Construction Methods, Materials and Detailing
What you must know
This domain tests whether you can draw a junction that can actually be built and will perform. Understand the main structural systems (strip and pad footings, slab-on-ground, suspended slabs, timber and steel framing, loadbearing masonry) and the envelope systems that enclose them: cavity brick veneer, rendered foam or lightweight cladding, curtain wall, and roofing in tile, metal sheet, or membrane. Detailing knowledge centres on the sequence of layers - structure, sheathing, sarking or waterproofing, insulation, cavity, cladding - and on continuity of those layers at corners, openings, parapets, and penetrations. Water management is the recurring theme: falls to drains, weep holes, flashings, damp-proof courses, sill trims, and the difference between a drained and a sealed joint. Material properties such as thermal movement, moisture movement, and fixing compatibility drive many details.
Traps
Questions often present a detail with one layer in the wrong order - insulation outside the waterproofing, or a flashing that laps the wrong way. Remember that water must always be directed outward and downward, so upper flashings lap over lower ones. Another trap is confusing a damp-proof course (horizontal, rising moisture) with a damp-proof membrane (under slab), or specifying a fixing that is incompatible with the substrate. Watch for nominal versus actual timber sizes.
Worked example / rule of thumb
At a window head in a cavity wall, the sequence from outside is: cladding, cavity, flashing turned up behind the cladding and dressed over the frame head, then the frame and internal lining. Rule of thumb: draw the water path first, then fit the materials around it. If a proposed detail traps water at any point, it is wrong regardless of how neat it looks.