Architects
Swish cellular PVC fascia, soffit, guttering and cladding systems; used by architects to create attractive, affordable designs that meet client expectations and are simple for contractors to install.
Design
Use the tools below to see how the roofline comes together, check on the Building Regulation requirements and access CAD drawings to set out the required design.
Roofline assembler
The Swish Visual Assembler is an animated representation of the major roofline components. It shows their relationship to each other and how they fit together.
Notes
- Fascia boards are available in a large number of colours, styles and sizes to suit most applications.
- Ventilation may be provided over the fascia or through the soffit (alternatives not shown).
- For 16mm to 25mm fascias a backing board is not required.
- Guttering fixes directly to these fascias.
- Fascia & soffit joints are made between rafters.
- 8mm expansion gaps required at joints in long runs.
- A4 marine grade stainless steel fixings required.
Design Guides
A series of A4 leaflets setting out the important design and installation considerations for all the major roofline, cladding and gutter components
| 1. Jumbo & 16mm Fascias.pdf | 129.15 kB | ![]() |
| 2. Capping Fascias 9mm.pdf | 125.49 kB | ![]() |
| 3. Bargeboards.pdf | 140.26 kB | ![]() |

Ventilation at the Eaves
Roof voids must be ventilated in order to stop warm air condensing on cold surfaces. Condensation encourages rot and mould growth. The gap dimensions shown on the drawings are the minimum widths required for clear continuous air paths.

*Duo pitch roofs greater than 200 pitch or greater than 10m span should have additional ventilation at the ridge to assist airflow through the roof void, equivalent to at least a 3 mm wide continuous gap. Additionally, if the span is greater than 10m the overall ventilation area should be increased to at least 0.6% of the total roof area.
**Air paths should not be obstructed. A minimum 50mm free air path should be maintained between the top of the insulation and the underside of the roof decking.
Ventilators
Swish ventilators for roof voids are covered by British Board of Agrément Certificate No.91/2620. When used in accordance with the Certificate, Swish ventilators will satisfy the following statutory requirements.
England and Wales
The Building Regulations 2000 (as amended) (England and Wales):
Requirement C2 (a) (b) (c): Resistance to Moisture
Regulation 7: Materials and workmanship.
Scotland
The Building (Scotland) Regulations 2004: (as amended)
Regulation 8: (1) (2) Fitness and durability of materials and workmanship
Regulation 9: Building Standards – Construction; Standard 3.10 – Precipitation and Standard 3.15 - Condensation
Northern Ireland
The Building Regulations (Northern Ireland) 2000, Regulation B2; (as amended)
Fitness of materials and workmanship, C4: (b) Resistance to ground moisture and weather and C5: Condensation.
Swish ventilators also meet the recommendations BS 5250: 2002 which deals comprehensively with the subject of condensation in dwellings.
CAD Library
A library of DXF & DWG drawings of individual profiles and typical installed situations. This library is accessed through the Fastrackcad website
Downloading
These CAD drawings may be opened and downloaded to a PC that supports any DXF or DWG based CAD software.
View Files
Files can also be viewed on a PC without CAD sofware by visiting the links above and downloading the viewer software as indicated.
Technical Help
Swish is happy to offer technical help for design and installation requirements:
- Tel: 01827 317238
- Fax: 01827 317201
- Email: technical@swishbp.co.uk
Swish offers the following:
- Product training for specifiers
- Onsite installation training for contractors
- CPD presentations - in person or on line.
CSH (Code for Sustainable Homes)

The Green Guide, which underpins the Materials section of the Code for Sustainable Homes, confirms the strong contribution that PVC building products make towards sustainable construction.
By referring to the Green Guide (www.greenguide.org.uk), specifiers and contractors will find that PVC Roofline and Cladding products from Swish can help them achieve maximum material points under the Code for Sustainable Homes.
Roofline
Swish Cellular PVC roofline products qualify for 3 points as a Tier 1 product under the section dealing with Responsible Sourcing of Finishing Elements (Mat3).
Cladding
PVC Cladding installed over timber framing carries an A+ rating. This allows developers to claim the maximum three points available under the CSH for just such an external wall system (Mat1). In addition, under Responsible Sourcing of Basic Building Elements (Mat2), Swish PVC Cladding qualifies for 3 points as a Tier 1 product.
Note
Tier 1 products in PVC are those where the manufacturer has obtained BES6001 Responsible Sourcing Certification.
Specification
For guidance on specification of Swish Roofline, Cladding or Guttering please call 01827 317238.
Full technical design and installation guides are available.
Swish CPD
Swish provides RIBA approved CPD seminars in closed sessions and at established trade shows. In addition the latest Swish CPD is now available to view below.
The document is best viewed by selecting the Fullscreen mode (in blue below). At the bottom left of the document ensure that the SLIDE option is selected, and move through the presentation using the arrows at the bottom centre of the document.
Cellular PVC, technical aspects of fascia and soffit installation, and the environmental advantages of PVC specification.
- PVC materials
- The material challenge at the roofline
- Installing PVC roofline
- The Code for Sustainable homes
- Sustainability of cellular PVC
Roofline CPD presentation lasting approximately 30-40 minutes
Literature
The Swish literature library is designed to provide architects with full technical information. We have selected the most appropriate publications below for range detail and specification information.
Click on an image to open a document.
Range Guides
| 1. Swish Range Guide Oct 2010.pdf | 2.25 MB | ![]() |
| 2. Swish Rainwater_Bro_0510.pdf | 402.35 kB | ![]() |
| 3. M-Boss_Bro_Roofline.pdf | 2.86 MB | ![]() |
Installation Guides
Certificates
| 1-Swish BES6001 Responsible Sourcing Certificate.pdf | 273.43 kB | 15-08-2011 11:18 | ![]() |
| 2-Swish-BP-ISO-9001 Certificate.pdf | 446.59 kB | 15-08-2011 11:18 | ![]() |
| 3-Swish-ISO-14001 Certificate.pdf | 255.26 kB | 15-08-2011 11:19 | ![]() |
| 4-Swish-OHSAS-18001 Certificate.pdf | 287.07 kB | 15-08-2011 11:19 | ![]() |
| 5-Swish-Kitemark-Licence.pdf | 589.99 kB | 15-08-2011 11:19 | ![]() |
| 6-Swish-Cladding-BBA-Certificate.pdf | 524.51 kB | 15-08-2011 11:19 | ![]() |
| 7-Swish-Roofline-BBA-Certificate.pdf | 218.3 kB | 15-08-2011 11:19 | ![]() |
Guarantees
| 1. Swish 20 Year White Guarantee.pdf | 65.89 kB | ![]() |
| 2. Swish 10 Year Foil Guarantee.pdf | 71.67 kB | ![]() |
| 3. Swish 10 Year Colour Guarantee.pdf | 39.89 kB | ![]() |
Environmental
The roofline and clad fascades of any dwelling are usually:
- Exposed to the elements
- Inaccessible for regular maintenence
- Difficult and costly to access and maintain
Where timber is used::
- It generally has a high moisture content
- Is maintained with short lifetime coatings
- Is inadequately maintained above the fasca, around the gutter and at the joints
- CO2 and VOC's are created during the maintenence process
- The material is unlikely to last more than 20 to 30 years
- Difficult to recycle at the end of its service life.



