VVMM ZZIINNCC DDEEXXTTEERR®®

■ Patented, pre-formed VM ZINC® roofing and cladding system for use onroofs with slopes of 2:12 and more

■ Quick and easy to install

User Guide for Roofing Application

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Dexter®Top quality zinc, rapidly laid

Description of the system• DEXTER® is a patented cladding system for both roofs and facades. It is designed to meet the laying

requirements of the professional without the need for special mechanized tools. The useful dimensionsof each standard element are 15 3/4” x 32 7/8” (400 x 835 mm). The overall dimensions are 15 3/4” x39 7/8” (400 mm x 1013 mm). This means that 3 elements can cover an area of 10 3/4 square feet (1 m2).Each element is fixed onto the support at the top using a sheet clip and along that side with the obliquefold using two side clips.

• All DEXTER® elements are made from VM ZINC PLUS® 0.7mm. The elements are assembledlongitudinally with a centre-to-centre distance of 15 3/4” (400 mm) by simply interlocking the sides intoone another. The left side of each element has an oblique fold and the right side a rounded profile. Theheight of the joint formed on interlocking is 1 3/8” (35 mm).

• Transversally, the elements are assembled using double-welt joints. This meets the requirements ofroofs with low slopes of at least 2:12(17%) in high snow areas it is 3:12 (25%).

• The transverse joints overlap by 6 1/4” (158 mm) and the side with the rounded profile has a 7 7/8” (200mm) zone where the profile narrows so as to facilitate overlapping.

• As a result of the production process used, the very slightly conical shape of the DEXTER® elementsallows for thicknesses in metal encountered during assembly. The installation is therefore easy, rapidand accurate.

• The DEXTER® system is laid from right to left like roofing tiles. The transverse joints can be staggeredor aligned.

• The DEXTER® system is available in QUARTZ-ZINC®, a dark gray zinc which looks like naturallyweathered zinc.

Aligned DEXTER® elements Staggered DEXTER® elements

ApplicationsVentilationGenerally, zinc needs to be installed in a ventilatedapplication, however, the DEXTER® system uses VMZINC® PLUS which has a protective coating on theunderside. This means the DEXTER® system can beinstalled without ventilation directly over a roofing deckseparated by VM ZINC® Roofshield.

Slope for roofs• Minimum Slope: 2:12 ( 17%).• Maximum slope: vertical.• In areas particularly exposed to severe weather

(coastal or mountainous regions, or Areas with highsnowfall) minimum slope 3:12 ( 25%)

Authorized roof decks (slopes of 7:12 (60%) or more)The wood decking should conform to the codes ofpractice for zinc roofing. For slopes of 60% or more, non-continuous roof deck cannot be used unless theelements are laid with 3 side clips (see section entitled“Installation on page 7).

ClimateIn the non-mountainous regions there are norestrictions. In mountainous regions or areas of heavysnowfall a supplementary waterproof membrane mustbe used underneath the ventilated airspace.

Wind actionThe method of laying (aligned or staggered joints) andthe number of side clips used will determine theresistance of the DEXTER® system to wind stressaccording to the table below.The use of 3 side clipsallows DEXTER® to meet increased stress occurring onthe edges in exposed areas.

The amount of stress calculated must takeinto account the characteristics of the roof(height, slope, local stress at the edges,corners and eaves, exposure) and must belower than the admissible resistance of theDEXTER® system.

Admissible resistance (per 10 3/4 ft2 (1 m2))

Number of Side Clips 2 3

Aligned joints 28 lb/ft2 (1333 Pa) 39 lb/ft2 (1875 Pa)

Staggered joints 32 lb/ft2 (1533 Pa) 45 lb/ft2 (2156 Pa)

Dexter®Top quality zinc, rapidly laid

Met

hod

of la

ying

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ComponentsThe DEXTER® elements are manufactured from VM ZINC® PLUS. This product has a protective undersidecoating. The thickness of the panels is 24 gauge (0.7 mm). The weight of the system per 10 3/4 ft2 (1 m2)is 16.75 lb (7.6 kg) on the standard part of the roof without the support.

ComponentsPanels and fasteners

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VM ZINC 1/2 DEXTER®

Overall dimensions : 15 3/4” X 23 1/2” (400 x 597 mm) Useful dimensions: 15 3/4” x 16 1/2” (400 x 436 mm)Packaging: Packs of 6Weight of 1 element: 3.45 lb (1.56 kg)

Side withoblique fold

Zone with smaller profile

596,

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Lower edge withfinishing clip

15 3/4" (400 mm)Safety fold

Riveted single welt

Side withrounded profile

Zone with smaller profile

39 7

/8"

(101

3 m

m)

Lower edge with finishing clip

15 3/4" (400 mm)

Side withoblique fold

Safety fold

Riveted single welt

Side with rounded profile

VM ZINC DEXTER®

Overall dimensions: 15 3/4” x 39 7/8” (400 x 1013 mm)Useful dimensions: 15 3/4” x 32 7/8” (400 x 835 mm)Packaging: Packs of 6Coverage: 3 elements = 10 3/4 ft2 (1 m2)Weight of 1 element: = 6 lb (2.54 kg)

Fixing SystemEach element is fixed onto the support at the top using a sheet clip and along the side with the oblique foldusing two side clips.

