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How to Drill a Hole in a Brick or Block Masonry Wall – A Step by Step Guide

(1) This in depth guide will help walk you through the process of drilling holes in masonry walls.

A mach construction rendering showing a concrete masonry wall with a hole.

Intro: Drilling Holes Through Masonry

Drilling a hole through a finished masonry wall may seem like a daunting task, but with the right tools and techniques, it is most certainly a DIY friendly project. Whether you need to mount a shelf, install plumbing or hvac rough-ins, or just simply need a hole in the wall, our step by step guide will help you navigate the process successfully. Before you begin, you need to make a plan. This plan will include what you want your final finished product to look like and how it works. It also includes gathering the necessary tools and safety precautions you can take to ensure a smooth drilling experience.

(2) Understanding Masonry Wall Density & Composition

stack of cinder blocks outside in the woods

Types of Masonry Walls

Before you go and start drilling, it is imperative that you understand the composition of typical masonry walls. Masonry walls are typically made of dense materials like brick, concrete, or stone. These types of materials are very strong and will require specific tools and use specific drilling techniques to penetrate. It is NOT the same as drilling through drywall or wood products. Choosing the proper drill bit and drilling approach will prevent damage to your substrate and ensures a nice clean cut hole. 

Thick, Tough, and Unforgiving

Masonry and concrete walls are extremely tough and durable, but they also have their weak points. For instance, a cinder block (cmu, concrete block) is very strong but are typically not filled solid. They have an inner webbing, but holes through each block. If you take a heavy hammer and hit the part of the block that is not solid, it can crack and break the whole block, usually at the joints.

A cinder block (cmu, concrete block) is very strong but they are typically not filled solid. They have an inner webbing, with holes through each block. If you take a heavy hammer and hit the part of the block that is not solid, it can crack and break the whole block, usually at the joints.

A brick and block masonry wall comes with it’s own unique challenges. Some are built with solid concrete block paired with brick for the exterior. So you have two different solid materials to bust through. Not many people know this, but there is an air space of about 1″ in between your brick veneer and your concrete block. Brick is very dense, but is actually pretty easy to break.

Concrete walls (or floors) are probably the hardest of these three materials to drill through. It also makes a huge mess. (Concrete dust flies everywhere and is not safe for you to breathe in.) Concrete is very dense and doesn’t crack as easily as brick or blocks. Concrete is typically 4″-8″ thick in floors and walls respectively.

(3) Tools You Will Need to Drill

safety gear on workbench with tools

Tools For The Job

Depending on your budget and how you want to drill the hole you need, these are the tools that you should acquire. Later, I will explain the two different methods of drilling. This will help you figure out which method is best for you. Then you can buy only the necessary tools for your chosen method.

A powered hammer drill is like a super-fast automatic hammer that makes drilling holes in tough materials (like concrete) easier and faster. It hammers and drills at the same time. It’s commonly used in construction and DIY projects.

There are many different types of drill bits on the market. The only ones that you will want to use for drilling in masonry include: Percussion/Hammer drill bits, Masonry drill bits with carbide, or a hole saw bit that can drill through masonry.

We will be using a bubble level to make sure our project is “level on a vertical and horizontal plane”. If you are making a circular hole, this is not necessary. This is strictly for rectangular and square hole shapes. Read down below to find out how to do this.

A small metal mallet or a heavy hammer is needed when not using the hole saw bit. You will need the punching power of one of these hammers to “pop” out the masonry inside the marked area once you have the perimeter chipped away.

A cold chisel is a hand tool used for cutting and shaping metal, masonry, and other hard materials. It is made of tempered steel and has a sharp cutting edge on one end. We will be using it to chip away a “score” around your hole line. Take your hammer and hammer the sharp end into your hole line all the way around to complete the circle.

There aren’t many projects when a tape measure isn’t needed. We are going to use the tape measure to find and mark where the hole needs to be. You can also measure after cutting to ensure you have enough space for whatever you are installing into the wall. Any tape measure will do. You can also use a ruler or a straight edge as they don’t flex or bend.

