MASTERFORM FITTING INSTRUCTIONS

FITTING INSTRUCTIONSMASTERFORM®

Uniclass JH7

December 2019

1. WHAT IS MASTERFORM?

Masterform is an alternative flashing material providing a long-term waterproof covering to areas where traditional flashing materials such as lead, zinc and copper would normally be used. It is capable of being installed using the traditional detailing normally associated with these materials.

Masterform is a laminated polymer sheet material with an aluminium mesh embedded within the thickness of the sheet. It has been designed and manufactured to meet the specific requirements of a weathering material that is flexible and malleable.

Its physical properties being similar to those of lead enable it to replicate most common leadwork details. It has excellent stretching properties allowing it to be easily dressed and formed to pantiles and other corrugated roofing profiles. It can stretch up to 60% of its length (as rolled out) and 20% of its width (the width of the roll).

Whilst Masterform cannot be ‘welded’ it can be joined to itself by means of a lap that is completely and permanently waterproof. Joints in Masterform are formed using the MMS sealant which provides a completely waterproof joint.

SUITABLE USES

• chimney flashings• apron flashings• tiled and slated valley linings• ridge cappings• abutment flashings• cornice weathering• parapet and wall cappings• small roof areas e.g. porches• roof light and window flashings• solar equipment flashings• shop front flashings• soakers

fitting instructions

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2 Helpline: 01763 295828 | www.nicholsonsts.com

Important information; Masterform should not be used in situations where it will be subject to water run off from copper, asphalt or bitumen roofing. In these circumstances the warranty will be void. When fixing Masterform use either stainless steel or aluminium nails. Copper clouts or clips should not be used.

2. THE MASTERFORM SYSTEMThe Masterform weathering system is made up of four main components;1 The Masterform flashing material – Supplied in 4m long rolls in 9 different widths from 150-620mm. 2 Masterform MMS – A mastic form of the sheet polymer which is used for joining, adhering and sealing.3 Masterform MBA – A Bonding agent used in the jointing process to hold two pieces of Masterform together whilst the

MMS cures.4 Masterform Trims – these aluminium trims provide continuous support at the drip edges and are supplied in 1m lengths

with two different drip dimensions.

3. MASTERFORM MATERIALThe Masterform material comes in roll form with a polythene separating layer to the under surface. Whilst this material is not a self-adhesive product, two surfaces of Masterform will bond together, if left touching, over time. For face work the polythene film can be unwrapped so that it protects the upper side of the product. To do this unwrap the film completely on a roll until the film is starting to unwind the material. Cut off the excess and continue to work.

4. TOOLS AND EQUIPMENT REQUIREDNormal sheet metalworking tools can be used for cutting, dressing and fitting Masterform. The use of rubber or rubber faced tools is not recommended as these may leave marks on the surface of the product. High density plastic dressing tools are the most effective for dressing Masterform but wooden tools and dressers may be used providing they are smooth.

When dressing Masterform into profiles a rounded tool should be used and care should be taken to stretch the material evenly and not just at one point. Care must be taken when stretching or ‘bossing’ not to damage the surface of the material. If necessary a cloth or rag can be placed over the area of Masterform to be dressed to prevent damage to the surface. Should any small imperfections to the surface occur as a result of dressing a small amount of the Masterform MMS can be applied locally.


Helpline: 01763 295828 | www.nicholsonsts.com 3

5. PREPARATION OF SUBSTRATE

The substrate upon which Masterform is laid should be clean, smooth and free of any sharp protrusions which might damage the sheet. The substrate should also be continuous with no large gaps or holes into which the Masterform may sag. Where the existing substrate consists of uneven or rough boarding an overlay of plywood should be fixed to the existing surface to provide a suitable surface for installing the Masterform on.

Masterform can be laid directly on cementious surfaces so long as they are cured, dry and free of sharp protrusions. For porous surfaces the use of a proprietary sealing product is advised so that the Masterform can be adhered properly to the substrate using the Masterform MMS.