ComponentsP a n e l s a n d f a s t e n e r s

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Ventilated ridge The ridge panel is a pre-formed accessorywhich clips into the top of the DEXTER®

element at the ridge to form the joint with theridge.

Seam sliderClips onto the rounded profile of the DEXTER® to cover the upturned edges of the ridge panels and forwelting into the folds of the ridge panels.

Possible solutions

Flashing

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6 1/4" 160 mm)

8" (205 mm)

Flashing accessories

EavesInstalled with a galvanized steel stiffener and sheet clips.

ValleyValley flashing with double welt installed with sheet clips to allow thermal movement.

FlashingPossible solutions

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10 1/8" (258 mm)

160˚7 " (180 mm)

Installation

Roof deckInstallation must conform to the layingrecommendation for continuous ¾"plywood.

During laying, use a ruler to ensure thatmisalignment between two battens isno greater than 1/16"( 2mm).

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Dire

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layi

ng

First batten

1

2

3Li

ne o

f gre

ates

t slo

pe

13 7/8" (352 mm)

7 1/4" (185 mm)

16 3/8" (417 mm)

16 3/8" (417 mm)

Staggered joints

Laying with staggered joints

Quick and easy to install

Laying the panelsDEXTER® is laid from the bottom to the top of theroof in parallel vertical rows to starting at the rightangle formed by the eaves and the edge.

It is essential that the longitudinal joint lines areparallel to the line of greatest slope.

Starting from 90° angles, mark out on theassembly deck axes of the longitudinal joints(centre-to-centre distance of 15 3/4” (400 mm)),taking into account the particular characteristics ofthe roof. It is advisable to mark out a horizontal lineat right angles to the top of each row in order tofacilitate the positioning of the elements at the timeof laying.

Regions with heavy snowfallInstallation of a supplementary waterproofmembrane is necessary: a protective layer of VMZINC® Roofshield should be placed under theventilation airspace.

InstallationQuick and easy to install

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Laying with aligned joints

First batten

13 7/8" (352 mm)

7 1/4" (185 mm)

16

3/8"

(41

7 m

m)

Dire

ctio

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layi

ng

1

2

3

32 7

/8"

(835

mm

)

16 3

/8"

(417

mm

)

Dire

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layi

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First batten

Aligned joints

With the eaves flashing in place and themarking done, the DEXTER® elements arelaid as follows:

Installation from eave to ridge1. install the first panel on the right side ofthe eave according to your chalk lines

2. place the side with the rounded detailonto the side of the lower DEXTER®

element

3. Lay down the DEXTER® and snap theside with the oblique fold of the DEXTER®

element

4. Insert the hem at the base of the upperDEXTER® into the single welt of the lowerDEXTER® and push upwards

Interlocking should not be continued all theway because a play of approximately 1/8”(3 mm) should be left between the 2successive DEXTER® elements. Thisallows the zinc to expand and contract withvariations in temperature.

Installation from right to leftOnce the first vertical row has been laid,the adjacent rows are completed accordingto the same principle. When DEXTER® islaid horizontally with staggered joints, therow at the eaves consists of alternating aDEXTER® with a half DEXTER® element(starting element) in order to create amisalignment of half an element betweenthe vertical rows.

Step by step instructions

Installation

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Standard part of the roof

1

2

3

Step by step instructions

Laying horizontal panels

Fixing the DEXTER ® elements

The DEXTER® elements are fixed at the top by a sheet clip and by 2 sideclips (or 3 - see table on wind action, p. 3), which are placed along theside with the oblique fold.

1. When placed in position, each DEXTER® needs to be immediately fixedat the top by a sheet clip inserted into the centre of the safety fold.

2. The side clips are put in place during or after the laying of a completevertical row. They are fixed along the side with the oblique fold every16 3/8” (417 mm) for 2 clips, and 11” (278 mm) for 3 clips*,except at theeaves where the spacing between the first two clips is 13 7/8” (352 mm)for 2 clips, and 8 3/8” (212 mm) for 3 clips*, the first side clip beingpositioned at the eaves 7 1/4” (185 mm) from the base of the firstDEXTER®.

* The figures for 3 side clips per element may be required in situations of high wind. See table on wind action on page 2.

