Contract Wallcoverings - a Preparation and Application Guide

Transcription

1 Contract Wallcoverings - a Preparation and Application Guide Introduction When hanging wallcoverings of any type, whether they are domestic or contract products, it is very important to understand a few simple preparation and application methods. The methods outlined in this guide will help to ensure a successful, problem free installation. Correctly identifying and carrying out the appropriate surface preparation is often overlooked, resulting in a poor standard of decoration. This guide will help you identify the many different types of wall surfaces you will find on site(s) and gives guidance on how to prepare them. Advice is also given on the appropriate adhesive systems and tools. Also covered are methods of application and certain installation techniques. Checklist Check materials are free from damage. Check there is enough batch numbered material before cutting and hanging. Never use material from different batches on the same wall. Make sure that the materials supplied are those which were ordered and specified. Always check each new roll for an acceptable colour match to that of material already hung. At the start of the job, cut and hang 3 drops only, inspect before proceeding. Stop hanging if you think the result may not be acceptable. Keep all roll labels until the work has been accepted. Use only adhesives recommended by the Manufacturer, following pack instructions. Surface Identification When you begin any decorating project it is important to have a close look at all the different wall surfaces onto which you will be working. Take a few minutes to walk around the job to check the condition of the walls. In most cases this will be straightforward, particularly in new builds with new plaster or drylining. However, in older buildings which are being redecorated or refurbished you are more likely to find walls which may need special attention and preparation, due to their poor condition or build-up of surface coatings. Firstly, check that the wall surfaces are dry in depth with a moisture meter, and in sound condition. If there is flaking paint, crumbling plaster or there is moisture, mould staining or salt residues, you must attend to these problems before you start to decorate. A detailed approach to all the relevant surface preparation is outlined under preparing the wall on page three. Assuming that the walls are sound and dry, you need to ascertain whether the wall surfaces are absorbent or non-absorbent. This is a critical part of the surface preparation, as identifying your surface as either absorbent or non-absorbent determines which adhesive you should use. Failure to correctly identify your surface type could lead to costly remedial works at a later stage. To assist you in determining your surface type, below are typical examples of surface types you may find on site and which category they belong to, absorbent or non-absorbent.

2 Surface Directory (a directory of surfaces you may encounter) Absorbent surfaces uncoated Typical surfaces include: Plaster Plasterboard (gypsum) Sundeala board (pin board) Supalux Glassroc F R Hardboard Chipboard Timber sheet materials Plywood MDF Absorbent surfaces coated Typical surfaces will include: Emulsion paint (matt and silk) (Note: Silk emulsion can act as a semi sealed surface, if a key does not produce sufficient absorption an Alkaline resisting primer (ARP) /sealed surface adhesive system should be used) British Gypsum Gyproc wallboard primer Crosslining Old backing papers Non-absorbent surfaces uncoated Typical surfaces will include: Glass Marble Fibreglass Laminates Ceramic tiles Existing vinyl wallcoverings Non-absorbent surfaces coated Typical surfaces will include: Oil based paints (gloss and eggshell) Alkali resisting primers British Gypsum Gyproc wallboard sealer Lafarge drywall sealer Plasterboard coatings producing a sealed surface Knauf diamond wallboard primer Metals (ferrous and non-ferrous require appropriate metal primers) Varnishes Stove enamel Portaflek Lime wash/distemper Require a coating of ARP Oil based Alkali resisting primer Cement/concrete

