Limelite CPDPresentation Version 2.0, March 2013
The use of LightweightCement/Lime-based Plastersfor the renovation ofTraditionally Built Properties. Limelite CPD Presentation
Objectives To provide the audience with an understanding of: • A brief history of plaster in the UK • Problems associated with traditional Gypsum plasters • Repairing damaged gypsum plasters • The Solution - Lightweight lime-cement renovating plaster, such as Limelite Renovating Plaster • Key features of lime-cement renovating plasters • The application of Limelite Renovating Plaster • Areas of use • CPD Assessment & Certification • Considerations How to get your CPD Certificate? • Answer the questions at the end of the presentation and send them along with your contact details to email@example.com
A Brief History of Plaster - Origins • Plastering has its origins going back 4000 years to the Ancient Egyptians when it was discovered that they used gypsum plaster and canvas to encase their mummies. • The Romans came up with a hydraulic lime plaster and discovered that adding volcanic ash (Pozzuolana) they had inadvertently discovered concrete. The ash was discovered at Pozzuoli close to Naples, from which it obtained it’s name. Image: Hostas, 2010
A Brief History of Plaster - Origins • In 1212 King John of England issued a law that all remaining houses in London should be plastered following the fire on the old London Bridge. The first example of Fire Protection. • In 1665 (The Great Plague) King Charles 2nd decreed that all domestic dwellings will be plastered internally with a lime based plaster to kill the bugs Image: London Tourist, 2012
A Brief History of Plaster - The 19th Century • In 1824 Joseph Aspdin a Leeds Stone Mason developed an early version of Portland Cement replacing the use of Hydraulic Lime. • The use of a 1:1:6 blend with horse hair and timber lath became widespread Image: Ben Dalton, Leeds UK, 2010
A Brief History of Plaster - The 20th Century • The 1930’s saw the introduction of Gypsum based plasters in the UK. • Shortly after this a more modern lightweight plaster was developed replacing sand with vermiculite. • In the 1960’s Gypsum plaster was widely adopted due to quicker setting time, replacing 1:1:6.
Problems with Gypsum Plaster There are common issues when using Gypsum Plasters: • Slower drying times resulting in delayed decoration. • Salts and mould appeared on surface in older “damp” properties. • Rusting of metal work such as angle beads and conduits etc was experienced. • The hygroscopic nature of Gypsum leads to complete failure when exposed to moisture. Gypsum plaster is not vapour permeable.
Problems with Gypsum Plaster - Flood Damage Gypsum plasters offer almost no resistance to flood damage • Floodwater degrades gypsum plasters and causes delamination • Up to 1 metre above floor level is typically the worst affected area.
Problems with Gypsum Plaster - Damp In damp conditions Gypsum Plaster is susceptible to rising mould growth
Problems with Gypsum Plaster - Metal Corrosion of Angle Beads, Conduits and other Metal Work is common
Problems with Gypsum Plaster - Consequences The repercussions can be extremely costly and time consuming • Local Authorities and house owners are inundated with complaints • forcing them to change back to a cement/lime based plaster that was still traditionally site batched • But site batching creates it’s own set of problems
Site Batching There are a number of problems caused by site batching: • Multi-point responsibility for quality. • Components are liable to contamination from the site environment. • Much higher risk of wastage. • Variability in quality due to inconsistent batching and raw material selection.
Flooding • Flooding is becoming an annual occurrence in the UK
Mould Growth Mould Growth is a regular occurrence in older properties
3. Repairing Damaged Plaster with Traditional Gypsum Plasters
Repairing Damaged Plaster - Traditional Methods The Process: • Hack off the damaged plaster • Treat wall with an injected Damp Proof Course (DPC) if required • Wait for substrate to dry • it usually dries at a rate of 25mm per month. • Re-plaster when dry.
Repairing Damaged Plaster - Traditional Methods There are common problems with the traditional methods: • It can be many months before the wall is dry enough to re-plaster, leading to increased project time and customer inconvenience. • Risk of salts passing through newly applied gypsum plaster, creating efflorescence. • Gypsum will break down again if problem returns or persists. • In properties/areas liable to damp or flooding, it is simply not a long term solution
4. The Solution Cement and Lime Based Renovating Plasters
The Solution? • Sand was replaced with Expanded Perlite to create modern lightweight version of Cement/Lime plaster with Synthetic Fibres added to reduce shrinkage cracking. • A Waterproofing Agent and Salt Inhibitor were added to replace the “hit and miss” of site batching. • Lime-Cement Renovating Plaster was created A Lightweight Lime/Cement Renovating Plaster
Repairing Damaged Plaster – Cement/Lime Plaster The new process: • Hack off the damaged plaster • Treat with an injected Damp Proof Course (DPC) if required • Plaster with Lightweight Cement/Lime based Renovating Plaster. • Paint with water based emulsion.