Basic toolsDEXTER® is designed to be laid on the standard part of the roof withoutspecial mechanized equipment, DEXTER® requires the use of thefollowing simple tools for treatment of particular details:

• Cranked seaming tongs• Shears• Metal saw• Plastic hammer• 3’ (1m) folding machine or seaming tongs• Cordless screwdriver

Installation

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A range of flashing accessories allows treatment of standard specific details in accordance with thefollowing indications. However, the treatment of flashings can be carried out according to traditionalzinc-laying techniques conforming to the relevant codes of practice.

EavesThe eaves flashing should be positioned so as toprovide a lower continuous ventilation space of atleast 1/2” (14 mm). In the case of staggered joints,a DEXTER® and a 1/2 DEXTER® are usedalternately at the eaves. The first side clips shouldalways be positioned 7 1/4” (185 mm) from theeaves.

ValleyValey slope < 2:12 (17%) or length > 26’ (8 m)It is advisable to form a traditional valley strip(with a soldered single welt) with an appropriate watercollection section. It is necessary to mark the position of each element with chalk lines to ensure thealignment between the seams.

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Eaves

Valley

Installing flashing accessories

Installation

Installing flashing accessories

Installation

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Ridge

Determine the useful length remaining to be coveredat the top of each row (distance between the ridge andthe lower edge of the double welted seam of the lastelement). If this distance is less than 320 mm it ispreferable to use half DEXTER® elements instead ofentire DEXTER® elements to limit wastage. Theelements situated along the ridge should be cut off atthe base and then folded to recreate the original edgewith finishing clip. In order to fix the top of the last,DEXTER®, a notch should be made on the oblique foldabove the last side clip.

The following detail can be used for the upperventilation outlet:

With the galvanized steel ridge profile and the last rowof DEXTER® elements in place, the ridge panel is fitted by inserting it into the welted seam of the last DEXTER® element.The longitudinal joint of the ridge panel is overlapped by the 200 mm seam slider which clips into the folds of the ridgepanel. Once in position, the sides of the sliders are closed using pliers.

Rip Cap Parts

Rip Cap Section

HipFirst install a hip batten of 2” (50 mm) x 4” (100 mm)in height, then turn up the DEXTER® elements to aheight of at least 2 1/8” (55 mm) along the batten.The turned-up edges need to be fixed with a sheetclip. Corners are waterproofed using a dog-ear fold.The hip cap is clipped over a galvanized cleat.

Wall AbutmentThis is filler text. I don’t have text at the moment that should go here. Cansomeone at VM ZINC provide me the the correct text?

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Hip

Wall Abutment Parts

Installing flashing accessories

Installation

Wall Abutment Section

Installing flashing accessories

Installation

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GableTo fix the DEXTER® elements at thegable, it is necessary to unfold theside clips to provide an anchorage inthe rafter or in the gable board. Thetop of gable board must be flush withthe top side of the roof deck.

1. If marking-out of the roofrequires modification to thewidth, either to the right or the leftof the DEXTER® elements situatedat the edges: After cutting theDEXTER® elements to therequired width, an upturn will beformed on each element in therow concerned (height 1 1/4” (32mm) with a horizontal fold of 3/16”(5 mm) on which the unfolded sideclips will be positioned as on thestandard part of the roof. Acontinuos galvanized steelstiffener, installed prior to theDEXTER® panel, supports thegable flashing.

2. If marking-out of the roof doesnot require modification of thewidth of the DEXTER® elementssituated at the edges:

Left edge: Secure the clips on the side of the element with the oblique fold as for the standard part of the roof.

Right Gable: Crimping rounded upstand to create an upturn with a horizontal fold. Sheet clips hold the last DEXTER®

element in place until the gable flashing is installed.

3. Edge flashing: The flashing is hooked in the galvanized steel stiffener and then criped to the panel upturn.

Gable Section

Ventilation pipe, 11 34” (300 mm) in diameterTo provide an adequate channel forVentilation pipe, cut a DEXTER® elementleaving at least 2” (50 mm) of the elementon all sides (maximum diameter of cut =11 3/4” (300 mm)). Waterproofing isensured using a soldered casing.

Chimney surroundPenetrations such as chimneys andskylights are treated directly on-site.

Front of stackAs for treatment of the ridge, a flashing ismade by turning up the DEXTER® element3 1/2” (90 mm) and using a 7 7/8” (200mm) seam slider.

Rear of stackUse a separate rear-stack finishingcomprising:

1. A fixing plate soldered at the top,allowing the DEXTER® elementssituated in the upper part to be clipped inplace.

2. A safety fold allowing the flashing to befixed onto the support using sheet clips(see Diagram 1). The rear of stack canalso be finished using DEXTER®

elements the sides of which have been flattened before laying. The junction and waterproofing of theseelements are ensured by continuous soldering (see Diagram 2).