6. SETTING OUT

Masterform is a thermally stable product and no consideration need be given to allowance for thermal movement. However, it is advised that lengths of Masterform are cut in to manageable sizes for handling purposes. Laps, welts, rolls and joints can be adjusted to suit the roll length or to match other construction features.

7. MARKING OUT AND CUTTING

Masterform can be marked out using a chalk line or blunt pencil. Sharp or pointed objects should not be used. When marking up tabbed details sufficient material should be allowed to provide enough contact area to ensure a good bond.

8. INSTALLATION

Masterform should be laid with the smoother side facing uppermost. As Masterform is a soft material, it should be adequately protected as work proceeds and protected from damage by sharp objects.

Masterform may be nailed into position just as any other flashing with the exception that the fixings should be either stainless steel or aluminium clouts. The fixings should not be visible and must be protected from the weather by a lap or cover piece.

Masterform can be wedged into a chase in masonry. Ensure that the chase is at least 25mm deep by 10mm wide. Once the flashing is inserted into the chase, a 20mm wide strip of Masterform can be rolled up and used as wedging material. It is suggested that, due to its flexible nature, Masterform is pointed with an exterior grade flexible sealant. The Masterform MMS may be used for this as it adheres well to most building substrates. If preferred a cement based pointing mortar can be used.

Masterform can also be simply adhered to brick, steel, glass and most other construction materials using the Masterform MMS. A preliminary adhesion test is recommended to determine that a satisfactory bond can be achieved to the substrate in question.

9. JOINTING

Masterform can be joined using various methods;

1. Lap joints - Vertical lap joints should always have a vertical lap of 100mm to the surface being weathered. Horizontal lap joints should be a minimum of 100mm but increased to 150mm where severe exposure is likely. The exposed overlapping layer should be restrained against wind uplift in all cases.

2. Welted joints - Welted joints should not be used unless there is sufficient fall to allow water to drain freely from the weathered surface. Welted joints should not be used where they might cause localised ponding or become submerged.

3. Bonded joints – Masterform may be bonded to itself in a lap joint. This will provide a waterproof joint when carried out in accordance with these Masterform Fitting Instructions. Bonded lap joints should be a minimum of 30mm wherever possible.


10. PREVENTING WIND UPLIFT

As with all flashing materials, it is important to restrain the free edges of flashings and weatherings becoming displaced or lifted in strong wind conditions using one of the following methods;

1. Continuous clipping. This would normally be used where there is a drip edge such as at the perimeter of a dormer top, dormer cheek, parapet coverings and cornice cappings. The Masterform Trim’s which are available in a 50mm and 75mm downstand can be used to achieve this detail. Alternatively, these restraining clips can be fabricated from sheet material such as stainless steel, aluminium and galvanised steel. Copper should not be used.

2. Clipping at 300mm spacing. This would normally be used where the flashing is dressed over an upstand or onto slates or tiling. The clips should be 50mm wide and can be of Masterform or other suitable material as 1) above. The clips should be adhered to the substrate below using the MMS Mastic/Sealer so that the restraint is near the edge of the flashing. If Masterform clips are used, the underside of clip should also be adhered to the top of the flashing to avoid it coming undone in extreme conditions.

3. Continuous adhering with MMS Mastic Sealer. This can be used in any situation where Masterform is dressed onto a substrate or upstand. The Masterform is dressed onto a continuous bead of mastic within 25mm of the edge of the Masterform flashing. The substrate should be clean, dry and free from grease and dust. This can be combined with the clipping at 300mm centres where exposure to severe conditions is likely.

4. Spot adhering with MMS Mastic Sealer. This should be carried out on all flat areas where Masterform is used to prevent wind suction affecting Masterform. These would include parapet cappings and cornice coverings. The MMS Mastic Sealer is used at 350mm centres in a grid pattern.

