How do you fix a loose brick without mortar?

Having a loose brick in your wall or pavement can be annoying and potentially dangerous if it starts to fall out. Fixing it properly usually requires re-mortaring, but this takes time and the right materials. Luckily, there are some quick fixes to stabilize a brick temporarily before you can permanently repair it. Here’s an overview of the common options for a quick-fix without mortar, along with their pros and cons.

How to Tell if a Brick is Loose

Before deciding on a solution, you need to confirm the brick is loose. Look for these signs:

• The brick wiggles, shifts or clunks when you tap it
• There are gaps or cracks around the edges of the brick
• The surface of the brick doesn’t align with neighboring bricks
• You see damaged or missing mortar around the brick

If you spot these issues, the brick likely needs to be stabilized.

Why Proper Repair is Ideal

While the quick fixes below can temporarily stabilize a brick, permanently repairing it with new mortar is ideal for strength and durability. Here’s why proper re-mortaring is the best long-term solution:

• Mortar bonds tightly to seal out water and prevent further damage
• It fills all gaps around the brick and locks it firmly in place
• Mortar restores the structural integrity designed for the wall or pavement
• It creates an attractive, uniform appearance that matches the rest of the masonry

So if you have the time and materials, re-mortaring is always recommended. But when that’s not immediately possible, the following quick fixes can be good temporary solutions.

Friction and Shims

One easy method is to create friction around the brick to hold it in place. You can do this by tapping shims into any gaps between the brick and those around it.

Types of Shims

Look for thin, rigid shims that will wedge tightly into the brick gaps. Some good options include:

• Paint stir sticks – free and readily available
• Wood shims – inexpensive and sold at hardware stores
• Plastic shims – reusable and won’t rot over time
• Steel shims – extremely durable for tight spaces
• Aluminum tabs – slide easily into narrow gaps

Avoid using paper, cardboard or foam, which can degrade and compress over time.

How to Install Shims

The process is straightforward:

1. Inspect around the loose brick for gaps – focus on the tightest vertical spaces so gravity helps wedge the shims in place.
2. Select rigid shims that are slightly thicker than the brick gaps.
3. Use a hammer to gently tap shims into the gap above and below the loose brick. Work in opposing pairs for the best friction.
4. Tap the shims until they are snugly wedged in the gap.
5. Test that the brick is now stable and can’t shift or rock back and forth.
6. Add additional shims if needed to tighten everything up.

When tapping in shims, be careful not to crack or chip the edges of the surrounding bricks. Place a piece of scrap wood against the brick and tap against that if needed to prevent damage.

Tips for Success

Follow these tips to get the best results when shimming:

• Match the shim thickness for a very snug fit.
• Cut tapered shims to match any mortar joint angles.
• Space pairs of shims close together for maximum friction.
• Use the hardest shim material that fits to prevent crushing.
• Tap gently to avoid shifting nearby bricks.
• Wedge diagonally if there are no viable vertical gaps.

Advantages of Shims

This friction method works well because:

• It’s very fast and requires only simple materials.
• Shims can fill gaps of any shape or size.
• It stabilizes without any special tools.
• The brick can still be removed later for mortar repairs.

Disadvantages of Shims

Some downsides to consider include:

• Doesn’t restore full structural strength.
• Can work loose over time as shims compress.
• Moisture can penetrate the gaps around shims.
• May not work well on large or very heavy bricks.

So shimming is only a temporary quick fix. But it can buy you some time until mortar repairs are possible.

Adhesives

Another option is using adhesive to bond the loose brick in place. This creates a tight seal that withstands vibration and moisture.

Types of Adhesive

Look for an adhesive designed for masonry repair. Some good choices include:

• Silicone sealant – flexible, waterproof and won’t harden over time
• Epoxy – extremely strong bond but can be difficult to remove later
• Polyurethane foam – expands into cracks and gaps to seal out moisture
• Hydraulic cement – withstands weather and bonds to masonry

Avoid household adhesives like super glue or construction adhesives, which aren’t formulated for masonry. Be sure to follow the product instructions carefully.

How to Apply Adhesive

Here are the basic steps for applying adhesive:

1. Clean the brick thoroughly to remove dust and dirt.
2. Dry the area around the brick so the adhesive bonds properly.
3. Squirt or trowel adhesive onto the back of the loose brick and surrounding stable bricks or the mortar joints.
4. Push the loose brick firmly into place and hold for 30-60 seconds.
5. Use wooden wedges or clamps if needed to keep the brick from shifting until the adhesive sets.
6. Clean away any excess squeezed-out adhesive before it dries.
7. Allow the recommended cure time before removing supports.

Follow all manufacturer drying, cure time and application instructions carefully. Wear gloves since some adhesives can irritate skin.

Tips for Success

These tips will help ensure a strong bond:

• Pick an adhesive designed for masonry and bricks.
• Apply to clean, dry surfaces only.
• Use enough adhesive to completely fill any gaps.
• Keep the brick immobile while the adhesive cures.
• Brace heavy bricks with supports until fully cured.

