Step One

Check the surface is even and level. Use packers if the substrate is not even and level. Packers that assist in providing a level substrate will stop stress fractures. Do not stress the profile by fixing to an uneven/non-level surface. If you do cracking will result.

Substrate

Always check the substrate is level before fixing Uni-Shape Mouldings. It is common to find precast panels, render, brickwork, block-work, AAC & FRC sheeting may not be true or maybe out of level. If this is the case simply use packers behind to level the profile during fixing. Uni-Shape comes in 2.4 or 3.0 metre lengths. It is advisable not to put any unnecessary stress on the profiles, otherwise cracking can occur with daily or seasonal thermal expansion and contraction. General cracking due to mishandling, etc is repairable on site.

Note:

In cutting, mitring and preparing, carpenters can use the same successful methods as for timber type plinths, architraves etc. when in exterior use. (ie treat cutting of Uni-Shape as you would timber lengths).

Step Two

Run a string line at the lower edge where the moulding will be fixed. At sufficient intervals drive in temporary anchors into the substrate. Position the profile and rest on the temporary anchors.

Positioning the Uni-Shape Moulding

It is most common to run a string line at the lower Uni-Shape Moulding edge or the outside edge in the case of a window reveal. Use a temporary anchor or small timber chock along the string line. Position the profile along this line and rest on the temporary anchor before permanent drill fixing to the substrate. Pre-drilling (including counter sink drilling) of the mouldings - on the work bench - prior to positioning is required. All profiles must be pre-drilled and countersunk (for the anchor heads to fit snugly below the surface) on the work bench prior to anchor insertion.

Step Three

Drill through the pre-drilled moulding and into the substrate and then counter sink the nylon anchor heads at least 3 mm below the profile surface. Tap home the anchor without stressing the Uni-Shape Moulding.

Fastening

Drill through the pre-drilled moulding and into the substrate with a drill bit to suit the size of the shank of the permanent anchor. Then mechanically fasten deep enough to countersink into the countersink cavity (already pre-drilled). The head of the anchor should be at least 3 mm below the surface of the Uni-Shape Profile. In brick/block substrate it is essential to fix into the masonry substrate and not into the mortar.
Tap home the anchor, taking care not to damage or stress the moulding. Over a 2.4 or 3.0 metre length profile you must (as a minimum) mechanically fix within 50 mm of each end and also stagger-fix one side then the other side of the profile at approximately 400 mm centres. In timber/steel framed substrates fix at each stud along the length of the Uni-Shape Moulding.

Note:

Use Nylon Anchors counter sunk heads and Easy-Drive Anchors. Uni-Shape Mouldings are fixed to FRC Sheeting with exterior Class 3 Timber screws with counter sunk heads. Large profiles should be fixed through the base FRC sheet and into the supporting frame. These fixing instructions only apply to standard stock products. Please check with your local Unitex technical representative for the preferred fixing method of custom-designed products. In corrosive environments (eg within 500 metres of the sea) stainless steel anchors are recommended. See also Surface Finishes (Step Eight).

Step Four

Use a putty knife to fill the anchor-fixing cavity with Unitex Putty. Rub the surface with a sponge until the surface matches the texture of the profile.

Step Five

From behind, seal both side edges of the Uni-Shape Mouldings.

Edge Sealing

When the full length of Uni-Shape Moulding is finally fixed into position, both side edges must be sealed between the substrate and the leading edges of the profile. A Polycarbonate Sealant with an expansion modulus of ±25% is to be applied. Uni-Sealant is recommended.

Note:

1. Acrylic/Water-based gap filler mastics are not to be used.
2. Sealant is applied to the rear of profile and is squeezed out to the leading edges upon fixing - leaving nil gaps.

Step Six

To join Uni-Shape lengths simply align and leave a gap of approximately 6-10 mm and mastic seal (over pre-fitted backer rod or backer foam) to a depth of approximately 4-6 mm.

Length to Length Joints

Uni-Shape Mouldings generally come in 2.4 or 3.0 metre lengths and are fitted together with a 6-10 mm (approximate) straight cut gap. The gap is filled with a Polycarbonate Sealant with a backer rod or foam filler behind. The clean surface is then scalloped. Fine visible pencil joints are the result. Cracking at a mastic joint will sometimes occur due to building movement, thermal expansion or a combination of drying/settling of the façade profile. In this case mastic can be re-applied at a later date.

Note:

All cut ends to be dry and dust-free prior to mastic application. Correct mastic application is half as deep as it is wide.

Step Seven

Always leave the same size gap in the profile as in the engineered building expansion gap joints.

Building Expansion Joints

Definition: Dissimilar substrate junctions, precast panel to precast panel junctions. Always leave the same size gap in the profile as in the engineered building expansion gap joints.

