Project details
Skill
Cost
Estimated Time
In this Build It, Ask This Old House mason Mark McCullough teaches Kevin O’Connor how to patch holes in a tough surface.
Anchor holes in brick are more common than you might think. As Mark McCullough points out, they come from all sorts of sources: holiday lights, hanging stockings, exterior signs on commercial buildings, and even decorative elements around fireplaces. The good news is that with the right color-matched product — whether a pre-tinted putty or a custom-dyed mortar mix — most homeowners can tackle this repair themselves.
Pro Tip: Mark McCullough cautions that when mixing mortar with dye for color matching, thoroughness is essential: “If you don’t mix this stuff over and over and over, the dye clumps up and you’ll get a heavier set in certain locations.” He also advises being careful not to add too much water to the mix.
Two Methods to Know: In the episode, Mark McCullough explains that there are two methods he really likes for filling anchor holes in brick. The first involves matching your brick color using a tinted putty that comes pre-colored — just add water. The second uses a standard mortar and sand mix with dye added to achieve the right color match. As Mark notes, color matching is a critical part of getting the repair right: “Because this is such a difficult task, it’s never gonna be perfect. So if I can’t get as close as I would like, I do have other methods that are gonna bring me closer to what I want.”
Steps for Patching Holes in Brick
- Find a mortar mix or compound that matches the existing brick as closely as possible (an exact match isn’t likely)
- Using water sparingly, mix the compound or mortar mix to a thick putty-like consistency. It’s better to add small amounts of water a little at a time than trying adding material to a wet mix.
- With a bit of the compound on a trowel, use a hex key or something similar to pack small amounts of the compound into the hole until the hole is filled to be slightly proud of the brick surface.
- Use a trowel to flatten the compound against the brick. Press down and use a small circular motion—don’t drag the trowel across.
- Using a damp sponge, press the sponge against the patched hole and then lift it straight off the brick to mimic the rough surface of the brick.
Prevent Cracking: Before applying your patching compound, lightly dampen the inside of the hole and the surrounding brick with water. A dry brick will suck the water out of new mortar, causing it to crack rather than cure properly. A light spray or a pass with a wet brush is all you need — you don’t want standing water, just a damp surface.
Why Packing Matters: While doing a patch job, you have to make sure that you push the mortar in as far as possible, because you don’t have the opportunity to lay a bed joint the way you normally would when building a wall. Also keep in mind that fresh mortar will appear darker than the surrounding brick — but after about 28 days when the mortar fully cures, it should blend in and match the existing surface much more closely.
Shopping list
- Mortar mix or putty
- Dye for mortar
- Sponge
- Bucket
