Wykamol LGM - Liquid Gas Membrane

Preparation:

All surfaces should be clean, free from dust, debris and loose material, oil, paint, fungal growth, etc.

Non-structural cracks, less than 0.5mm must be filled. Structural cracks must be first repaired and filled. The substrate must be sound and ideally present a smooth face. Fill holes and re-point flush to the finish using Wykamol Universal mortar to suit. Old repairs must be inspected and repaired if necessary.

New laid concrete should have a clean textured surface. Internal angles should have a 45° fillet, use Wykamol Universal mortar where required.

All construction joints, including/or day joints, angle joints, movement and expansion joints, use the Wykamol Proflex Tape System.

The background surface should be smooth or have a light even texture. Any masonry should be flush pointed and defects in existing surfaces made good.

The surface needs to be clean, sound and free from dust, loose material or free surface water. The membrane should not be applied in wet conditions or where these conditions are likely to occur before the membrane has dried. The membrane should not be applied when the temperature of the background, or the air temperature, is below 7°C.

It is sometimes recommended to pre-wet concrete or masonry backgrounds, so that surfaces are damp but free from any water glistening on the surface, to aid wetting out of the background.

Because of the wide variety of background types and site conditions it is always advisable to check adhesion to the background by testing on a sample area before starting any job.

Application Method:

Wykamol LGM may be applied by brush, roller or airless spray. If necessary, the compound can be diluted with up to 10% water, however care should be taken to ensure that the correct dry coat thickness is applied. The thickness of the dried membrane per coat depends on the method of application. For a single dry coat thickness of more than 0.30mm it is recommended that the membrane be applied by airless spray. If airless spray is used single dry coat thickness of up to 1.0mm can be obtained.

Note: A single coat of 0.60mm dry thickness or more will require a greater drying time than for an equivalent multi-coat application.)

If two coats are being applied it is recommended that the coats be applied at right angles to each other.

Before applying the second coat it is necessary to let the first coat become touch dry. The time required to reach this tough dry condition will vary according to site conditions but will typically be in the order of 1 hour. It is preferable if the second coat is applied within 24 hours of applying the first coat. After all coats have been applied the membrane should be left for at least 4 days before attempting any ponding tests. Under unfavourable drying conditions this period may need to be extended.

Whilst most applications to concrete roofs have been successful, blistering (shortly after application of the membrane to the roof) has occasionally occurred. This blistering is caused by the heat from the sun causing a vapour pressure build up below the membrane. The problem is exacerbated if the background concrete is wet. The risk of blistering can be minimised by ensuring a very good bond to the background and avoiding application of the membrane in, or shortly prior to, strong sunlight. Techniques for maximising bond are:

• Vigorously brushing the first coat into the background concrete using a stiff bristled broom.

• Prime the roof with a slurry of screeding latex and cement. Allow this slurry to harden for 2 days before applying the membrane.

Construction joints: In some situations, e.g. at high stress points such as wall/floor junctions, construction, movement or expansion joints, the Wykamol Proflex Tape System should be used.

Appearance:

The colour of the liquid compound will differ slightly from the colour of the dried membrane. The colour shade may vary from batch to batch.

The product, as supplied, is a viscous liquid of similar consistency to thick emulsion paint. The membrane dries to form a tough semi-gloss finish.

Coverage:

Wykamol LGM may be applied by brush, roller or airless spray. A minimum dry coated thickness of 1.0 mm is needed to provide a gas barrier. To achieve 1.0 mm thickness, a total of 2 kg/ m² is required, therefore a 15 kg tub will cover an area of 7.5 m²

Adhesion Compatibilities:

General

Many wet applied cementitious materials bond well to the dried Wykamol LGM, particularly if they contain polymers. When applying polymer free materials such as screed, render or plaster the highest adhesion results are obtained if the material is applied as soon as the LGM is tough dry.

Alternatively, the surface of the undried LGM can be blinded with clean sharp sand or kiln dried sand to provide some mechanical key to the subsequent coating.

Bonding agents and BS8204. Part3

In order to be classified as a bonding agent, regarding clause 5.1.2 of BS8204 Part 3 1993 “Code of Practice for Polymer Modified Wearing Surfaces”, it is necessary for the slant shear strength to be above 20 N/mm² after 28 days and for the pull-off strength to be above 2 N/mm² after 14 days. Test results on LGM are 33 N/mm2 for slant shear (1 hour drying time for final coat of LGM, before compacting the mortar onto it.), and 1.3 – 2.1 N/mm² for the pull-off strength.

The values achieved depend to a large extent on the strength and adsorption characteristics of the background concrete. By priming the background with a slurry of screeding latex and cement bond strength above 2.0N/mm² are more readily achievable.

Ceramic Tile Adhesives

Most single pack ceramic tile adhesives bond well to the dried LGM coating, even after a drying period of several months. However, the longer the drying period the more opportunity there is for surface contamination.

Tile adhesives that have been designed to comply with the draft European Standard for tile adhesives can be expected to have a bond strength (pull-off) to the LGM of at least 0.5N/mm².

