From ceiling void to shadow gap — the architect's complete detailing, coordination and specification playbook for concealed internal shading in South African projects.
Most concealed-blind disputes on South African projects trace back to the same root cause: "concealed blind" was written on a drawing without a section detail behind it. This masterclass gives registered architects and design professionals a rigorous, dimensioned method to size the pocket to the rolled fabric, coordinate the ceiling against services, close the light leak, size the concealed motor, guarantee maintenance access, and write a contractor-priceable specification — for ceiling pockets, bulkheads, plaster-in details and cavity blinds across SA commercial, residential and hospitality work.
Every concealed-blind pocket resolves the same five dimensions: the clear internal width for the tube and brackets, the clear depth for the rolled-up fabric at its largest diameter, the slot width through which the fabric passes, the fascia/closing detail, and the access provision for service. Get any one wrong and the blind either jams, shows light leaks, or cannot be repaired without breaking ceiling. This lecture dissects a generic pocket against real tube sizes — the 32 mm, 38 mm and 45 mm aluminium tubes common in SA, and the rolled fabric build-up that determines minimum clear depth. We introduce the cardinal rule: size the pocket to the fully-rolled fabric diameter plus clearance, never to the empty tube. A 2 800 mm drop of dim-out fabric on a 45 mm tube can roll to 95–110 mm diameter; a 100 mm pocket that ignored this fails on installation day. We also fix the slot geometry that prevents the fabric scraping the plasterboard edge.
A concealment pocket is a small piece of three-dimensional joinery that must satisfy five dimensions at once, and the failure of any single one is visible, audible or terminal. The clear internal width must accommodate the tube plus the brackets and any motor head and idler at each end, so the pocket is always wider than the glass it serves. The clear internal depth is the dimension that defeats most first-time specifiers: it must equal the diameter of the fabric when fully rolled, not the diameter of the empty tube. This is the cardinal rule of the whole discipline. A bare 45 mm aluminium tube looks small in a 100 mm pocket, and the temptation is to call the pocket generous. But wrap a 2 800 mm drop of dim-out fabric onto that tube and the roll grows to 95-110 mm diameter; the 'generous' 100 mm pocket now jams the blind before it reaches the top, in a void that cannot be opened without cutting ceiling.
A 2 700 mm drop of 3% screen on a 45 mm tube rolls to ~80–90 mm diameter, so clear internal depth = rolled diameter + clearance = 90 + 20 = 110 mm, rounded to a buildable 120 mm. Sizing to the bare 45 mm tube would have produced a blind that jams before the top — in a void that cannot be opened without cutting ceiling.
Target audience: Registered architects, architectural technologists and interior architects (SACAP, IID) responsible for detailing and specifying concealed internal shading on South African commercial, residential and hospitality projects.
Assessment: 10 application-based multiple-choice questions, minimum pass mark 70%. Certificate of completion on passing.
Your enrolment includes the full C20 package: the in-depth eBook with worked detailing examples, the practical how-to guide with the full assessment bank, and the A4 quick-reference cheat sheet.