11. DRESSING AND FINISHING

Masterform can be generally dressed and formed in the same manner as lead using similar tools. Care should be taken when stretching the material not to overstretch the product to avoid damage. Consideration should be given to the way that details are cut out of the roll as the product has a greater stretch in one direction as marked on the reverse of the product. When a section of work is finished Masterform can be cleaned using a soft cloth and water.

12. MATERIAL ORIENTATION

The Masterform material has excellent stretch properties but these are different for the length and width. The material is always in the same orientation on the roll whatever the roll width. This means that as the material is rolled out there is always 60% stretch in the length and 20% stretch in the width (see illustration above). This should be noted as certain details are reliant on the material being in the correct orientation for them to work.

A GUIDE TO SOME COMMON DETAILSThe details on the following pages are given as a reference. Whilst it is important that the bonding requirement of any detail is carried out in the described manner using the system adhesives it is acceptable to change the formation of the detail providing that the end result is neat, watertight and free-draining.



Flat bonded lap joint

1 Prepare the two surfaces of Masterform to be joined ensuring that they are clean and dry. Apply a continuous bead of MMS 6 - 8mm dia. Apply a line of MBA behind the mastic as shown.

2 Press the surfaces together carefully. Work along the joint. Ideally a small amount of the MMS should squeeze out of the joint to its entire length. The MBA will cure very quickly holding the joint in position.

3 Finish the joint by wiping away any excess MMS from the joint. Proprietary hand wipes can be used to clean unwanted MMS from the joint.

Internal corner

1 Mark up the corner position on the sheet using either a chalk line or blunt soft pencil.

2 Using sharp snips or a knife make cuts as indicated by the red lines.

3 Fold up the sides as indicated applying a 6 - 8mm bead of MMS to the rear face of the inner leaf. Apply a small amount of the MBA behind the MMS. Take care that this does not run down to the substrate below.

Welted joint

1 Fold back the ends of the sheets to be joined ensuring that the return does not close up.

2 Pull the two surfaces together to engage the welts over the length of the joint.

3 Dress the welt flat firmly and set-in the over-cloak material in along the welt.



MT50 / MT75 welted drip

1 The Masterform MT50 or MT75 should be fixed along the drip edge using suitable clout nails or small stainless-steel screws. Alternatively, they can be bonded into place using the MMS adhesive. In this case time should be given to allow the adhesive to cure prior to overlaying with Masterform.

2 Wherever possible the MT50 / MT75 should be left flat until the Masterform material is in place and welted around the leading edge.

3 Turn the drip edge down working along carefully to fold the trim along the pre-perforated line.

4 Press the two surfaces together. Ideally a small amount of the MMS should squeeze from the joint. The MBA will cure very quickly holding the joint in position.

5 Apply a small fillet of MMS to the internal corner. At the corner point the MMS should be a minimum of 2.1mm deep.

6 Finish the joint by wiping away any excess MMS from the joint. Proprietary wipes can be used to clean unwanted MMS from the joint.

Pipe flashing detail

1 Cut a length of the Masterform material ensuring that its length is sufficient to go right around the pipe and overlap by 25mm minimum. Turn out a lip along the length of the material of 15-20mm. Ensure that the orientation of the material is as shown.

2 Gently pull the material around a pipe that is the correct diameter and dress the overlap flat. Using a dresser or fingers straighten the lip around the lower edge. Using the MMS and MBA adhesives make a joint to the overlap.


Masterform is a unique alternative flashing material providing a long-term waterproof covering to areas where traditional roofing materials such as lead, zinc and copper would normally be used. It is capable of being installed to the traditional detailing normally associated with these materials which are inherently vulnerable to theft due to scrap metal values.


Unit 13, Wireless Station Park, Chestnut Lane, Bassingbourn, SG8 5JH

t: 01763 295828e: [email protected]: www.nicholsonsts.com

MASTERFORM FITTING INSTRUCTIONS

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