Floor Screed and Renders

A floor screed/render modified with screeding latex bonds well to the dried film of LGM e.g. after allowing the LGM to dry for 8 days, applying the floor screed and allowing to cure for 9 days, a pull-off value of 2N/mm² was achieved.

When using unmodified floor screeds/renders, enhanced bond values can be obtained by coating the dried LGM with a primer system.

Gypsum Plasters

The membrane complies with the bond strength requirements of BS5270 Part 1 1989 regarding bonding agents for use with gypsum building plasters.

Flooring Adhesives

Most flooring adhesives bond well to the membrane. When bonding flooring materials such as PVC sheet over the membrane two points should be considered.

• It is advisable to use adhesive/floor-covering combinations that are low in plasticiser content.
  
  

• The concrete below the membrane should be sufficiently dry, before the membrane is applied, to pass a humidity box test of the type specified in BS8203 Part 2, but with a maximum relative humidity limit of 90%

1. Typical mechanical properties on film aged at 23˚C/50% RH:
   Tensile strength at break = 4 N/mm²
   Elongation at break = 350%
   (Test speed at 500mm/min)
   
   
2. Film Hardness:
   Shore A hardness value of 70 was measured.
   
   
3. Barrier Properties:
   The following data were obtained from measurements of 0.6mm thick films (dried and conditioned in air for 7 days at about 23˚C and 50% RH).
   
   a) Resistance to water penetration (positive head pressure).
   A 0.6mm thick dry film of the membrane, supported on a porous tile biscuit, prevented water at 0.2N/mm² pressure from penetrating into the tile during the 24 hrs test period. This pressure is equivalent to a 20-metre head of water. When using the membrane on the interior of basements, the membrane should be overcoated with render, in order to prevent any hydrostatic pressure causing localised bond failure of the membrane to the background.
   
   B) Water vapour permeability (BS 3177)
   Water vapour permeability is <4g/m²/24 hours at 25C/75% RH (using Payne cups, 0.6mm dry film thickness)
   
   C) Methane permeability (RAPRA Test)
   A value of 79 mL/m²/day under a partial pressure differential of 1 bar was achieved (a comparison of the membrane data to that of low-density polyethylene film of a similar thickness indicated that the membrane is 10 times more resistance to the transmission of methane).
   
   D) Radon Test Data 
   Subject Of The Test: Wykamol M400 –based latex membrane
   Testing Procedure: Determination of the radon diffusion coefficient
   Test Regulation: ISO/TS 11665-13, method A
   Test Execution Date: 25.11.2020 – 7.12.2020
   Test Execution Place: laboratory OL124 – D2044d 

Q) What is Wykamol LGM and what are its primary uses?

A) Wykamol LGM is a high-performance Liquid Gas Membrane formulated from Styrene Butadiene Latex. It serves as an effective solution for waterproofing, gas proofing, damp proofing, and vapour proofing in various construction settings. The product is designed for application on both vertical and horizontal surfaces, providing a durable and flexible barrier against environmental challenges such as moisture, gases, and chemical substances.

Q) How is Wykamol LGM applied to construction surfaces?

A) Wykamol LGM can be applied using a brush, roller, or airless spray, depending on the specific requirements and scale of the project. For areas requiring thicker applications, airless spraying is recommended to achieve a uniform layer. The membrane is touch dry within an hour under typical conditions, which aids in quicker project completion.

Q) Can Wykamol LGM be applied to damp surfaces?

A) Yes, one of the notable features of Wykamol LGM is its ability to adhere well to damp surfaces. This property makes it particularly useful in scenarios where construction timelines are tight or where environmental conditions prevent surfaces from being completely dry.

Q) What types of gases does Wykamol LGM protect against?

A) Wykamol LGM is specifically formulated to provide protection against harmful gases like radon and methane, which are common concerns in both residential and commercial buildings. The barrier created by the membrane significantly reduces the permeation of these gases, enhancing indoor air quality and safety.

Q) Is Wykamol LGM environmentally friendly?

A) Yes, Wykamol LGM is an environmentally safe product. It is free from toxic chemicals, hazardous substances, solvents, and plasticisers, making it a suitable choice for use in environments sensitive to ecological impact and human health.

Q) What are the drying time and curing process for Wykamol LGM?

A) Wykamol LGM typically becomes touch dry within an hour, although full curing may take longer depending on environmental conditions such as temperature and humidity. It is essential that the membrane is completely cured before being subjected to any water or gas exposure.

Q) How does Wykamol LGM handle joint and crack bridging?

A) Due to its high flexibility and extensibility, Wykamol LGM excels in bridging over non-structural cracks and joints without losing its integrity. This capacity helps maintain the continuity of the membrane's barrier properties across the construction surface.

Q) Can Wykamol LGM be used for external applications like roofs and walls?

A) Absolutely, Wykamol LGM is suitable for both internal and external applications, including roofs and walls. Its robust composition ensures it withstands weather elements effectively, making it an excellent choice for outdoor waterproofing and gas proofing.

Q) What substrates is Wykamol LGM compatible with?