Advantages of Adhesive

Adhesive offers benefits like:

• Bonds tightly to stabilize bricks.
• Seals out moisture from gaps.
• Foam adhesive expands to fill cracks.
• Works on damp surfaces once cured.
• Flexible options like silicone allow slight movement.

Disadvantages of Adhesive

Some drawbacks are:

• Brick may still need mortar repairs for full structural strength.
• Difficult to remove adhesive for later repairs, especially epoxy.
• Less effective if the gaps around the brick are too wide.
• Rigid adhesives like epoxy can crack under brick movement.
• Gaps may need to be sealed to contain expanding foam.

So adhesives provide a semi-permanent stabilization solution, but aren’t a full substitute for mortar repairs.

Supports

You can also stabilize a loose brick by supporting it from underneath or behind. This takes the weight off the damaged mortar.

Types of Supports

Supports should be rigid and sturdy. Good options include:

• Steel mending plates – attach to the brick and wall for support
• Wire mesh – inserts behind the brick as a barrier
• Wood braces – wedge into place for support
• Concrete – can be poured to fill behind the brick
• Plastic or composite shims – tap into place for support

Avoid soft materials like cardboard that will compress and loosen over time.

How to Install Supports

The installation method depends on the type of support:

• For mending plates – attach one side with adhesive or anchors to the brick, mortar the other side in place on the wall.
• For wire mesh – cut mesh panels to fit into the empty space behind the loose brick.
• For wood braces – cut wood strips to wedge vertically into any gap behind the brick.
• For concrete – build a form behind the brick, seal the gaps, and pour premixed concrete.
• For plastic shims – tap rigid shims into place vertically behind the brick.

Tips for Success

Follow these guidelines when using supports:

• Make sure the support fills the full space behind the brick.
• Cut wood or shims slightly long and wedge them in tightly.
• Look for residual cracking or mortar damage after installing supports.
• Check regularly that shims or braces haven’t worked loose.
• Take extra care when supporting a cracked brick.

Advantages of Supports

Key benefits of using supports include:

• Transfers weight off damaged mortar.
• Can fill larger gaps behind bricks.
• Rigid supports won’t loosen or compress.
• Often a simple, low-cost solution.

Disadvantages of Supports

Some potential cons to note:

• Doesn’t create a waterproof seal like adhesive.
• Loose shims may still allow slight brick movement.
• Can damage brick if installed improperly.
• May not work well if there is limited space behind the brick.

As with other quick fixes, supports help stabilize but don’t permanently repair mortar issues.

Comparison of Options

Here’s a quick comparison of the pros and cons for these three DIY solutions:

Method	Pros	Cons
Shims	Very fast and simple Readily available materials Allows later removal	Not a permanent fix Can loosen over time Doesn’t seal out moisture
Adhesive	Bonds brick tightly Seals gaps and cracks Works on damp surfaces	May still require mortar repair Difficult to remove some types Brittle adhesives can re-crack
Supports	Transfers weight off mortar Can fill larger gaps Simple, inexpensive materials	Doesn’t create a water barrier Loose shims may still shift Can damage brick if not done properly

As you can see, each has pros and cons to weigh based on your specific needs.

Combining Fixes for Maximum Holding Power

For loose bricks that still wobble and shift even after applying one of these methods, you can combine two fixes for extra stability:

• Wedge shims and apply adhesive over top.
• Install supports and fill remaining gaps with adhesive.
• Use adhesive and tap shims into place until it cures.

Layering two approaches provides added insurance. This maximizes friction, support strength and waterproofing to keep the brick locked in place. Monitor these combinations closely and replace any failing shims, wood or other supports as needed.

When to Call a Professional

While the fixes covered in this article can temporarily stabilize a loose brick, permanent repairs require re-mortaring by a qualified masonry contractor. Get professional help if you experience:

• Multiple loose or shifting bricks in one area.
• Loose bricks over doors, windows or other openings.
• Loose bricks in the top few rows of the wall.
• Damage, cracking or deterioration of multiple bricks.
• Signs of sinking, separating, bowing or leaning in the wall.
• previous repairs have failed.

Extensive loose brick issues like these indicate more serious structural problems that require an expert eye. The DIY fixes in this article are not intended as substitutes for proper repointing of deteriorating mortar or addressing underlying wall damage. They are temporary measures to stabilize a single problem brick while you arrange for full repairs.

Conclusion

Loose bricks are common in older brick walls and pavements as mortar deteriorates over time. While permanent repairs require re-mortaring, various temporary fixes are available if you need to quickly stabilize a single loose brick. Wedges and shims use friction, adhesives provide bonding strength, and supports hold the brick in place until repairs can be made. Each has pros and cons to consider. In extreme cases, combining two methods can add extra holding power. But for extensive damage or signs of structural issues, it’s best to call in a professional masonry contractor to properly re-mortar bricks and restore structural integrity. With the right solution, you can stabilize a problem brick and prevent further damage until full repairs are possible.