3. The lower part of the rear-stack finishing is locked into the single welts of the lateral DEXTER®

elements.

InstallationAround Chimneys and other objects

Treatment of penetrations

Diagram 1: Chimney stack with separate rear-stack finishing

4" (100 mm) min

Rear of chimney with soldered securing strip

Soldered bracketSlider

1/2 DEXTERcompleting thesurround

DEXTER completing the surround

DEXTER completing the surround

4"

(100

mm

) m

in

15

SliderSoldered bracket

Half-DEXTERcompleting thesurrond

4" (

100

mm

) m

in

Soldered DEXTER completing the surround

Half-DEXTERcompleting thesurrond

Diagram 2: Solution using soldered DEXTER® elements

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Please note: If the space between the sides of the stack and theedges of the DEXTER® elements is less than 4” (100mm), a dissymetrical water channel can be installedagainst the side of the stack to direct the water flow at4” (100 mm) on the upper side.

Peripheral waterproofing of the stack is ensured byturning up the sides of the surrounding roofing elements3 1/2” (90 mm) against the brickwork and by placingsoldered brackets at each corner. The hole should thenbe topped with wall abutment flashings. The linearity ofthe horizontal joints (with or without staggering betweenrows) can be maintained using elements made tocomplete the surround welted into the rear-stackflashing and cut at the base to the desired length.

InstallationAround Chimneys and other objects

RepairingReplacing damaged elements

Replacing a damaged panel

15 1/4" (388 mm) external dimension

1" (25 mm)

32 1/4" (818 mm)

1 1/2" (40 mm)

1 5/16" (33 mm)

3/4" (20 mm)

Rounded profile, 1/2" (14 mm) in diameter

3/4" (20 mm fold)

3/4" (20 mm)

Soldered junction of sides

Joint closed with pliers

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If accidental damage occurs to a DEXTER® element, repair as follows:

1. Make a DEXTER® (repair element) comprised of:• a right side with a rounded profile of 9/16” (14 mm) in diameter, unclosed along its entire length,• a left side without fold,• a fold on the lower edge identical to that of the preformed DEXTER® element,• a straight top without safety fold and single welt.The base of this element has the same geometry as the standard

DEXTER® elements but is reduced in width by two thicknesses of metal.

2. Slide the left side of the repair element between the left side of the damaged DEXTER® and the rounded profile of theadjacent DEXTER®.

3. Lay the repair element over the existing DEXTER® by covering the rounded profile with the 14 mm unclosed roundedprofile.

4. Slide the repair element upwards so as to insert its upper edge under the upper DEXTER® and its lower fold under thelower edge of the damaged DEXTER®.

5. Close the rounded profile (14 mm in diameter) along the entire length of the

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RepairingReplacing damaged elements

AdditionalSee what else VM ZINC® has to offer

Additional AssistanceIf you require any technical advise with regard to the specification of this product, including non-standard requirements, please contact your local Umicore Building Products USA, Inc. office in Raleigh,North Carolina, or on the west coast in Portland Oregon.

TrainingPRO-ZINC is a service provided by Umicore Building Products USA, Inc. which provides comprehensivetraining on every aspect of utilizing zinc as a building material. We offer a variety of classes in course lengthsof 1 - 3 days. A workshop seminar with mock-ups provide the best solutions in a comfortable environmentwithout the daily pressures associated with the actual job site.

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Additional OfferingsUmicore Building Products USA, Inc. offers a wide range of zinc products for roofing and building facades.We provide several “pre-formed” solutions as well as zinc in coils and sheets to be custom profiled usingtraditional metal techniques such as single or double lock standing seams, and batten (roll cap).

Some of our additional offerings include:

• VM ZINC® PLUS - coated zinc for warm roof and incompatible substrate applications• Compact Roof Assembly - warm roof applications• ADEKA - diamond shaped individual elements• Premier Performance System (PPS) - highly engineered rainscreen system• Flat Lock Seam - flat facade solution• Corrugated Panels - waved profiles used for facades• Ribbed Industrial Roofs - for long curved roofs

* Disclaimer: VM ZINC Inc. makes all efforts to ensure the technical accuracy of this information. We reserve the right to makechanges to this guide, at any time and without notice, as the need may arise. While all technical information and suggestions hereinare believed to be accurate, nothing stated herein is to be taken as a warranty, expressed or implied. Responsibility for review andvalidation remains solely with the design authority or other authority having jurisdiction.

Umicore Building Products USA Inc.

Headquarters: 3120 Highwoods Blvd. � Suite 104

Raleigh, North Carolina 27604phone: 919-874-7173

fax: 919-874-7140

West Coast Office:208 SW 1st Ave. � Suite 340

Portland, OR 97204phone: 503-827-0600

fax: 503-827-0770

email: info@vmzinc-us.comweb: www.vmzinc-us.com

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