A) Wykamol LGM adheres well to a variety of substrates such as concrete, masonry, wood and some metals. It is also alkali-resistant, which enables application on alkaline surfaces commonly found in construction materials like concrete.

Q) Are there any special preparations needed before applying Wykamol LGM?

A) The surface to be treated must be clean, free from dust, debris, oil, and any other contaminants that might impair adhesion. It is also advisable to fill any significant cracks or voids to ensure a smooth and uniform application of the membrane.

Q) What is the recommended thickness for Wykamol LGM application?

A) For effective gas barrier properties, a minimum dry coat thickness of 1.0 mm is recommended. This thickness may vary based on the specific requirements of the project and the method of application.

Q) How does temperature affect the application of Wykamol LGM?

A) Wykamol LGM should not be applied when temperatures are below 7°C, as lower temperatures can affect the curing process and adhesion quality. Optimal application conditions would be at or above this temperature threshold.

Q) Can Wykamol LGM be painted or coated over?

A) Yes, once fully cured, Wykamol LGM can be overcoated with compatible paints or other coatings for aesthetic finishing or additional protective layers.

Q) Is Wykamol LGM resistant to chemicals?

A) Yes, Wykamol LGM is resistant to a range of chemicals, including silage acids, which makes it suitable for agricultural storage applications as well as in industrial settings where chemical exposure might be a concern.

Q) What maintenance does Wykamol LGM require?

A) Wykamol LGM is relatively low maintenance; however, regular inspections should be conducted to ensure the integrity of the membrane, particularly in high-stress areas or environments with aggressive exposure conditions.

Q) How does Wykamol LGM contribute to building safety?

A) By providing a robust barrier against water, damp, and hazardous gases, Wykamol LGM significantly enhances the structural integrity and safety of buildings. This protection helps prevent mould growth and structural damage, contributing to a healthier living and working environment.

Q) Can Wykamol LGM be used in retrofit projects?

A) Absolutely, Wykamol LGM is ideal for retrofit applications where additional waterproofing, vapour proofing, or gas proofing is needed. Its compatibility with various substrates and conditions makes it an excellent choice for upgrading existing buildings.

Q) What are the limitations of using Wykamol LGM?

A) While Wykamol LGM is highly versatile, it should not be applied in wet conditions or submerged environments before it has fully cured. Additionally, it is not suitable for applications where it would be exposed to constant mechanical abrasion or extreme temperatures beyond its specified range.

Q) How does Wykamol LGM handle water vapour permeability?

A) Wykamol LGM exhibits low water vapour permeability, making it an effective vapour barrier. This property is crucial in preventing moisture ingress that can lead to damp issues and structural deterioration over time.

Q) What certifications does Wykamol LGM hold?

A) Wykamol LGM complies with relevant British Standards for construction materials, ensuring it meets stringent quality and performance criteria necessary for building applications.

Q) How long does Wykamol LGM last once applied?

A) When applied correctly and maintained properly, Wykamol LGM can provide durable protection for many years, depending on environmental and operational conditions. Regular checks and maintenance can extend its effective lifespan further.

Q) Can Wykamol LGM be used in green building designs?

A) Yes, its environmentally friendly profile and contribution to improved indoor air quality make Wykamol LGM suitable for use in green building designs seeking to reduce ecological impact and enhance sustainability.

Q) What are the best practices for storing Wykamol LGM?

A) Wykamol LGM should be stored in a cool, dry place away from direct sunlight and extreme temperatures. Proper storage conditions will ensure the product maintains its efficacy and shelf life.

Q) Can Wykamol LGM be used in high humidity environments?

A) Yes, Wykamol LGM's low permeability to water vapour makes it well-suited for use in high humidity environments, where it helps to manage moisture levels effectively, protecting against damp and condensation.

Q) What impact does Wykamol LGM have on indoor air quality?

A) By blocking the ingress of radon and methane gases, Wykamol LGM contributes positively to indoor air quality, making it safer and healthier for occupants.

Q) Are there any health and safety concerns with using Wykamol LGM?

A) As an environmentally safe and non-toxic product, Wykamol LGM poses no significant health and safety risks when used according to manufacturer guidelines. Proper application techniques should always be followed to ensure safety.

Q) Can Wykamol LGM be applied over old coatings?

A) Yes, Wykamol LGM can be applied over existing coatings, provided they are sound and well-adhered. However, a compatibility test is recommended to ensure proper adhesion and performance.

Q) What training is required to apply Wykamol LGM?

A) Basic training in surface preparation and membrane application is recommended for individuals applying Wykamol LGM. This ensures that the product is applied effectively and safely, maximising its protective properties.

Q) How does Wykamol LGM compare to other membrane products?

A) Wykamol LGM stands out due to its quick-drying properties, environmental safety, and ability to be applied in a variety of conditions, including on damp surfaces. Its flexibility and strength also make it superior in terms of crack bridging and long-term durability.

Q) What technical support is available for Wykamol LGM applications?

A) Technical support for Wykamol LGM is available through the manufacturer, providing guidance on specifications, application techniques, and troubleshooting to ensure optimal results for every project.

Technical Data Sheet

Safety Data Sheet