How to Drill Into Brick
Drilling into brick is sometimes necessary when hanging pictures or mirrors, lightweight shelves, or cabinets on brick walls. Drilling also comes into play when large holes are needed for installing outdoor outlets or light fixtures.
Drilling into brick can be difficult if you try to use a conventional rotary drill and a drill bit that's not suited for masonry. With the right tools and techniques, this job is quicker and far less frustrating.
Should You Drill Into the Brick or the Mortar?
Given that mortar is softer than brick and easier to drill into, should you actually drill into the mortar instead of the brick?
Mortar's softness does make it easier to drill into. Plus, patches to mortar are less noticeable than patches to brick. But mortar is too soft and unpredictable for hanging or attaching heavy, fragile, or valuable items. Mortar can have voids that aren't visible from the outside of the joint, contributing to its structural weakness.
Whenever possible, drill into the brick, not the mortar. If you plan to drill into the mortar, use a plastic expansion anchor and make sure that anything you hang is lightweight.
Tools for Drilling Into Brick
A hammer drill is the best type of drill for drilling into brick, as well as concrete and other masonry. Hammer drills rapidly pound the hole in a chipping motion while turning the drill bit. Hammer drills impact the work surface at between 20,000 to 50,000 beats or blows per minute (BPM).
Hammer drills are effective and usually are worth renting or purchasing if you have more than a few holes to drill in brick. Hammer drills cost between $200 and $500 to purchase.
The hammer mode can be turned off so that the tool can be used in rotational-only mode. Since hammer drills are big and bulky, they aren't convenient to use as your main rotary drill on a regular basis.
Rotary Drill With Hammer Function
Rotary drills with a hammer function, sometimes called hammer drill drivers, are an alternative option for drilling into brick.
These drills are mainly designed for rotary drilling. With the twist of the plastic clutch collar, they convert to hammer drilling mode. Rotary drills with this feature deliver up to 34,000 BPM.
A carbide masonry bit has a spade-shaped end that helps to dig away the brick. Its grooved flutes force the debris backward. You can buy full sets of masonry bits if you plan to do a lot of drilling into brick. Because masonry bits are fairly expensive, you can buy individual masonry bits.
A lag shield is a secure anchor for hanging items from brick. The anchor slides into the hole in the brick, and the screw is turned into the anchor. Turning the screw expands the zinc-alloy anchor, holding it tightly in place.
Choose a drill bit that is one size larger than the anchor: usually, 1/4-inch or as specified by the manufacturer.
|Lag Shield Size||Drill Bit Size||Weight Rating, Brick|
A shop vacuum is valuable both for clearing brick dust from the hole and for cooling down the drill bit while it is turning. Make sure that the vacuum is fitted with a dust bag and a HEPA dust filter.
Codes and Permits
Drilling into brick itself generally will not trigger any permit requirements in most municipalities. But the project might be part of a larger project that does need permitting, such as installing an outdoor GFCI outlet on a brick wall.
Manufactured veneer brick is much softer than structural brick and may not provide enough support for attaching heavy items. Plus, veneer brick can be as thin as 3/4-inch-thick—too thin for hanging heavy items.
Structural brick walls may have electrical wires running through the inside. If you will be drilling completely through the brick, check for wires. Deactivate power to the area by flipping off the appropriate circuit breaker on the electric service panel.
What You'll Need
Equipment / Tools
- Hammer drill or rotary drill with hammer function
- Mortar bit
- Shop vacuum
- Eye protection
- Hearing protection
- Painter's tape
- Rag (optional)
Turn down the torque on the drill. This slows down the speed of the drill's rotation and provides a better inner gearing ratio for drilling into hard surfaces.
If the drill has an optional hammer mode, turn it on now. Usually, you'll need to turn a plastic collar to the hammer icon.
Make Depth Gauge
The purpose of making a drill depth gauge is to provide yourself with a marker so you know how far to drill into the brick. You will want to drill as far as the length of the screw, plus another quarter inch.
Hold the screw alongside the drill bit, so that the head of the screw and the sharp end of the drill bit are next to each other. Cut off a piece of painter's tape about 1/2-inch wide. Wrap the painter's tape around the drill bit, marking the desired depth of the hole, adding another 1/4 inch of buffer room.
With a pencil, place a mark on the brick where you want to drill the hole.
Drill Hole in Brick
If the brick is very smooth, the drill bit may travel off of the mark point when you turn on the drill. With a hammer and 16d nail or similar sharp device, tap lightly a couple of times to create a shallow hole on the brick face.
Place the end of the drill bit on the brick. Pull the trigger on the drill. As the drill turns, gently push into the brick. Drilling into brick cannot be forced, so let the drill and drill bit do the work.
Clear Hole in Brick
Every now and then, use the shop vacuum to remove brick dust from the hole. If you have an assistant, the assistant can hold the nozzle of the shop vacuum underneath the hole while you are drilling, with the vacuum running. This will reduce dust and keep the drill bit cooler. You may also want to use the rag to wipe away dust.
Attaching Items to Brick With Lag Shields
After drilling the hole in the brick, the anchor is inserted in the hole, followed by the screw.
- Clear the hole of dust one final time. Insert the anchor into the hole as far as you can with your fingers.
- Place the screw in the open end of the sleeve. With the hammer, gently tap the head of the screw to force the sleeve further into the hole.
- Force the end of the sleeve until it is flush with the hole or slightly in, but do not force it more than 1/16 inch into the hole.
- Turn the screw into the anchor as tightly as possible without stripping the head of the screw.
Plastic masonry anchor sleeves are generally good for weights up to 60 pounds. Metal sleeve anchors with attached bolts are used for heavier items.
When to Call a Professional
For attaching structural elements like carports or deck ledger boards, call a general contractor.