Presentation on theme: "Burnley College Plastering Diploma Level 2 Internal solid plastering Internal plastering covers walls and ceilings, prior to decoration. A variety of materials."— Presentation transcript:
Burnley College Plastering Diploma Level 2 Internal solid plastering Internal plastering covers walls and ceilings, prior to decoration. A variety of materials can be used to provide a sound, flat, smooth surface for decoration. Sometimes, decoration is needed. Plastering provides sound and thermal insulation. It also improves levels of hygiene, allowing for wiping down.
Burnley College Plastering Diploma Level 2 History of plastering Plaster is at least 4,000 years old. It was used by the Egyptians (in the pyramids) and the Greeks (who produced plasterwork in 500 BC ). The Romans introduced plastering to England. Henry III admired the whiteness and fineness of gypsum (Plaster of Paris), so he brought it to England. Plasterers were formed into a guild (a company) which was granted a charter by Henry VII. Decorative ceiling and frieze
Burnley College Plastering Diploma Level 2 Examples of some tools and equipment used for internal plastering Hawk Trowel Floats Spirit level Gauging trowel Spot board and stand Floating rules Mixing equipment Internal angle trowels Other tools and equipment required Two sizes of plastering trowel
Burnley College Plastering Diploma Level 2 Preparation of background What is adhesion? What is suction and how does it improve or hinder a plasterer? Block work toothed into facing brickwork
Burnley College Plastering Diploma Level 2 Types of background 1.Normal clay bricks or blocks 2.Dense clay brickwork, blockwork, calcium silicate blocks, concrete blocks 3.Dense concrete, engineering bricks 4.Painted brickwork, glazed tiles, glazed brickwork Surface key is it good, moderate or poor Good key: if joints are raked out keyed blocks when keyed bricks are used Moderate key: flush brickwork or blockwork Poor key: flush brickwork or blockwork unless surface has been keyed in manufacture Preparation required prior to plastering Brush and damp down according to suction. Rake out soft joints in old brickwork. Test suction if poor and apply spatterdash coat. Mechanical key, hand key or spatterdash coat. Test with bonding agent (PVA).
Burnley College Plastering Diploma Level 2 Types of background in British Standard 5262 Dense, strong and smooth materials Moderately strong, porous materials Moderately weak, porous materials No fines concrete Composite backgrounds
Burnley College Plastering Diploma Level 2 Forming a key Purpose of a key Forming a mechanical key Forming a spatterdash coat Using liquid PVA or EVA for forming a key Forming a key by hacking the surface
Burnley College Plastering Diploma Level 2 Preparation checklist Brush down background to clean it. Remove mortar snots from joints, internal and external angles. Make a key (if needed) to background. Test background for suction; treat if necessary. Place drop boards at bottom of wall to catch falling materials and keep floor cleaner. Fix EML to timber wall and soleplates as necessary. Fix angle beads. Set up spot board and stand; wet in the board.
Burnley College Plastering Diploma Level 2 What is contained in a specification? Type of material Number of coats Thickness of plaster Standard of work
Burnley College Plastering Diploma Level 2 Materials used in plastering Sand Lime Cement Plaster
Burnley College Plastering Diploma Level 2 Sand Types and sources of sand What is meant by a well-graded sand? What is the purpose of sand? The effects of bulking Performing a simple site test for sand What is silt and how does it affect plastering sand? Sand contained in a sand bay with protective covering sheet
Burnley College Plastering Diploma Level 2 SymptomResultPossible causes Delayed set or total failureWeakness, shrinkage, cracking, delayed expansion Too much clay Very slow set of gauged lime mortar Delay in buildToo much clay, animal or vegetable matter (e.g. leaves) Low finished strength or mortarPoor sticking of backing coatsToo much sand; too much clay Efflorescence, dampness and rusting of metalwork Unsightly appearance, damage to brickwork Too much salt Poor workabilityPoor stickabilityBadly graded sand Rust-coloured stainingLots of expansionToo much iron impurity Blowing of plasters and rendering Bond failureClay balls or coal particles Faults with poor quality sand
Burnley College Plastering Diploma Level 2 Lime Manufacture of lime Types of lime Hydrated lime Hydraulic lime Purpose of lime in a plastering mix A lime works
Burnley College Plastering Diploma Level 2 Ordinary Portland cement Raw materials of OPC Manufacture of cement Hardening and curing of cement Other types of cement Lightweight cement-based materials
Burnley College Plastering Diploma Level 2 Plaster Chemical formula of plaster CaSO 4 2H 2 O Setting of plaster Types of plaster and their uses Storage of plaster and effects of poorly stored plaster Method of mixing different types of plaster
Burnley College Plastering Diploma Level 2 Proportioning and gauging plastering materials Method of gauging materials Traditional cement, lime, sand mixes Mixing in a trough Mixing in a bucket or drum Mixing by cement mixer Mixing by hand Mixing of lightweight plaster in a trough, using a larry/rake. Work station set up.