Note:

1. In many cases where the expansion joint gaps are ~ 20 mm - mastic between the Uni-Shape lengths is not used and the gaps remain open without sealant in between - aesthetically this can work well, especially between precast panels in commercial projects.
2. For the expected movement of substrates your Builder and Engineer must design their projects with building movement in mind. Generally for good building practice expansion joints/movement joints should be constructed at least every 6 m in every elevation.
3. FRC sheeting (cladding) - the gaps between FRC sheets butt jointed (3 mm) are not, for this purpose, to be taken as expansion joints. It is the responsibility of the Builder and Architect or Engineer to predict the likely building movement, surface thermal movement etc. prior to Uni-Shape installation. Expect to have a minimum 10 mm expansion/slip joint at least every 6 m in every elevation. Unitex will not take responsibility for bad design that does not allow for substrate movement.
4. In the case where a movement joint is designed around a structure (eg. at the junction of FRC sheet on an upper floor wall to Block-work or Brickwork on a lower floor), then at this movement junction, the Uni-Shape profile will be fixed to one substrate only and float over the movement joint. It is not to be fixed to the adjoining substrate. (The movement joint is neatly hidden behind the Uni-Shape Moulding).

Step Eight

To keep the aesthetic appeal it is important not to overcoat the Uni-Shape Mouldings with texture, as the Uni-Shape corners are crisp and sharp. For best results coat with a Uni-Flex Membrane coating (satin) or Uni-PTC (flat) in the colour of your choice. Coverage is approximately 1 litre per m².

Installation of void-formed Uni-Shape Mouldings

• Window Heads
• Parapet Mouldings
• Corbels
• Large Scotias
• Mid Level Stringers

What you will need before starting the job:

Material required

• Unitex UPC200 Putty*
• Uni-Flex Membrane Coating or Uni-PTC*
• Mechanical Fasteners - Nylon (Easy-drive) Anchors*
• Class 3 Timber Screws (for FRC Sheeting)*
• Stainless Steel Anchors (marine environments)*
• Backer Rods/ Foam Backing Material (Expand-O-Foam)*
• Packer Plates*
• Polycarbonate Sealant*

* Available from Unitex

Tools required

• Tape Measure
• Carpenter's Pencil
• String Line
• Level
• Putty Knife
• Sealant Gun
• Drill and bits
• Tungsten Tip Saw & Mitre Box or
• Drop Saw (sharp and clean), check your angles and measure twice to cut once.

The Uni-Shape Mouldings with voids have an average 10-12 mm (approximately) layer completely around the void. It is reinforced, and a fully integral part of the moulding. The upper and lower leading edges of these styles are more solid with around 20-30 mm depth of a lightweight-cement fibre-reinforced cover.

Fixing these is the same as for solid Uni-Shape Mouldings with the difference being that, in a parapet style moulding the top edge fixing is at an angle of 45 degrees through the top into the rear of the moulding and then into the substrate with an Easy-drive type larger Anchor. The head of the anchor is countersunk (pre-drilled cavity) into the Uni-Shape 20-30 mm covering layer on the top edge of the moulding.

All other instructions are, (adjusted for larger product sizes where applicable), as previously explained for solid Uni-Shape Mouldings.

Note:

Some conditions (other substrates, Uni-Shape Moulding types and on-site configurations) may require you to modify the above methods to suit.

Installation of custom-designed Uni-Shape Mouldings

Because of the almost infinite options of shape and size available for custom-designed Uni-Shape Mouldings it is not possible to provide, in this brochure, the intricate details for fixing every shape. When ordering your custom-designed Uni-shape Moulding contact your local Unitex technical representative for specific recommendations.

Hole and Surface Damage Patching

Use a spatula (putty knife) to fill the cavity with Unitex patching compound UPC200 Putty. When the cavity is full, rub the surface with a sponge to match the surface texture of the profile (ie not glassy smooth but rather a sandy smooth effect like the mouldings).

Note:

1. In areas of high humidity and/or wet conditions the UPC200 Putty may require an additional 5-10% cement for faster drying (mixed on the putty board).
2. UPC 200 Putty is not designed for application in movement joints, adjoining lengths of mouldings, or in mitre cuts etc.

Hairline Crack Repairs

• Cut v-line groove (small tool/Stanley knife)
• Fix anchors approximately 20 mm on each side away from the crack (two per side)
• Mix UPC200 and apply to v-line
• Wait 24 hours to dry
• Sand smooth as desired
• Apply membrane to match existing colour

Moulding Crack Repairs (in situ)

• Cut v-line groove (small tool/Stanley knife)
• Fix anchors 20-50 mm on each side away from crack (two per side).
• The number of fixings depends on the size of moulding eg If moulding width > 100 mm need four fixers
• Mix UPC200 and apply to v-line
• Wait 24 hours to dry
• Sand smooth as desired
• Apply membrane to match existing colour

Before	After