3 (Note: Tektura recommend complete removal of all lime wash/distemper prior to inspection of substrate) If you are in any doubt as to the type of surface you are dealing with contact the wallcovering manufacturer. Preparing the wall Absorbent surface Remove all backing papers and ensure the surface is clean, smooth, dry in depth and in sound condition. Lightweight or lighter coloured wallcoverings may require a surface of uniform colour. On a dry absorbent surface apply a good quality matt emulsion and allow to fully dry. (Tektura recommend using a pigmented primer, as matt emulsion can sometimes be unstable.) All surface contaminants such as dirt, grease, polish, water, soluble stains, felt tip pen marks, etc, should be removed by washing with a detergent solution. Rinse off with clean water and allow surface to fully dry. Efflorescence - brush down affected areas with a stiff brush to remove all the powdery salt residues and leave for 48 hours. Should the efflorescence reoccur, repeat this process until the efflorescence is remedied. Mould growth and Algae - treat affected areas with a proprietary brand fungicidal wash, used in strict accordance with pack instructions. Holes, cracks etc should be filled with good quality filler, in accordance with the pack instructions. When painting adjacent areas, avoid getting paint onto the wall to be decorated with the wallcoverings. If this has already occurred, thoroughly rub down the paint to provide a good key. Uncoated absorbent surfaces Plaster, plasterboard, timber sheet materials such as chipboard, MDF etc - where necessary carrying out the above preparation, then apply one coat of manufacturers recommended primer and allow to fully dry. Dixon Turner Primer Sealer, (or white Cover Prime to help equalise the wall colour) Murabond primer, diluted 1 part primer to 3 parts clean water (allow to fully dry) Tektura Tekfix Primer (pre-mixed) Cement render or similarly alkaline powdery surfaces should be coated with a proprietary brand oil based alkali resisting primer. Allow 48 hours to fully dry, following the relevant COSHH regulations. Then treat this surface as coated and non-absorbent. Coated absorbent surfaces Flaking paint - where flaking paint is present, ideally remove all traces of the unstable coating from the walls, this will reveal either an uncoated absorbent surface (see absorbent surfaces), or a nonabsorbent surface, then treat as appropriate. If total removal of the flaking paint is not possible, scrape back to a firm edge, apply one coat of an oil based alkali resisting primer. Allow 48 hours to fully dry, following the relevant COSHH regulations. Fill out any undulations with good quality filler and allow to dry. Rub down with an abrasive paper to produce a smooth surface, spot prime filler with the alkali resisting primer. Allow 48 hours to dry, following the relevant COSHH regulations. Treat this surface as coated nonabsorbent (see non-absorbent surfaces).

4 Matt emulsion - rub down to provide a key, apply one coat of manufacturer s recommended primer. Dixon Turner Primer Sealer (or white Cover Prime to equalise the wall colour) Murabond Primer, diluted 1:1 with clean water, allow to fully dry Tektura Tekfix Primer (pre-mixed) Multi-coats of emulsion may impair the surface porosity and affect adhesion. Carry out a meths test to determine the type and/or number of surface coatings. If in any doubt contact the wallcovering manufacturer. If an oil-based paint forms part of the previously painted system, apply one coat of a proprietary brand oil based alkali resisting primer. Allow 48 hours to fully dry, following the relevant COSHH regulations. Treat as a non-absorbent surface. Non-absorbent surface Remove all backing papers, ensure the surface is clean, smooth, dry in depth and in sound condition. Lightweight or lighter coloured wallcoverings may require a surface of uniform colour. On a dry absorbent surface apply a good quality matt emulsion and allow to fully dry. (Tektura recommend using a pigmented primer, as matt emulsion can sometimes be unstable.) All surface contaminants such as dirt, grease, polish, water soluble stains, felt tip pen marks etc, should be removed by washing with a detergent solution, rinse off with clean water and allow surface to fully dry. Efflorescence - brush down affected areas with a stiff bush to remove all the powdery salt residues and leave for 48 hours. Should the efflorescence reoccur, repeat this process until the efflorescence is remedied. Mould growth and algae - treat effected areas with a proprietary brand fungicidal wash, used in strict accordance with pack instructions. Holes, cracks etc, should be filled with good quality filler, in accordance with the pack instructions. When painting adjacent areas, avoid getting paint onto the wall to be decorated with the wallcoverings. If this has already occurred, thoroughly rubdown the paint to provide a good key. Uncoated and coated non-absorbent surfaces Metal, Formica, glass fibre, oil based paints, plasterboard coatings drywall sealers/top coat etc - rub down the surface to provide a key, metal surfaces should be prepared and primed as appropriate to the type of metal, in accordance with the metal primer instructions (please contact your paint supplier for advice on metal primers). Wallcovering Primers and Adhesives The next step is to identify the appropriate adhesive system for the surfaces you are about to decorate. FIS members Dixon Turner Wallcoverings, Muraspec and Tektura recommend the follow primers and adhesives for use with their products. Primers Dixon Turner Wallcoverings Dixon Turner Primer Sealer A PVA and acrylic based priming sealing and sizing product designed to promote adhesion to most surfaces. For priming and sizing absorbent surfaces it should be diluted in the ratio of one part Primer Sealer to two parts clean water. On non-absorbent surfaces it should be used neat.