Burnley College Plastering Diploma Level 2 Plaster coats – method of work One-coat work Two-coat work Three-coat work Dubbing-out coat Render coat Application of lightweight plaster
Burnley College Plastering Diploma Level 2 Forming box or broad screed The purpose of screeds The method of forming screeds, horizontally and vertically Method of ruling off screeds Filling in between screeds Method of forming a key between plaster coats Ruling in a vertical screed
Burnley College Plastering Diploma Level 2 Dot and screed or plumb and dot Use of the dot and screed or plumb and dot system Method of forming dot and screed and plumb and dot systems Use of a plumb bob and gauge Plumbing in horizontal screeds Ruling in from horizontal screeds Plaster dot
Burnley College Plastering Diploma Level 2 Setting coat Method of forming a finishing coat depends on background Finishing coat should not be stronger than backing coat Purpose of a finishing coat Method of forming a finishing coat to a floated background The setting system; trowel, trowel, and trowel, float, trowel A bucket of mixed finishing plaster
Burnley College Plastering Diploma Level 2 Setting coat to a plasterboard ceiling: applying reinforcement Types of reinforcement of plasterboard joints Application of reinforcement Position of reinforcement to a ceiling
Burnley College Plastering Diploma Level 2 Plastering a ceiling or wall on plasterboard in one coat system Applying a finishing coat to a partition Applying a finishing coat to a ceiling 1 st coat lay between reinforcement 2 nd coat laid over whole ceiling Always work leaving behind finished work Trowel up leaving a finished matt surface
Burnley College Plastering Diploma Level 2 Beads (metal and plastic trims) Purpose of beads Types of beads available Method of fixing of angle beads Standards required for the fixing of beads Fixing and levelling in an angle bead
Burnley College Plastering Diploma Level 2 Forming window openings, reveals and attached piers Method of fixing beads around windows Using timber rules around window openings Forming reveals to window openings using reveal gauge Forming returns and corners to attached piers
Burnley College Plastering Diploma Level 2 Forming attached piers (1) What is an attached pier? Back wall floated flat and keyed An attached pier Looking down onto an attached pier
Burnley College Plastering Diploma Level 2 Attached and independent piers (2) Fix angle beads or timber rules plumb and straight Check at top, middle, bottom, for equal measurement on face When using angle beads check for squareness at top, middle and bottom Float and set face and returns when using beads When using rules float face, return rules onto face. Float and set returns Return rules back onto return and set face
Burnley College Plastering Diploma Level 2 Lining in attached piers Method of lining in face of pier Angle beads fixed at the two ends String through line Place a nail or piece of timber between string and nosing of two end angle beads Fix intermediate angle beads checking for plumb and straightness Check that nosing of bead does not fail on the string Lining through a row of attached piers
Burnley College Plastering Diploma Level 2 Independent piers Lay floating rule on floor thickness of floating from face of pier Mark along rule with a pencil Using building square against rule mark floor Continue around pier Place nosing of bead on intersection of lines Setting out and squaring in an independent pier
Burnley College Plastering Diploma Level 2 Floating and setting coat to a ceiling Set up a datum line Position of dots on ceiling by using the building square Positioning and ruling in screeds using dots on ceiling Float up ceiling off of screeds Form a finishing coat to ceiling Setting out of dots to a ceiling
Burnley College Plastering Diploma Level 2 Floating a beam Fix and line through beads Check squareness of side checks of beam Check measurement of soffit of beam Position of screeds and ruling in Method of finishing beam Worms eye view of a ceiling beam
Burnley College Plastering Diploma Level 2 Method of patching a ceiling Method of forming repairs to a wood lath ceiling Method of forming repairs to a plasterboard ceiling
Burnley College Plastering Diploma Level 2 Making good to a wall 1. Brush down damaged area; remove dust. 2. Rake out mortar joints to form key. 3. Remove plaster to form undercut under existing plaster. 4. Wet in background area and undercut, or coat with PVA adhesive. 5. When PVA is tacky, add plastering material to repair. 6. Rule in floating coat, then key to receive finishing coat. 7. When plaster set, cut back floating – especially around edges of repair. 8. Wet in surrounding area and add finishing coat.