Lintels are crucial structural elements spanning openings in walls to support the weight above. They distribute loads evenly, preventing stress on windows and doors. Lintels come in various materials, each suited for different applications and building types.
Proper lintel selection and installation are vital for structural integrity and longevity. They play a key role in load-bearing, moisture management and thermal performance.
What Are the Best Methods for Installing Lintels for Windows in a Timber Frame Construction?
When installing lintels for windows in timber frame construction, follow these best practices for top results.
- Choose the best lintel type: Timber frame lintels or steel lintels designed for timber frames are ideal. Ensure they're compatible with the frame's load-bearing capacity and thermal performance requirements
- Ensure proper sizing: Calculate the load and span to select the correct lintel dimensions. Factor in wind loads and any weight from cladding or interior finishes
- Create a level bearing surface: Use shims if necessary to provide even support. This prevents uneven settling that could lead to cracks or misalignment
- Secure the lintel: Fasten it to the timber frame using appropriate fixings. Use galvanised or stainless steel fixings to prevent corrosion and ensure stability
- Allow for movement: Leave a small gap between the lintel and window frame for settling. This gap should be filled with a flexible sealant
- Integrate with the vapour barrier: Properly seal around the lintel to maintain the building's airtightness. Use purpose-made tapes or membranes to create a continuous air barrier
- Insulate: Fill any gaps around the lintel with insulation to prevent thermal bridging. Use compressible insulation to allow for minor movements in the structure
How Does the Installation Process Differ Between Concrete Lintels and Steel Lintels?
The installation process for concrete lintels and steel lintels differs in several key aspects. A concrete lintel is heavier and needs more manpower or machinery to lift it into place. Concrete lintels need a full bed of mortar for support and even weight distribution.
A steel lintel, being lighter, is easier to handle but requires precise positioning. Steel lintels often come with built-in damp proof courses. They need end bearings of at least 150mm on each side. Proper insulation is important to prevent thermal bridging with steel lintels.
When Would I Choose a Solid Wall Lintel Over a Cavity Lintel?
Choose a solid wall lintel over a cavity lintel in the below scenarios.
- When working with single-skin or solid masonry walls
- For internal load-bearing walls within a building
- In historical restoration where maintaining original wall construction is key
- When the wall thickness doesn't accommodate cavity lintels
- In situations requiring high load-bearing capacity in a compact design
Solid wall lintels provide robust support in traditional construction methods and are often simpler to install in non-cavity wall applications.
How Do I Properly Support a Wide Opening in a Load-Bearing Wall Using Multiple Lintels?
Supporting a wide opening in a load-bearing wall using multiple lintels requires careful planning and execution. Start by accurately calculating the total load and required span. Consider both dead loads (wall weight) and live loads (roof, floors).
Fit a continuous steel plate beneath the lintels to distribute the load evenly. This plate should extend the full width of the opening and have enough thickness to prevent bending. Ensure each lintel has adequate end bearing, typically 150mm minimum on each side.
Use steel connectors or welds to join the lintels, creating a unified support system. The connection method should allow for thermal expansion in steel lintels. Consider using padstones at the bearing points to distribute the load into the wall below.