Single Skin Box Profile Sheeting

Introduction

The following details are a guide to aid during installation of single skin sheeting, it is not meant to be a definitive guide as many different factors can contribute to the fixing of sheets and different manufacturers will have their own installation instructions.

 

Handling & Storage

Coverworld UK Ltd’s profiled sheeting is designed to be delivered to site in packs, the majority of which will come with cardboard protection and shrink wrapping. In certain cases we may use a cover sheet for the top or a packer sheet for the bottom to minimize damage. The maximum pack weight we will deliver is 2 tonnes and wherever possible suitable offloading equipment should be made available on site. The packs can be off-loaded directly onto the roof, or to a storage area, which should be dry, flat and well away from traffic. Packs may be stacked using suitable wooden bearers or packers and these bearers should be placed above each other at no more than 900mm centres. You must handle Coverworld UK Ltd’s profiles carefully to avoid marking weather sheets or liners. Packs must be opened carefully to avoid marking the sheets and all sheets should be lifted from the pack not dragged. As always observe site health and safety procedures and the results of manual handling and other assessments.

 

Preparation

Before fixing any sheet you should check the squareness and accuracy of any steelwork or support systems and also determine the direction of the prevailing winds. Carefully check all sheets before fixing to identify any damages or material inconsistencies. Ensure you have the correct fixings, fillers and sealants and have sufficient quantities of each before attempting installation.

 

INSTALLATION

Roofing – General Sequence

  1. Lay and fix sheeting as shown in the laying sequences shown on the next page (diagram 1)
  2. Fix and secure flashings using foam fillers (where necessary) and butyl sealants to ensure weather tight junctions.

 

Roofing – Single Tier Laying Sequence

The following sequence applies to sheeting on single tier roofs.

  1. Lay the first sheet with the overlap edge to the gable, away from the prevailing wind and use a string line or laser level to ensure you are laying the sheet straight and true. Fix the sheet through the valley or crown (see manufacturer for details) using a suitable fixing.
  2. If necessary (see manufacturer for details) apply a strip of butyl sealant along the top of the underlaps crown, both surfaces receiving the sealant should be clean and dry to aid adhesion and at joints the sealant must be overlapped by a minimum of 25mm not butted together.
  3. Lay the second sheet with the overlap crown over the underlaps crown of the first sheet and secure with suitable fixings.
  4. The side laps can be sealed at 400mm centres with either a rivet or self-drilling fixing (see manufacturer for details) dependent on the profile and site situation.
  5. Continue to lay the sheets across the width of the roof continually checking the alignment of the sheets and correcting / adjusting any deviations as necessary.

 

Installation Instruction 1

Diagram 1

Roofing – Multiple Tier Laying Sequence

On a double or multiple tier roof lay the sheeting as shown in the diagram above.

 

  1. Lay the first sheet (1) with the overlap edge to the gable, away from the prevailing wind and use a string line or laser level to ensure you are laying the sheet straight and true. Fix the sheet through the valley or crown at every purlin except the top one using a suitable fixing.
  2. Apply 2 runs of 6×5 butyl sealant along the top of the sheet and one run down the top of the underlap crown for the full length of the lap (diagram 2). Both surfaces receiving the sealant should be clean and dry and at joints the sealant must be overlapped by a minimum of 25mm not butted together.
  3. Lay the next sheet (2) in the sequence with its overlap edge to the gable and the bottom of the sheet lapping the top of the first sheet. Fix the sheet through the valley or crown (see manufacturer for details) using a suitable fixing.
  4. Apply a run of butyl sealant to the underlap crown of the first 2 sheets (diagram 3).
  5. Lay the next sheet (3) with the overlap crown lapping the male crown of the first sheet (1).

 

Fix the sheet through the valley or crown at every purlin except the top one using a suitable fixing.

 

  1. The side laps can be sealed at 400mm centres with either a rivet or self-drilling fixing dependent on the profile and site situation.
  2. Apply 2 runs of butyl sealant along the top of the third sheet (3) and one run down the top of the underlap crown for the full length of the lap. Ensure that the sealant laps the run on the underlap crown of the sheet (diagram 4). Both surfaces receiving the sealant should be clean and dry to aid adhesion and at joints the sealant must be overlapped by a minimum of 25mm not butted together.
  3. Lay the next sheet (4) with its overlap crown lapping the underlap crown of the second sheet (2) and its tail lapping the head of the third sheet (3). Fix the sheet through the valley or crown (see manufacturer for details) at every purlin using a suitable fixing.
  4. The side laps can be sealed at 400mm centres with either a rivet or self-drilling fixing dependent on the profile and site situation.
  5. Continue to lay the sheets across the roof continually checking the alignment of the sheets and correcting / adjusting any deviations as necessary.

 

Walls – Laying Sequence

  1. Set the first sheet upright against the framing / purlins at the corner of the building with the first sheets overlap edge to the corner of the building. Ensure that the profile is straight using a plumb line or laser level.
  2. Fix the sheet through the valley or crown at every purlin / support using a suitable fixing.
  3. If necessary (see manufacturer for details) apply a strip of butyl sealant along the top of the underlap crown, both surfaces receiving the sealant should be clean and dry to aid adhesion and at joints the sealant must be overlapped by a minimum of 25mm not butted together.
  4. Set the second sheet with its overlap edge lapping the underlap edge and ensure sheet is upright.
  5. Fix the sheet through the valley or crown at every purlin / support using a suitable fixing.
  6. The side laps can be sealed at 400mm centres with either a rivet or self drilling fixing (see manufacturer for details) dependent on the profile and site situation.
  7. Continue to lay the sheets across the length of the wall continually checking the alignment of the sheets and correcting / adjusting any deviations as necessary.

 

Cutting Profiles & Post Installation

When profiles have to be cut on site you should use electric nibblers a reciprocating saw or circular saw, the use of grinders or abrasive wheels is strongly recommended against as it more often than not will damage the sheeting. The profile should be supported along the full length / width of the cut and you should protect the finish of any pre coated materials. Once cut all swarf and debris should be immediately removed and cleaned and where appropriate some form of edge protection to minimize future corrosion.

When the project has been completed and all the sheets have been installed you should check that all the fixings are correctly fitted and tightened and that the fixings have not distorted the profile. All fixings should have a protective cap or moulded head to minimize corrosion and any minor scratches have been fully treated. Finally ensure that the roof and walls are free from any swarf and debris.

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