Lesson 1Compatibility and galvanic corrosion: avoiding dissimilar metals and recommended separation methodsThis section explains compatibility and galvanic corrosion for metal roofs in Namibia. It shows how to dodge bad metal mixes, pick safe fasteners, and use separation layers, drainage, and detailing to safeguard zinc and zinc-coated steel parts.
Galvanic series and risk rankingProblematic metal combinationsNonmetallic separation layersFastener and accessory selectionDetailing to keep joints well drainedLesson 2Fasteners and clip systems: concealed clips, exposed screws, recommended materials and corrosion considerationsThis section covers fasteners and clip systems for metal roofing here in Namibia. It explains concealed clips, exposed screws, material choices, pull-out strength, and corrosion risks, with tips on spacing, torque, and sealing washers for zinc roofs.
Concealed clip types and layoutExposed screw selection and sizingStainless vs coated carbon steelFastener spacing and edge distancesAvoiding overdriving and oil canningLesson 3Roof deck and substrate requirements: steel purlins, timber battens, sheathing compatibilityThis section explains how roof decks and substrates need to hold up metal roofing properly. It covers steel purlins, timber battens, and sheathing, stressing spacing, stiffness, fixings, and matching with zinc and zinc-coated steel panels.
Minimum deck slopes for metal roofingSteel purlin sizing and spacing rulesTimber batten dimensions and fixingSheathing types and fastener pull-outSubstrate flatness and tolerance checksLesson 4Standing seam vs corrugated vs ribbed profiles: water tightness and thermal movementThis section compares standing seam, corrugated, and ribbed profiles for Namibian roofs. It looks at water tightness, wind resistance, and thermal movement, helping you select profiles, seam heights, and fixings for slope, exposure, and zinc materials.
Profile selection by roof slopeStanding seam height and lock typesCorrugated and ribbed span limitsWater channeling and side lap designThermal movement in long panelsLesson 5Accessory materials: flashings, ridge caps, eaves trims, sealants compatible with zinc/zinc-coated steelThis section details accessory materials to finish off metal roofs nicely. It covers flashings, ridge caps, eaves trims, and sealants, focusing on watertight design, thermal movement, and chemical matching with zinc and zinc-coated steel.
Types of flashings for zinc roofsDesigning ridge and hip capsEaves trims and drip edge detailingSealant types safe for zinc surfacesThermal movement joints in accessoriesLesson 6Comparison of zinc vs zinc-coated steel: corrosion resistance, patina formation, lifespanThis section compares zinc and zinc-coated steel for roofing in Namibia. It checks corrosion resistance, patina formation, stiffness, cost, and lifespan, helping you choose the best metal for local climate, detailing, and upkeep needs.
Base metal composition differencesPatina formation stages on zincCorrosion behavior in marine zonesCost, weight, and stiffness trade-offsTypical lifespan and warrantiesLesson 7Material properties: thickness (mm/gauge), coating weights, and expected durabilityThis section reviews key material properties for metal roofing suited to Namibia. It covers thickness in mm and gauge, coating weights, hardness, and durability, linking these to spanning ability, dent resistance, and service life.
Common zinc and steel thicknessesGauge systems and metric conversionCoating weight classes and labelsMechanical strength and span limitsService life expectations by climateLesson 8Insulation and ventilation strategy: types of insulation (rigid, mineral wool), ventilation gaps and placementThis section explains insulation and ventilation plans under metal roofs for Namibian weather. It covers rigid boards, mineral wool, ventilation gaps, and vent placement to handle condensation, boost comfort, and protect zinc systems.
Choosing rigid vs mineral woolWarm roof vs cold roof build-upsVentilation gap sizing and layoutEave and ridge vent positioningCondensation risk assessment basicsLesson 9Typical panel widths, lengths, and recommended overlaps for zinc and galvanized steelThis section sets out typical panel widths, lengths, and overlaps for zinc and galvanized steel in Namibia. It tackles coil widths, expansion limits, side and end laps, and handling to keep installs watertight, cost-effective, and stable.
Standard coil and panel widthsMaximum practical panel lengthsSide lap geometry and sealant useEnd lap lengths and staggeringTransport and site handling limitsLesson 10Underlayment options: breathable membranes, vapor barriers, and synthetic underlays for temperate climatesThis section presents underlayment choices for metal roofs in Namibia's temperate zones. It compares breathable membranes, vapor barriers, and synthetic underlays, explaining placement, lapping, and flashing integration for safe moisture control.
Breathable membrane functionsVapor barrier placement rulesSynthetic underlay performanceUnderlay laps, tapes, and sealingIntegrating underlay with flashings