5 Dixon Turner Cover Prime A white pigmented version of Primer Sealer and is used to ensure a uniform surface colour and avoid show-through on lighter weight and paler coloured products. It should be diluted 1:1 with clean water. Both products are fast drying, 1 2 hours in most instances. Application is with a roller or brush. Muraspec Murabond Primer (sizing agent) Muraspec recommends the use of Murabond primer as part of both the preparation process and adhesive system. Murabond primer, which is a sizing agent, forms a vital part of Muraspec s hanging advice and states that without using this product, various difficulties could be experienced during the installation of its wallcoverings. Benefits are: Aids adhesion, assists the final bond of the wallcovering. Fully compatible with all Murabond adhesives. Equalises surface porosity, reduces suction and grab. Cost saving, primer 8p-10p M², diluted adhesive = 12p-24p M². Gives slip and manoeuvrability, ideal for pattern match and butt join products. Gives adhesives Good Open Time, allows good working time on porous surfaces. Forms part of the Fire Certification Process. Tektura Tekfix Primer A PVA waterbased pre-mixed primer, formulated to regulate the porosity of substrates. Will assist the adhesion of all Tektura wallcoverings, when used with the appropriate Tekfix adhesive. Adhesives Dixon Turner Wallcoverings All Dixon Turner adhesives are pre-mixed with precisely controlled water content and all contain flame retardants and fungicides. To ensure proper performance and bond strength these adhesives should be used undiluted. Dixon Turner Light (Yellow Top) Designed to hang all paper backed vinyls to plasterboard and all good, well prepared absorbent surfaces. Preferred application is by brush or roller to the wall surface, damping the back of the wallcovering with a sponge and clean water or, alternatively, pasting the paper backing and allowing to soak. Dixon Turner Standard (Red Top) A heavier grade of adhesive and is commonly used for hanging paper backed vinyls to prepared, previously painted surfaces, hanging very heavy paper backed vinyls to all normal wall surfaces and for hanging paper backed textile wallcoverings. For paper backed vinyls application is by brush or roller to the surface, damping the back of the wallcovering with a sponge and clean water. For textile wallcoverings consult the manufacturers instructions.

6 Dixon Turner Heavy (Blue Top) A premium grade adhesive designed to be used with all weights of non woven and woven fabric backed wallcoverings. It is a PVA based adhesive engineered to ensure excellent adhesion to all normal, prepared wall surfaces. Application is by roller to the wall surface with the wallcovering being hung dry. Dixon Turner Strippable Recommended when hanging fabric backed vinyls to plasterboard. Once dry, its special formulation enables the wallcovering to be removed without causing undue damage to the paper faced board. New plasterboard does not need priming when using this product. Dixon Turner Vinyl over Vinyl adhesive Specially formulated to adhere vinyl wallcoverings (particularly fabric backed) to existing vinyls and sealed surfaces such as oil based paint, laminates, glass, marble and, with suitable anti-rust primers, to metal. It is also widely used for adhering overlapped edges of vinyl in internal angles and as a border adhesive. For further advice on any aspect of surface preparation and adhesive usage, please contact Dixon Turner s Technical department on Muraspec Murabond Adhesives (Murabond Light, Standard, Heavy, Easystrip and Sealed Surface) All are water based, high solids, low moisture content adhesives. Being a blend of starch, PVA fungicides and a fire retardant, these adhesives are specifically formulated for the full range of Muraspec wall finishes to be used in the contract market. Using cheaper alternatives, which do not have the bond strength required, may be a costly compromise. Murabond Easystrip Adhesive Water based high solids low moisture content, blend of starch, PVA and fillers. This adhesive allows the dry stripping of Fabric Backed Vinyls from absorbent plasterboards, drylining or partitions, without causing undue damage to the face of the plasterboard substrate. Murabond Sealed Surface Adhesive A very low moisture content blend of synthetic polymers, which will allow for the direct hanging of wide width wallcoverings onto a non-absorbent surface. As this adhesive has a quick drying time due to its low moisture content Murabond Sealed Surface Adhesive should only be applied one drop at a time to keep within the open time of the adhesive. For further advice on any aspect of surface preparation and adhesive usage, please contact Muraspec s Technical department on Tektura Tekfix / Tekfix 65 A light weight PVA water based adhesive with added mould growth inhibitor, this adhesive is formulated to be used in conjunction with Tekfix Primer. This system satisfies BS476 parts 6 & 7 fire