Plain and simple, we need a pencil to mark where you want to drill the hole in the masonry wall. If you have a cup or something round that is the same size as the hole you want, you can use it to trace a perfect circle on the wall as a template. Construction pencils have a very thick lead, so it doesn’t break.

Shop vacs are a godsend. They are portable and will suck up anything! You are going to want to have this tool around to clean up all of the masonry dust that your hole drilling creates. It will even pickup small pebbles as well and other dust and trash that might be laying around. It even sucks up water!

(4) Recommended Safety Gear

first aid kit safety gear

Think First. Think Safe.

When using power tools, you should always think safety first. Things you should protect include your eyes, your ears, your skin, and your lungs. Drilling into masonry can cause a lot of particulate dust to fly in the air, which is bad for your eyes and your lungs. Loud noises from hammering or drilling can be harmful to your hearing.

 Concrete and masonry debris is coarse and dense. You will want to protect your eyes and skin from cuts from flying debris. You also need a way to patch yourself up if you do get injured, but don’t necessarily need to go to the hospital. Buy a good first-aid kit and keep it on your job site.

Safety goggles are like clear sunglasses that will protect your eyes from small debris, dust, sand, and anything that flies up towards your face. Anytime that you are using power tools, you should wear your eye protection, especially if you are working overhead or in areas with limited airflow.

When masonry products are drilled into they release a massive amount of particulate matter into the air. You should wear a surgical mask or a 3m respirator to protect your lungs from all of the particulate matter floating around. Look up silicosis, you don’t want it. Can cause permanent lung damage!

Using a hammer drill can be very loud. If you are in an enclosed space, it is even louder. If you have sensitivities to loud noises, or you just want to protect yourself from hearing damage or loss, you will want to wear ear plugs to protect yourself.

Wearing long clothing that covers up most of your skin is the best protection from scratches, scrapes, burns, skin irritations, sunburn, etc. It might make you a little warmer, but it’s worth it to avoid injury. Nothing stops a job faster than injured workers.

You don’t necessarily have to have “non-slip” shoes, but you definitely want to make sure the shoes you are wearing have plenty of tread and are not naturally “slippery” shoes. Some tennis shoes have a sole that wears down fast, leaving you with a slick bottom. Falling down on a concrete floor sucks.

A hard hat is not typically necessary for DIY home projects. Any time that you are working above your head, there is a risk for falling debris. This is when you want to wear a hard hat. It is still important to be aware of debris that might fall on top of you or others. Falling debris can also damage your project.

Hey, no one ever plans on getting hurt, right? Sometimes, it just happens. You want to be prepared for cuts, scrapes, bruises, and irritations. A general first-aid kit is perfect for this. If you break a bone, or chop something off you are definitely going to want to go to the hospital instead of DIY’ing your injuries.

We keep our cell phones on our person most of the time these days. It is a vital tool that you can use in case of an accident. If you are working by yourself, it gives you the option to call for emergency services if you need help. It’s always best to work with a partner, that way you can look out for each other.

(5) Step-By-Step Guide: Using Power Tools or a Cold Chisel and Hammer to Drill a Hole

Step 1: Mark & Prepare the Wall

Accurate measurements and marking are crucial for drilling success. Use a pencil and a level to mark the spot where you want to drill the hole. Double-check the position to avoid costly repairs or having to bust two holes in your wall and then repair one. Additionally, clear the area where you will be working to ensure easy access.

how to mark your hole drilling a hole blog post2

There are typically two different  types of holes you would be drilling into a masonry wall. You have square or rectangular shaped holes, and you have circular holes. To mark for a circular hole, all you need to do is find the center mark and then use a compass or a circular object to trace the shape to the desired size. 

A square or rectangular hole will require the use of a bubble level. First, mark the area where you want the bottom of your hole to be. Find the center and the two bottom corners and mark them with the pencil. Next, you will measure upwards to find your top level corners. Use the bubble level to draw level lines. Check your measurements and total size to ensure they are correct. 

