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Repair Methods for Rendered S tructures. Rak-43.3313 Repair Methods of Structures, exercise (4 cr) Esko Sistonen. Anon. 2005: Rendering Book 2005. Helsinki. BY 46. 158 p. (in Finnish). This kind of cracks in facade are usually a sign for uneven settling of the building foundations.
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Repair Methods for Rendered Structures Rak-43.3313 Repair Methods of Structures, exercise (4 cr) Esko Sistonen
Anon. 2005: Rendering Book 2005. Helsinki. BY 46. 158 p. (inFinnish) This kind of cracks in facade are usually a sign for uneven settling of the building foundations.
Repair methods • To do nothing • Coating and patch repair methods • Light coating repair (minor patch repairs, coatings) • Full patch and coating repair • Covering repair methods • repair of entire facade, for instance, with an • insulating rendering • Demolition and reconstruction • Rendering removal and re-rendering • Related repairs • Decreasing the level of exposure • Repairs based on damaged underlayer
Different factors which has influence on decision ofrepair method Lahdensivu, J. 2007. Selection of repair methods for rendered facades. In: Carpinteri et al. (eds.). Fracture Mechanics of Concrete and Concrete Structures. Vol. 3. High-Performance Concrete, Brick-Masonry and Environmental Aspects. Proceedings of the 6th International Conference on Fracture Mechanics of Concrete and Concrete Structures, Catania, Italy, 17-22 June 2007 pp. 1661-1666.
Selection of suitable repair alternative for each casehas several demands: • The repair must be cost effective • Aesthetic requirements • Degree of different deterioration mechanisms • Service life requirements of repair • Requirements concerning the reliability of the repair
Repairmethods of renderingdamage Anon. 1999: Rendering Book. Helsinki. BY 46. 90 p. (in Finnish)
Different removal methods for old rendering
Renderingrepair products Lime mortar Lime cementmortar Cementmortar Mortar is chosen depending on the case: -In patch repairs as same as the old -In re-rendering based on underlayer characteristics: rendering mortar layers should be weaken towards the surface, trowelled rendering should not be stronger than underlayer. Mortar additives: -air-entraining agent -retarders -polymers -fibers -seal and hydrophobic substances -pigments L (K) Lime HL (Kh) Hydrolic lime C (S) Cement LC (KS) Lime and cement e.g. LC (KS) 35/65/600
Externalwallinsulation http://en.wikipedia.org/wiki/File:EWIS.jpg
RenderedFacades: ThickRendering Thick rendered facade with slab insulation Timberframe - thickrendering-solution http://www.paroc.fi/solutions-and-products/solutions/walls/thick-rendering
RenderedFacades: ThinRendering Rendered facade with slab insulation Rendered facade with lamella insulation http://www.paroc.fi/solutions-and-products/solutions/walls/thin-rendering
RenderedFacades: ThinRendering http://www.e-weber.fi/rapatut-julkisivut/weber-tuotteet/uudisrakentamisen-julkisivuratkaisut/serpotherm-eristerappaus-hienoroiskepinnalla.html
Tree coat rendering •Mineral wool with lime- or limecement mortars •The tree coat rendering has been fasten with mechanical anchor to buildings framework. • Hot-dip galvanised welded wire mesh (f1 mm #19 mm) • Base plate etc. Thin rendering •Mineral wool or expanded polystyrene (EPS) • cement-based and usually polymer modificated mortars •Rendering is fixed to insulation with mortar and mechanical plastic fasteners. In some cases there are no mechanical anchors. • Plastic-coated glass fibre alkali-resistant reinforced mesh • Base plate etc.
Several internet links and publications… http://www.refina.co.uk/glossary_plastering.php http://www.betoniyhdistys.fi/index.php?__EVIA_WYSIWYG_FILE=2620&name=file http://www.betoniyhdistys.fi/index.php?__EVIA_WYSIWYG_FILE=2613&name=file http://www.julkisivuyhdistys.fi/julkkari2/juko/kansio.html http://www.buildingconservation.com/articles/articles.htm http://link.springer.com/content/pdf/10.1617%2Fs11527-012-9849-7 http://publications.theseus.fi/bitstream/handle/10024/26698/NoviaUASS-LimeRen978-952-5839-21-0.pdf?sequence=1 http://www.inca-ltd.org.uk/ Perander Thorborg; Råman Tuula (1985) Ancient and modern mortars in the restoration of historical buildings. VTT, Espoo. 74 p. + app. 24 p. Tiedotteita 450 / Valtion teknillinen tutkimuskeskus. Konow, von Thorborg (1989). Saltvittring i tegel – saltvittringsmekanismer. VTT, Espoo. 68 p. + app. 8 p. Tiedotteita 1003/ Valtion teknillinen tutkimuskeskus.
Several standards… SFS-EN 998-1 (September 2010). Specification for mortar for masonry - Part 1: Rendering and plastering mortar. SFS-EN 1015-12 (February 2000). Methods of test for mortar for masonry - Part 12: Determination of adhesive strength of hardened rendering and plastering mortars on substrates. SFS-EN 1015-19 (September 1998). SFS-EN 1015-19/A1 (October 2004). Methods of tests for mortar for masonry – Part 19: Determination of water vapour permeability of hardened rendering and plastering mortars. SFS-EN 1015-21 (December 2002). Methods of test for mortar for masonry - Part 21: Determination of the compatibility of one-coat rendering mortars with substrates. SFS-EN 13658-2 (May 2005). Metal lath and beads - Definitions, requirements and test methods - Part 2: External rendering.
Several standards… SFS-EN 13914-1 (March 2005). Design, preparation and application of external rendering and internal plastering - External rendering. SFS-EN 13914-2 (May 2005). Design, preparation and application of external rendering and internal plastering - Part 2: Design considerations and essential principles for internal plastering. SFS-EN 15824 (July 2009). Specifications for external renders and internal plasters based on organic binders.