Flemish Bond vs. Rat Trap Bond: A Breakdown
Flemish Bond vs. Rat Trap Bond: A Breakdown
Both Flemish and Rat Trap bond are bricklaying patterns used in construction, but they have key differences:
Flemish Bond
- Appearance: Alternates headers (short ends exposed) and stretchers (long sides exposed) in each course (row) creating a continuous, repeating pattern.
- Types:
- Single Flemish: Headers on the front face, stretchers on the back.
- Double Flemish: Headers and stretchers alternate on both faces.
- Strengths: Strong, visually appealing, good for load-bearing walls.
- Weaknesses: Requires more bricks and mortar, not ideal for thermal insulation.
Rat Trap Bond
- Appearance: Uses “rowlocks” (bricks laid on their edges) for the inner and outer faces, with “shiners” (bricks laid flat) bridging the gap. Creates a cavity within the wall.
- Strengths:
- Reduces brick and mortar usage by 20-35% compared to Flemish bond.
- Improves thermal insulation due to the cavity.
- Easier to construct with repetitive pattern.
- Weaknesses: Not as strong as Flemish bond for load-bearing walls. Requires specific skills for laying the cavity correctly.
Choosing the right bond
The choice depends on your project needs:
- Load-bearing walls: Flemish bond offers superior strength.
- Non-load-bearing walls: Rat trap bond is more cost-effective and provides thermal benefits.
- Aesthetics: Flemish bond offers a classic, decorative look.
- Budget and construction skills: Consider material costs and complexity of each bond.
Additional considerations
- Some building codes may have restrictions on specific bond types.
- Consult with a qualified mason for expert advice on selecting the best bond for your project.