Wall Openings You will learn about the types and function of wall openings. You will learn about the components parts of each opening and why they are there. Look at the front of your house or school building. Look at the doors and windows. Make a list of what you see. Openings have to be included in walls to provide: • Ventilation – the circulation of fresh air in a building • Sunlight • Aesthetics – the attractiveness of a building. Function of wall detailing including sills, jambs, thresholds, heads, lintels etc. Prevent damp transfer – moisture getting into the building through the opening. Continuity of insulation – no gaps in the cavity wall to allow warm air to escape. Distribute the load from the building around the wall opening to Maintain structural integrity – keep the building stable and able to support its own weight.

Components of a wall opening From the construction point of view, the key issue is the detailing around openings; this must ensure that no moisture or damp can penetrate and must protect against the creation of 'cold bridges.

Head and Lintels Steel Lintel The head is the part of the opening, such as a door or window, that has the task of supporting the load of brickwork above it. As well as carrying the load, the head has to transmit the load to the jambs at the sides. Stone Lintel Lintels or beams are used for the construction of such heads These can be made from different materials depending upon the load being supported. If a lintel is not used the weight of the brickwork above will case collapse and cracking of the brickwork and building.

Jamb Jamb This is the vertical part of the wall opening. On a single door or window opening, one side is known as the hanging jamb, and the other is the closing or shutting jamb. There are several different types of jamb treatment, depending on the type of wall. On a solid wall, the jambs are bonded to give them the shape and strength; in cavity walls, the area where the opening is to be closed by a timber frame, incorporating a damp-proof course (DPC) Jamb Building Regulations require that the detailing of the vertical DPC, cavity closure and insulation is particularly important. If this is not done correctly, 'cold bridges' could be created, and moisture or damp could penetrate.

Typical Jamb Treatments

Sills and Thresholds Look at any window or door, and you will see that it has a piece of material below it - plastic, concrete or timber. This material is shaped to allow rainwater to run off, away from the opening. This is called a sill or threshold. It does not have to carry any load, but is simply there to get rid of the rainwater that runs down the surface of the door or window.

Cavity Tray and Weep Holes These are a damp proof course inside a cavity wall designed to funnel away any water that gets into the cavity. The water exits the cavity through weep holes left in the brickwork.

Cavity Closer Cavity closers are used to seal up the cavity around any opening. This ensures that cool air does not enter the cavity and warm air does not escape. This improves the insulation properties of the cavity and keeps the building warmer.

1. Describe the three functions of a wall opening. 2. Explain the four functions of wall detailing. 3. What is the HEAD of an opening and what component is used to create it? 4. Explain how lintels work and what they can be made from.

5. If a lintel is broken or not fitted what would the homeowner notice about the building around the wall opening? 6. Explain what a Jamb is together with how, where and why they are used. 7. Explain the difference between a sill and a threshold. 8. Explain the purpose of sills and thresholds.

9. Describe a cavity tray and explain its function in a cavity wall. 10. Describe the function of a cavity closer. 11. What is the purpose of a weep hole?