7 certification requirements. Decoupage wallcoverings. Must not be diluted. Recommended for use with all Tektura paper back vinyl, Moment and Tekfix Plus A heavy weight PVA water based adhesive with added mould growth inhibitor, this adhesive can be used in conjunction with Tekfix Primer. This system satisfies BS476 parts 6 & 7 fire certification requirements. Recommended for use with both Tektura fabric and non-woven backed wallcoverings. Must not be diluted. Tekfix Strippable A PVA water based strippable adhesive with added mould growth inhibitor. Contains a stripping agent which allows the complete removal of fabric backed wallcoverings without damaging the substrates such as plasterboard/drylining and partitioning systems. Tekfix VOV A high solids acrylic based adhesive, formulated for the installation of wallcoverings over all sealed surfaces. Can be used in conjunction with ARP (alkali-resistant primer). For further advice on any aspect of surface preparation and adhesive usage, please contact Tektura s Technical department on Fire Regulations and COSHH Not using the appropriate adhesive may not only lead to adhesion problems, but could also negate any relevant fire certification. Dixon Turner Wallcoverings All Dixon Turner wallcoverings are subjected to continuous testing to ensure conformity to the latest requirements. All are Class 0 in accordance with the Building Regulations. Additionally, all new testing includes Euro Class B. Testing is normally carried out on plasterboard substrates but arrangements can be made to test on any substrate to customer requirements. Muraspec The full range of Muraspec wallcoverings have fire certification to BS 476 parts 6 and 7. The majority of Muraspec wallcoverings also have Euro Class B. All wallcoverings are tested and approved in conjunction with Murabond primer and the appropriate Murabond adhesives (Product Data Sheet and Fire Certificates are available on request). Tektura All Tektura vinyl wallcoverings conform to BS476 parts 6 and 7 and are tested in conjunction with Tekfix adhesives and primer. COSHH sheets and technical data are available on request for all products. Application (hanging) Arrange product into roll or box sequence (if numbered) always use in descending roll order eg rolls 65, 64, 63 etc. Take time to read the manufacturers hanging instructions. The majority of contract vinyl wallcoverings need to be hung reversing alternate lengths. A few need to be straight hung,

8 particularly if there is a pattern match, and there should be an instruction to this effect in the roll or box. In case of doubt always ask the supplier before starting work. Wherever possible, use cut or part rolls in isolation. Handle all wallcoverings with care to avoid damaging edges, especially materials that are butt jointed. Number the top of each drop using a soft lead pencil. Hang the drops in numbered sequence around the room ensuring the product is reversed or not as appropriate. Check for shading as you proceed. Never assume shading is caused by moisture and that it will disappear on drying. It may be a fault that needs investigation. It is not normally recommended to hang contract vinyl wallcoverings over lining paper. If lining is specified then specialist advice must be sought from the wallcovering supplier as to the correct adhesive to be used to hang it, and best method of joining the wallcovering to avoid bubbling and the lifting and opening of joints. Use only full width material. Cutting narrow widths above doors/window frames etc should be avoided. Do not infill with off cuts or out of sequence product and never join middle to edge of wallcoverings. Overlap and trim material by a consistent and minimum 5cm (2 ). Trim straight through the centre of the overlap without removing the blade from the cut from ceiling to skirting and ensuring the cut is vertical. This should be done in accordance with the specific product instructions, using the appropriate tools in order not to damage or score the substrate. Appropriate tools for paper backed wallcoverings are snap off bladed knives using a new blade section for every cut, and, where necessary, plastic surface protection strips. For fabric backed wallcoverings use a footed overlap and cut tool especially for soft or painted substrates and plasterboard. The foot ensures that the blade does not penetrate the wall or board surface as would happen with a normal knife. Wallcoverings need to settle for a minimum of 15 minutes before they are trimmed at the tops and bottoms of the drops. The ceiling and skirting edges should be trimmed using a sharp knife in conjunction with a steel or plastic spatula. When applying contract vinyl wallcoverings to the surface use only a hard plastic spatula to remove air bubbles and ensure that the wallcovering is in contact with the wall surface. This should be done in an up and down direction to avoid stretching the wallcovering. Do not traverse across the drops as this can cause uneven stretching at the edges of the drops, which in turn will affect the quality of the joint. Care must be taken not to overwork joints if a seam roller is used. Vinyls - use a soft foam roller. Textiles - use a hard seam roller in conjunction with a clean piece of waste material placed face to face on the wallcovering. Internal corners are best cut using a plastic spatula and sharp knife allowing a return of 2mm around the corner. This is usually the depth of the spatula. Overlap and cut joins should be done at least 15cm (6 ) away from a corner. To ensure its complete removal, excess adhesive must be cleaned away whilst still wet using a clean sponge and water.

