but with the right gear, good planning, and a solid step-by-step guide, it’s completely manageable.
Here’s why it’s worth doing it properly:
Better airflow = fresher air and less moisture in your bathroom, kitchen, or utility room.
A neat, weatherproof vent hole adds value to your home and keeps your install looking professional.
You avoid damage or repairs later by drilling cleanly and sealing properly.
Hiring the right tools from A-Z Hire means less hassle, lower cost, and no need to store bulky equipment.
So, if you searched for “how to drill a vent hole in my wall,” this guide should cover everything — from safety checks and marking out to cleanly drilling and installing the vent for proper airflow.
