2 NATIONAL CURRICULUM STATEMENT Grade 10 – Drawing basic floor plans of dwellings incorporating scale and dimensioning techniques.Grade 11 – Drawing single-level dwellings including foundation to ceiling using appropriate sections, scale and dimensioning techniques.Grade 12 – Drawing all aspects of single-level dwellings including foundation to roof, electrical wiring diagrams and plumbing using appropriate sections, scale and dimensioning techniques.
3 Foundation to floor slab Foundation to ceiling Foundation to roof ContentGrade 10Grade 11Grade 12Floor planElevationsSectional elevationFoundation to floor slabFoundation to ceilingFoundation to roofSite plan & schedule of spec’s
4 GRADE 10 Brick and Block sizes Wall types Foundation DPC – Floor DPC - WallFloor slabFloor planElevationsFixtures
5 GRADE 11 Windows Doors DPC (Doors & Windows) Section of walls Detailed Elevations
6 GRADE 12 Roof / Trusses Eaves (Open – Close) Site plan Plumbing DrainageWiringSchedule of specifications
11 WallsWalls are divided into different categories according to the purpose of the wall. Seeing as we only expect the pupils to design a one storey house the two most important walls can be divided into the following:a) load bearing walls and b) non loading bearing walls.a) Load bearing walls has a thickness of at least 220mm and mostly used for the shell of the house. These walls will usually carry the weight of the roof. There are two types of walls in this category namely, one brick walls and cavity walls. Cavity walls are mostly used along the coastal areas of the country or where there is high rainfall. The one brick wall is mostly used in drier areas like the interior of the country. The cavity is never less than 50mm and must be free of any cement.b) Non load bearing walls are usually used for the inside of the house to divide the house into rooms. They are also called half brick walls (110mm).
12 WallsTo strengthen walls we use welded wire mesh (brick force) and wall ties (see drawing). There must be at least 3 wall ties in every square meter of wall. Wire mesh is mostly used to strengthen the wall above doors and windows. The norm is to place wire mesh in between at least two courses above openings. These wall ties and wire mesh must be coated with a anti-rust coating (galvanized or plastic coating).There are two methods of drawing a wall when it is sectioned. The one method is used when the scale of the drawing is 1:20. In this instance we will indicate the individual bricks. When the scale of the drawing is smaller than 1:20 we will indicate the wall only as outlines.
14 FoundationsFoundations must always be in solid ground. The foundation is one of the most important parts of the building. The following guidelines are given:1. Foundations may not be thinner than 200mm.2. Foundations for half brick (110mm), non load bearing walls may be 400 x 200mm.3. One brick (222mm), load bearing wall may be a min size of 600 x 200mm.4. Cavity (270mm), load bearing wall may be a min size of 730 x 230mm.5. Foundations must be at least 150mm below the natural ground level (NGL)Foundations are also influenced by the soil structure (sandy, clay & rock).
15 FoundationsThe floor of a house must be done on at least 150mm of compacted hardcore. Hardcore is defined as sand and small stones that will compact to a firm surface. Plant material and bricks must be removed when preparing the ground for compacting.To prevent moisture and water from seeping through the floor a SANS approved damp proof course (DPC) must be placed below the concrete floor.Before laying the concrete floor (slab), the cavity in a cavity wall must be filled with a weak mixture of concrete.The top level of the floor must be at least 250mm above the natural ground level. Take note of where the dpc is placed in the wall above the floor.
18 Dimensions and areas of rooms Minimum area 6 m².Minimum linear dimension 2,1 m between walls. Habitable room.Height of ceiling. Minimum 2,4 m.Passages and bathrooms. Minimum ceiling height 2,1 m.Minimum floor area of a house 30 m².Lintel height of windows and doors 2,1 m
23 WindowsWindows provide light and fresh area to enter a room. There must always be cross ventilation in a room. The only door and window in a room is not allowed to be in the same wall.Windows are usually placed in such a way that the top of the window and the top of the door is at the same level.Take note of how dpc is placed around the window to prevent water from entering the house.
24 Ventilation and illumination Any room must have a window.Window size Min 10% of floor area 5% opening including door.Must have cross ventilation.
39 ROOFThe last two courses, below the roof truss, in a cavity wall are closed up to strengthen the wall. A 4mm galvanized wire is used to tie down the roof onto the wall plate. This galvanized wire is build into the wall between three and six courses below the wall plate. The wall plate is a piece of wood (114 x 38) placed on the last course of the inside wall. The tie beam of the roof truss rests on this wall plate.The spacing of the roof trusses depends on the roofing material that will be used. The following is a guideline for the spacing of trusses.
40 ROOF Trusses – (see resource pack) Slope Min 15°- max 30° Class A & C (A = Fibre cement. B = Metal plates).Slope Min 17°- max 35° Class B = Concrete tiles.Spacing of trusses: 760mm concrete tiles; 1400mm Metal platesMin pitchSheeting material 5° - 22°Concrete & Clay tiles 17.5° (with underlay)
41 ROOFTake note of how the roof truss is secured to the wall in the drawing provided. It is good practice to always place dpc below the battens on the roof truss. The drawings of the construction of roof trusses explain how to draw the different roof trusses. You will note that the tie beam and the rafter are always divided into equal parts. This is only a few of the roof trusses that are available on the market.Unplaned wood is indicated with two lines drawn diagonally from one corner to the other. Planed wood (PAR) is indicated by drawing freehand annual rings on the wood.
45 SEWERAGEThe drainage of a building must always be indicated on the site plan. All the roding eyes (RE) and the inspection eyes (IE) must be shown. A drainage pipe must have a roding eye every 25m. The fall of a drainage pipe must be a minimum of one meter for every sixty meters of pipe (1:60).Plumbing must be shown on the elevations.
46 ELECTRICALOn the plan view the positioning of lights, plugs and switches are indicated.The position of the main board and the distribution board are also shown in the plan view.
47 Schedule of specifications The schedule of specifications is where the draftsman will describe the different materials that will be used in the building proses, eg. Roof type, spacing of trusses, windows to be used, guttering, facias, ect.The schedule of specifications is usually printed to the side of the drawing page in a specially demarcated block.The name and contact detail of the draftsman must also be printed at the bottom of this block.The name of the owner of the property must also be printed.The street address and plot number of the proposed new dwelling must also be printed on the drawing.Some municipalities also wants the plot numbers of the neighboring plots to be printed on the site plan.
48 Plan layout Floor plan – Drawn to a scale of 1:100 or 1:50. The following information should be drawn on a house plan:Floor plan – Drawn to a scale of 1:100 or 1:50.Outside and inside walls.Door and window openings.Fixed furniture such as sanitation, washing troughs, cupboards etc.All dimensions of rooms as well as the overall measurement of the building.Room descriptions.Electrical distribution.Floor levels.Layout of rooms such as kitchens and bathrooms as well as the positions of wardrobes.
49 Sectioning drawing Foundation and floor levels. Height of walls and position of damp course (DPC).Roof truss construction and coverage detail.Natural ground level.Ceiling height.Door and window heights.
50 Elevations North-; West-; East-; and South elevations Outside finishing detail of wallsAll window and door openingsGutter and down pipe detailPlumbing detail
51 Site Plan Stand size, borders and dimensions. Stand number and adjoining stands.Servitudes and building lines.Vehicle entrance position.Sewer connection point and position of sewer line.Scale.Arrow to indicate position of true north.
52 General information Name of Client. Name of architect or draftsman. Information about the area of the dwelling as well as the coverage area on the stand.Electrical distribution symbol explanation. Street name, stand number, township name etc.