When building a brick wall, choosing the right type of fastener is crucial for ensuring the structural integrity and longevity of the wall. There are several factors to consider when selecting fasteners for brickwork including the thickness of the bricks, the need for adjustability, resistance to corrosion, and cost. The most common fasteners used in brick wall construction are mortar, metal ties, screws, and adhesives. Each has their own advantages and disadvantages depending on the specific requirements of the project. This article will provide a detailed overview of the best options for fastening bricks together to build a durable and long-lasting brick wall.
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Mortar
Mortar is a mixture of cement, lime, sand and water that has been used as a fastening agent in brickwork for centuries. It is applied between the horizontal and vertical joints of bricks and allowed to harden, bonding the bricks together due to its adhesive properties. Mortar has remained the most commonly used fastener for brick walls because of the following advantages:
– Strong compressive strength – Hardened mortar can withstand up to 1800 psi of compressive force, providing substantial strength to resist shifting and settling bricks. This high compressive strength comes from the cement which undergoes a chemical hardening process.
– Flexibility – Mortar joints allow slight movement between bricks which is important for relieving stresses on the wall during natural expansion and contraction cycles. This flexibility prevents cracking.
– Water resistance – Mortar is water-resistant, preventing moisture infiltration into the brickwork. Good water resistance depends on proper curing of the mortar after application.
– Economical – Mortar is relatively inexpensive compared to other brick wall fasteners. The basic ingredients – cement, lime, sand and water – are readily available.
– Familiar to builders – Contractors are very familiar with working with mortar for bricklaying. Proper mortar installation techniques are well-established.
– Aesthetics – Mortar joints provide an attractive decorative look that is part of classic brick wall designs. Different mortar joint styles can be used for unique appearances.
The main disadvantage of mortar is that it can crack, crumble and fail over time due to ground movement, inadequate curing, damage from freeze-thaw cycles, or poor initial installation. Mortar joints need periodic inspection and repair by repointing. Overall when properly mixed and installed, mortar is usually the best and most cost-effective fastening option for brick walls.
Metal Ties
Metal ties are also commonly used in brick wall construction to provide additional structural reinforcement by securing facing brickwork to backing walls. There are two main types:
Corrugated Wall Ties
These are galvanized or stainless steel strips about 22 gauge thick and 1 inch wide that are installed between brick courses. The corrugated shape provides flexibility while the metal composition offers high strength. They are typically embedded in the mortar joint, anchored into the backing wall and bent to provide vertical continuity between courses. The main advantages of corrugated metal wall ties include:
– Strong connection – The metal ties firmly interlock facing brickwork with block or concrete backing walls using mechanical fastening. This creates an integrated structure that resists separation.
– Flexibility – The corrugated shape allows slight movement between the brick façade and backing wall which prevents cracking from settlement.
– Thin profile – The thin metal strips take up little space in the mortar joint and do not interfere with brick placement.
– Durability – Galvanized or stainless steel has excellent corrosion resistance for long service life.
– Economical – Corrugated metal ties have a relatively low material cost.
– Easy to install – Metal strips are easily secured into backing walls and bent into position as bricks are laid.
The disadvantages are that the thin metal can potentially bend or fail if subjected to excessive tension. The limited width also provides less bearing surface than wide joint reinforcement. Metal ties require proper spacing between courses and anchoring into the backing to provide full effectiveness.
Joint Reinforcement
Joint reinforcement consists of wide vertical strips of galvanized steel that span the entire width of the wall to connect facing and backing wythes. Two common types used in brick walls are ladder and truss joint reinforcement.
Ladder type features multiple horizontal rods welded onto two vertical side rods which resemble a ladder shape. The horizontal rods are embedded into the mortar while the vertical rods extend the full height of the wall.
Truss joint reinforcement uses a diagonal rod welded between two vertical side rods for an inverted truss design. This provides lateral stability and resistance to tension forces.
The advantages of wide joint reinforcement are:
– Maximum strength – The full width design provides a large surface area for superior tension load capacity.
– Continuous vertical spans – The uninterrupted vertical rods provide continuous structural reinforcement for the full wall height.
– BACKUP WALL ANCHORAGE – Horizontal tabs allow anchoring into the supporting wall across the entire width.
– DURABILITY – Hot-dipped galvanizing prevents corrosion even if exposed to moisture.