Repairing Damaged Plaster – Cement/Lime Plaster The benefits of using a renovating plaster instead: • Earlier decoration • no long waits for the wall to dry to apply the plaster • plaster dries faster than gypsum • No repeat problems • Greatly reducing the risk of salting, efflorescence and mould growth. • A permanent solution • A plaster that can withstand recurring water ingress
5. Key Features of Cement/Lime Renovating Plasters
Cement/Lime Renovating Plaster – Key Features Breathability Lightweight Cement/Lime-based Plasters effectively control dampness passing through walls and provide a barrier against salt transfer. Being ‘breathable’ means that the plaster… • allows balanced moisture movement through the construction fabric. • allows the substrate to dry naturally.
Cement/Lime Renovating Plaster – Key Features Drying Time • Due to cement content in Lightweight Renovating Plasters, drying time is faster than with gypsum based plasters. • As a result project times are reduced.
Cement/Lime Renovating Plaster – Key Features Fibre Reinforcement • Synthetic fibres increase the cohesive characteristics of Renovating Plaster to reduce crazing & cracking
Cement/Lime Renovating Plaster – Key Features Insulating Properties • Renovating Plasters contain lightweight Perlite, which improves the insulation properties of the wall. • Thermal ConductivityK Value = 0.13 W/mºC(three times lower than gypsum)
Cement/Lime Renovating Plaster – Key Features Increased Thermal Efficiency • Warmer walls mean reduced condensation on the internal surface • Lower heating bills • Walls are warmer to the touch
Cement/Lime Renovating Plaster – Key Features Corrosion Resistance • The alkalinity of cement & lime in Renovating Plasters inhibits rusting of metal works such as angle beads, conduits, etc.
Cement/Lime Renovating Plaster – Key Features Inhibits Mould Growth • The aseptic nature of lime severelyretards mould growth. • Alkalinity of lime arrests propagation of mould spores.
6. Application of Cement/Lime Renovating Plasters
Cement/Lime Renovating Plaster – Application No new methods are required • Lightweight Cement/Lime based plasters are applied in the same way as gypsum based plasters. • Can be applied to most sound mineral substrates.
Cement/Lime Renovating Plaster – Application Brickwork • Can be applied directly onto brick walls
Cement/Lime Renovating Plaster – Application Blockwork • Apply a bonding or sealing agent to the block work first to equalise the porosity.
Cement/Lime Renovating Plaster – Application Stone Work (low suction) • Add Styrene Butadiene Rubber (SBR) to initial coat for improved adhesion on stonework.
Cement/Lime Renovating Plaster – Application Wattle, Daub and Lath
Cement/Lime Renovating Plaster – Application Replacement DPCs • Renovating Plasters can be applied to damp walls. • Ideal for application after insertion of replacement DPCs following flooding.
7. Areas of use for Cement/Lime Renovating Plasters
Cement/Lime Renovating Plaster – Areas of Use Historic and Listed Buildings
Cement/Lime Renovating Plaster – Areas of Use Barn Conversions
Cement/Lime Renovating Plaster – Areas of Use Private and Rental Housing
8. CPD Certificate Assessment for Cement/Lime Renovating Plasters
CPD Certificate Assessment - Details Please complete the following details and send them in an email to firstname.lastname@example.org along with your answers to the questions on the following slide. Upon the receipt of correct answers we will issue a CPD certificate. Full Name: Company: Job Title: Address Line 1: Line Address 2: Address Line 3: Address Line 4: Postcode: Phone: Email Address: Would you be happy to receive future information on Limelite Products?Yes/No All fields are required
CPD Certificate Assessment - Questions • Name 3 common problems associated with Gypsum based plasters • Other than faster drying times, what else makes the process of repairing damaged plaster on damp walls quicker with a Cement-Lime Renovating Plaster compared with using a Gypsum Plaster? • Name 3 key features of Cement-Lime Renovating Plaster • Cement-Lime Renovating Plaster can be applied in the same manner as traditional Gypsum based plasters… Please choose:True / False
9. Considerations for Specifiers for Cement/Lime Renovating Plasters
Considerations for Specifiers – Quality & Service The leading Lightweight Lime-Cement Renovating Plaster Limelite Renovating Plaster from Tarmac Building Products Ltd • Cementitious Expertise – Limelite Renovating Plaster is managed by Tarmac’s specialist cementitious solutions division, called Pozament. • Proven track record – system used for over 30 years. • Network of Nationwide stockists – ease of supply. • Technical support –experts at a nationally recognised company. • Consistent Quality Guaranteed – Factory-produced, pre-blended, bagged product ensures that risks associated with site batching are eliminated.
Considerations for Specifiers - Standards Limelite Renovating Plaster Certifications/Accreditations • British Board of Agrèment (BBA) Approved for use after the installation of a DPC. • Environmental Certification to BS EN ISO 14001. • Manufactured in accordance with BS EN ISO 9001:2008 certified procedures.