Getting the sequence right

By - , Build 81

If work is carried out too early or too quickly it may have to be removed to allow another trade to complete their part, adding costs and delays to the job. Getting the sequence right is crucial for a good job.

Figure 2: Correct installation of reverse-slope eaves.

Programming on-site building work can be a difficult task. There is the weather to contend with, the Monday morning blues, the supply of building materials and there are the demands placed on subcontractors by the other contractors they work for. Unacceptable construction practices on site are often an attempt to overcome these perceived programming difficulties.

A number of potential problems can arise from the way work is carried out or sequenced on site. The work schedules of other trades can be disrupted if the main contractor or another subcontractor falls behind or starts late in the programme.

Rushed lining

One unacceptable practice that is becoming more common, particularly with brick veneer cladding, is to rely on the building paper or wall wrap to keep the framing and insulation dry while finishing out the interior of the building. No current synthetic building wraps or building papers are sufficiently waterproof to keep out water. This means that if the lining, stopping and painting are completed before the cladding is installed, the end result will be detrimental wetting of framing, insulation and linings.

Rushed roofing

Subtrades often like to do their work in the minimum number of visits. Roofers, for instance, like to have all the bargeboards and fascias fitted so they can complete the roofing, ridges, barge flashings and spouting in one go. However, the risk of water entry is higher where bargeboards and fascias are fitted before the wall cladding is completed. In many instances the cladding ends up butted to the underside of the trim or cut around it. This leaves a line of potential weakness where there is no effective barrier against water entry. Ideally, any cladding immediately adjacent to a bargeboard or fascia should be installed and completed, including waterproofing, before the bargeboard or fascia is installed over the cladding. Figure 1 shows an example of an unsatisfactory detail to the top of a stucco cladding.

Work that is carried out too early or too quickly may have to be demolished or removed to allow another trade to complete their contracted work. Any subsequent repair just adds to costs and delays.

Figure 2: Correct installation of reverse-slope eaves.

Rushed soffits

Wall claddings installed after the soffit linings are fixed can lead to a higher risk of water entry at the junction, particularly on sloping soffits. Because the cladding is finished under the soffit, any water on the soffit surface may run behind the cladding through gravity or capillary action. The better solution is to install the wall cladding before any soffit lining. This allows the finished surface of the soffit to be lower than the top of the wall cladding, improving the safety of the detail in terms of keeping out the water. Where a drained and vented cavity is installed behind the cladding, a continuous top batten or blocking must be used to close off the top of the cavity from roof spaces above. (Figure 2 shows a detail for a reverseslope soffit.)

Rushed finishing

The surfaces of finished areas or materials can be damaged by other work operations, such as paint or bitumen overspray, people traffic over a finished surface, diggers operating, services access, backfilling, falling equipment or materials, and storage of materials on completed surfaces, such as roof decks. If you perform the sequence of operations on a job in a timely fashion you should end up with a high-quality job.

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Articles are correct at the time of publication but may have since become outdated.

Figure 2: Correct installation of reverse-slope eaves.

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