9 Wallcovering Terminology Batch A quantity of wallcovering made at one time from the same base materials. Fabric backed vinyl Fabric backed vinyl is recognisably the most practical of wallcoverings for use in commercial interiors, deriving its strength from a vinyl surface reinforced with either a woven cotton scrim or non-woven polyester backing. Fabric backed vinyls have excellent impact and abrasion resistance and can be scrubbed clean. Understandably, fabric backed vinyl is widely specified. Particularly for high traffic areas such as busy offices, corridors, lift lobbies and receptions, where its durable nature ensures a smart appearance for many years. At 130cm or more wide, it is ideal for covering partitioning panels without the need for joints. Fabric backed vinyl is the best solution for clients who are looking for important long-term cost benefits in their buildings because it is longer-lasting, easily maintained and needs replacing less often. Overlap and Trim Joint Splice Double Cut Where wallcoverings are not factory trimmed at the edge, it is recommended they be overlapped at the edges of the wallcoverings by a minimum of 5cm/2 inches. Cut through the centre of the overlap, remove selvedge and make the joint. Manufacturers recommend specific tools to carry out this procedure to avoid damaging the substrate. BS symbol for this is: Reverse Hang This is where alternate drops are hung upside down to previous drops. This counteracts any slight shade variances across the width of the product. BS symbol for this is: Roll and Drop Sequence Most contract wallcoverings are made in large batches. Because of manufacturing tolerances, subtle colour variance can be experienced from the beginning of the batch to that of the middle and end of the batch. Therefore, manufacturers will number each roll and recommend the materials are hung in roll sequence and drop sequence. This minimises the risk of shading when changing rolls. Roll Labels Supplied fixed to the wallcovering and contains important product information like name, design, colourway, batch number. The roll label will also contain the number required to maintain the sequential hang of the product. Roll labels are best kept until work has been accepted. Straight Hang All drops are hung in the same direction from the roll. BS symbol for this is:

10 Textile wallcovering Textile wallcoverings have traditionally been used to imply quality and prestige. In doing exactly this, textiles not only create environments that are distinctly different from the everyday, but many also offer sound-deadening qualities increasing their use in a wider number of commercial situations. Widths vary. Obtaining the best results with textiles does require extra care and attention and this should be considered when specifying, in tendering, and in the actual application of textile wallcoverings. Three Drops This is recommended because most contract materials are generally reverse hung. By hanging three drops you see both edges of the centre drop abutted to subsequent drops. Any problems which may have occurred become apparent. Wide width paper backed vinyl The wide width paper backed vinyls are especially suitable for use in partitioning systems. Not as durable as the FBVs, they are nonetheless manufactured to superior contract standard and offer good value for money. 130cm or more wide, they have the advantage over narrow width products of faster wall coverage with fewer joins and are thus economical to apply. Acknowledgment: This information is based on Muraspec s leaflet A Preparation and Application Guide. The FIS gratefully acknowledges the assistance of Dixon Turner Wallcoverings, Muraspec and Tektura in the preparation of this information sheet.