Step 2: Drilling the Hole

Before you start to drill or hammer the masonry wall, just know that the results you get from manually drilling a hole with a cold chisel and hammer are going to be directly related to the time and care you take while drilling the hole. 

which drilling method should you use drilling a hole blog post2

Step 3: Manually Drilling The Hole

In order to create an accurate hole in your masonry wall, you will need to use your cold chisel and hammer to tediously create a “score” mark on the template lines you drew earlier. Take your time and make this score line as accurate as possible, tapping lightly so you don’t break the whole block. This will give you the best end result.

One of the hardest things to do is making sure the hole on the back side of the wall matches up with the hole on the front side of the wall. After you have your template “scored” you can take and carefully hit the middle of where your hole is. This will loosen or knock out part of the hole, and will allow you to more easily break out the remaining masonry.

The initial drilling will knock out most of the material, but you will need to focus your efforts on cleaning up the lines to make sure there are no irregularities or small pieces of masonry that will block whatever you are trying to insert into the hole. The best way to do this is with very light tapping with the cold chisel and you can even use a file to smooth out irregularities in your cut.

After you have completed drilling the hole, take your duct or whatever you are installing through the wall and do a “dry fit” to see if the hole is the appropriate size. After the dry fit, make the necessary adjustments to make it fit perfectly. If you knocked out a little bit too much, you can usually just fill these holes with expanding foam or silicone.

With your newly drilled hole inside your masonry wall, there will be some clean up required. The easiest way to clean up this type of debris is to run a filtered shop-vac around the area. It will get 90% of the dust and debris that came from the drilling. You will need to remove large chunks with your hands. It also helps to use a wet cloth to wipe the area (floor and wall) to remove any excess dust and debris.

Step 4: Drilling With Power Tools

As shown earlier, you will need to use a bubble level and pencil to mark your hole on the wall. This is just a template for you to drill by. If you are using a hole saw masonry bit, you just need to mark the center. If you are using a hammer drill and a regular masonry bit to “poke” out the hole, then you will need to measure and mark the entire template.

For power drilling holes, you will need a hammer drill, some masonry bits and/or a hole saw masonry bit. I believe the hole saw bits go up to about 2″ max in diameter. It’s also beneficial to have a cold chisel and a hammer around to fine tune the hole after you have drilled through with the hammer drill. Make sure you have a portable light or adequate room lighting so you can actually see what you are doing.

When using a hammer drill, you want to make sure it is in “hammer” mode so that it will hammer instead of only drill. This will make the job go much faster. Also, you need to apply some pressure towards the wall to help the bit bust through the masonry. I always start in the center to bust a larger portion of the hole away. This will give you access to the edges and the back side of the wall and will make refining your edges much easier and overall will produce a better end result.

Just as you do when manually cutting a hole into masonry, you will need to use a file, a cold chisel, and a heavy hammer to chip away the imperfections so that the hole is smooth, clean, and the right size. Take your time, get the right angle, and use the chisel to clean up all of the edges on the front and rear sides of the masonry wall.

Cleaning up the project area is a little different when you use a hammer drill to bust a hole. It’s the same process as with manual drilling with a chisel, but there’s going to be a LOT more dust to clean up. Do not use fans while you are drilling. They only make the dust fly up into the air. Make sure you have your respirator / mask and eye protection on during this process. Particulate matter is very dangerous to both your lungs and eyes and we want to protect those.

The End: Drilling Holes Complete

When it comes to drilling holes in masonry walls, it’s definitely a do-able diy project for most anyone. As long as you take the proper safety precautions and are meticulous about your measurements, it will turn out great! The longer it takes you, the better it will look and work.  Good luck on your first hole drilling. You got this!

“Make sure before you break through that you want to see what's on the other side."

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We are construction junkies and love educating people on the conventions and trends in the residential construction space. We use our blog to post informational articles, how-to’s and sometimes show off our own construction projects. We love the transparency and it really does give non-construction folks a view into the industry.


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