Have you ever faced difficulties while trying to drill into your wall at home? Having trouble hanging up your “Starry Night” reproduction on the living room wall? Need to install a mirror in the kitchen but you just can’t seem to get the nails in? Ever wondered why?
We were curious too and this is what we found out:
Depending on which area you reside in as well as when your house was built, the type of materials and engineering techniques employed by the contractors vary. For old school homes that were built before the 90s, contractors in Malaysia tended to use bricks, primarily red bricks with cement. These building blocks are generally easier to drill into because even though most bricks have great compressive strength: up to 6000 pounds per square inch for house bricks, they are made from a more uniform material that does not come apart when subjected to pressure from drilling. Other than the material cored out from drilling, the surrounding area does not crumble so easily and the brick tends to stay intact.
Homes built after the 90s in Malaysia however, particularly condominium units, are built entirely out of concrete as local home renovation contractors opted for materials that are easier to mold and set faster. Concrete has a pretty high compressive strength: between 4000-7000 pounds per square inch in residential walls but the tensile strength of concrete is much lower than that of brick. Upon being subjected to high pressure from drilling, unilateral stress causes the much less uniform composite of concrete to crumble away around the drill point. This causes the concrete to flake away causing the nail or screw to shift in place, or eventually pop out when the integrity of the concrete gives way. The older and more cured the concrete is, the harder it becomes and the more brittle and difficult it will be to drill into.
Types of drilling equipment used
What most homeowners have access to are standard issue power drills or a complete set with multiple drill bit types and heads. Most of us would have a pistol-grip power drill which is not exactly the right tool for the job when it comes to drilling into concrete. Pistol-grip power drills are best used for drilling through wood, foam, certain types of cement or metal.
So, what works for concrete?
What you actually need to drill through concrete is a hammer drill coupled with a good masonry drill bit. Also known as a rotary hammer, it uses a hammering action that easily pulverizes brittle yet difficult-to-compress material such as concrete with relative ease. The only problem is, hammer drills are not as common as pistol-grip drills and are slightly more expensive as well. If you are stuck with a pistol-grip drill, you are up for a challenge. In this case, it’s better to work with renovation specialists and professional contractors who have the right equipment and skills.
But if you are going to use a pistol-grip drill anyway, ensure that you have a really good masonry bit. Masonry drill bits are the best drill bits for penetrating concrete.
Wall plugs are brilliant for securing a nail or screw to stop the brittle concrete bits from coming out of the wall. Use wall plugs of up to 10-12mm. Use the wall plug to measure this length on the drill bit and don’t exceed it, or the screw or nail head will be embedded in the wall. Most wall plugs are made out of plastic but a carpenter would use wooden wall plugs that are better for certain porous concrete walls.
Use a low speed and apply the right amount of pressure to ensure a steady and straight drill hole. The trick is to not rush the process as pistol-grip drills are not designed to get through concrete quickly. If you can’t adjust the speed on your drill to the right speed, the drilling process will become messy and will just leave a gaping hole that bleeds concrete bits.
The drilling process takes a lot of patience and expertise as well as the right tools and knowledge of the wall plan as heavier density concrete or penetrating beams could require stronger grade drills and drill bits. Sometimes it is best to use the services of your renovation contractor. Most interior design companies in Malaysia are well versed with the types of walls and how to drill into them.