The width and size of joint reinforcement does make it more difficult to properly embed into mortar joints during bricklaying. Proper placement is crucial to achieve effective structural performance. The material cost is also higher than standard narrow wall ties. Overall, wide joint reinforcement provides very strong anchoring for multi-wythe brick walls when properly installed.
Screws
Screws are sometimes used to attach brick veneer facades to wood or metal stud backing walls. Common types include:
Masonry Screws
These are specialty screws designed for fastening into brick materials using star or hex drive recessed heads. They have hard carbon steel cores with sharper threads than standard wood screws. This provides good holding power when driven into the holes or grooves of bricks. Plastic sleeve anchors are sometimes used which have an outer sleeve that expands when the inner screw is tightened.
Tapcon Screws
Tapcon screws are designed specifically for fastening into concrete, block and stone materials. They have a patented chamfered head with special carbide tips that drill into masonry while providing steel threads for clamping strength. The name Tapcon comes from an abbreviation of “tapping concrete” describing its functional advantage.
Some of the benefits of using Tapcon or masonry screws include:
– Strong holding strength in brick – Tests show that properly installed masonry screws can resist pullout loads over 500 pounds in brick materials.
– Quick installation – Holes can be pre-drilled or screws driven directly into brickwork where they tap their own matching threads.
– Adjustability – Loosening or retightening screws allows vertical or horizontal adjustments when installing brick veneers.
– Various lengths – Screws are available in lengths from 1 inch up to 6 inches to accommodate different wall assembly depths.
– Cost – Screws are relatively inexpensive fasteners for brick wall construction.
– Minimal mortar displacement – Small screw holes displace less mortar compared to larger anchors.
– Corrosion resistance – Most masonry screws have coatings or stainless steel composition for durability in masonry applications.
The limitations are that care must be taken to not split brick faces by over-tightening screws. Pre-drilling and proper torque control prevents this. Screws also provide less shear resistance for walls that require substantial lateral load capacity. Overall screws present a fast, adaptable method for attaching brick veneers to backing walls.
Adhesives
High-strength construction adhesives are sometimes utilized to attach brick veneers to wood or steel framed walls. This method is faster than traditional mortar building techniques. Epoxy or polyurethane-based structural adhesives work well for brick because they:
– Cure rapidly to hold bricks in place without temporary support
– Produce high bond strength to resist wind and impact loads
– Allow some flexibility to accommodate movement and thermal expansion
– Resist water and chemical degradation
– Provide insulation against vibration and noise
– Will work on wet, damp or frozen surfaces
– Are easy to apply with standard caulking guns
– Come in various formulations for different temperature conditions
The drawbacks of construction adhesives for brick veneer applications include:
– Potential for high material costs depending on product used
– Bond strength can deteriorate over time from UV exposure if not shielded
– Limited vertical adjustment after bricks are set compared to screws
– Permanent bond makes bricks difficult to remove or replace
– Special surface preparation and cleaning required
– Fire resistance may not be adequate for some assemblies
When used properly, high-strength adhesives can provide excellent adhesion for anchoring brick veneers. However, traditional mortar or mechanical fasteners are more commonly used.
Comparison of Brick Wall Fasteners
| Fastener Type | Holding Strength | Adjustment Ability | Moisture Resistance | Cost |
|---|---|---|---|---|
| Mortar | High | Low | Good | Low |
| Corrugated Ties | Moderate | Moderate | Good | Low |
| Joint Reinforcement | Very High | Low | Excellent | Moderate |
| Screws | High | High | Moderate | Low |
| Construction Adhesive | High | Low | Good | High |
Conclusion
For most standard brick walls, mortar remains the optimal fastening method. It provides excellent compressive strength between courses while allowing slight movement. Mortar also has good water resistance and the lowest material cost. Properly installed with quality technique, mortar can last for decades. Where additional lateral load resistance is needed, corrugated or joint reinforcement ties anchored into the backing wall provide added structural strength. For thin brick veneers, screws give strong holding power while allowing adjustability and faster installation compared to mortar. High-strength adhesives also offer quick rigid bonding but at higher cost. The proper selection depends on the structural loads, wall movement, moisture exposure, and budget. An experienced brick mason can recommend the ideal fastening system for a brick wall to provide lasting structural integrity. With the right fasteners properly installed, a brick wall can provide beauty, durability and lasting performance for buildings.