A03: Studio Journal Week 9 James Bashford 639569
Detail Drawing 1 â€“ Eave and Gutter Section (Queenâ€™s College Extension)
This detail uses some materials that are very low cost, namely the plywood and battens, minimising economic impact. The colorbond sheeting and flashing may be more expensive, particularly to install as they are so detailed and it is important to be done right to ensure it is waterproof.
WATERPROOFING Given that one of the main purposes of this detail is to waterproof the building, it is very important for it to be waterproof itself. The top face of the eave is slanted down towards the edge so that water drains away from the building into the gutter, which then leads to downpipes ensuring the water is drained properly away from the structure. Smaller details are also important, particularly to stop water penetrating the eave itself. Where the colorbond sheet meets the edge, flashing is required which overlaps the different elements of the eave. The flashing also slants up under the colorbond sheet, using gravity to prevent water from going back up and under it. Where it wraps around the edge, it then turns back up to create a drip line. Any water that reaches this point will be forced to drip back down by gravity. A second drip line is located on the soffit, preventing water from moving laterally back to the wall of the building.
Detail Drawing 2 â€“ Glass Block Window Section (Queenâ€™s College Extension) WATERPROOFING: Similar to the previous detail, a drip line is used here to try to prevent water from moving back laterally towards the building. Any water which comes down the precast panel may move back along the underside towards the window. However, it would be caught at the drip line and gravity would force it to drop. Water would then hit the bottom sill, which has been bevelled back to the edge of the window. This means that any water will flow down and off the sill and will prevent pooling at the base of the window. One thing the detail lacks, however, is flashing. Many brick veneer walls would include flashing beneath the sill, however this isnâ€™t similarly possible with precast concrete. Nonetheless, should any water make it into the void behind the window, there is no backup to drain it away.
The economic implications of this detail would be relatively minor as simple, prefabricated, low cost materials have been selected. The glass block comes encased in a steel frame and simply needs to be placed into the gap in the precast panel. As for the interior, mass produced readily available materials are used such as timber, plasterboard and a steel frame, keeping costs low.