Search results

Deals with the specification and repair of stone slate roofing within the Yorkshire Dales National Park. Initially examines the importance of roofing works and then goes on to give advice on preliminary items of access and safety. The methods of re‐slating are then discussed and specific techniques of details are considered and illustrated. The surveying of stone slate roofs has been the subject of a previous paper.

This is an initial attempt to classify natural roofing slate quality using the new European Standard BS EN 12326 and suggest how such classification may be employed to predict in‐service performance and identify potentially problematic materials.

A wide range of natural roofing slates has been subjected to the new standard testing regime and additional tests carried out. Experience of known in‐service performance and previous test results have also been taken into consideration.

An initial classification of natural roofing slate quality has been proposed with the flexural strength, water absorption, potential for oxidation and carbonate content considered to be the key components.

There is considerable scope for refinement of the proposed classification by investigating the performance of the wide range of other natural roofing slates available and taking the results into consideration. Predicted in‐service performance is based on practical experience and can be considered only a general guide.

By classifying natural roofing slate quality users will be able to make better informed purchasing decisions based on cost versus quality. Slate producers, especially those with higher quality slates, will also be able to market their materials accordingly with less chance of losing out to lower quality, potentially problematic materials that still conform to the new standard.

The concept of a quality classification for natural roofing slate is not new, but this has been omitted during the creation of the new standard. The proposed classification is broader and probably better defined than those in existence elsewhere or previously used within the European Union member states.

This paper describes the development of a novel automated vision system used to detect the visual defects on painted slates.

The vision system that has been developed consists of two major components covering the opto‐mechanical and algorithmical aspects of the system. The first component addresses issues including the mechanical implementation and interfacing the inspection system with the development of a fast image processing procedure able to identify visual defects present on the slate surface.

The inspection system was developed on 400 slates to determine the threshold settings that give the best trade‐off between no false positive triggers and correct defect identification. The developed system was tested on more than 300 fresh slates and the success rate for correct identification of acceptable and defective slates was 99.32 per cent for defect free slates based on 148 samples and 96.91 per cent for defective slates based on 162 samples.

The experimental data indicates that automating the inspection of painted slates can be achieved and installation in a factory is a realistic target. Testing the devised inspection system in a factory‐type environment was an important part of the development process as this enabled us to develop the mechanical system and the image processing algorithm able to perform slate inspection in an industrial environment. The overall performance of the system indicates that the proposed solution can be considered as a replacement for the existing manual inspection system.

The development of a real‐time automated system for inspecting painted slates proved to be a difficult task since the slate surface is dark coloured, glossy, has depth profile non‐uniformities and is being transported at high speeds on a conveyor. In order to address these issues, the system described in this paper proposed a number of novel solutions including the illumination set‐up and the development of multi‐component image‐processing inspection algorithm.

Examines modern roof coverings and their associated problems over the past decade. Discusses the designers’ and suppliers’ dependence on and compliance with British Standards. Provides details of the problems and their technical solutions.

This paper considers vernacular roofing practices for natural slate within the Lake District National Park and looks at the application of traditional techniques within the environmentally‐sensitive area. The paper examines the geology of the Lake District, slate production, methods of re‐slating and specific techniques and details. The paper uses case studies of recent roofing projects to illustrate good practice.

States that networking theories have attracted increasing attention during the 1990s – although the network concept is certainly not new. Looks at the computer industry in Silicone Valley, California and the textile industry in Prato, central Italy. Discusses co‐operative behaviour and the relative advantages derived from such arrangements. Examines the slate industry in North Wales and, specifically, the decision by six long‐established slate quarries to come together to market their common product and promote Welsh slate at a global level. Aims to look at the industry’s past, present and future trends discovering how this inter‐firm collaboration aims to turn around the plight of industry.

Deals with the surveying of stone slate roofs within the Yorkshire Dales National Park. Initially examines the history of stone slating in the area and then identifies problems today due to lack of new materials and loss of craft techniques. Gives practical advice on the surveying of the roof coverings and preliminary guidance on preparation and equipment. This is then followed by a standard format approach to the survey dealing with the coverings, ridge, verge and other details, followed by the internal inspection and condition of the slates, battens and fixings. Discusses costings and concludes that a standard format is the most suitable and that the building professional should be aware of regional variations when working with the material. Detailed surveys of the roof will allow repairs and replacement to be specified confidently.

Opens with a discussion as to whether the ′real thing′ is necessarily better than the ′cheaper alternatives′, and traces the historic rise of alternatives to ′real′ building products. Reviews available substitutes for both slating (i.e. not slate) and tiling (defined as not a tile made from clay). Discusses life expectancy and planning restrictions on substitute products.

Proposes that simulations teach timing and balance which is not possible to teach in a traditional manner through classrooms, books or films. States that these can be used to increase the power of the organization if they are used correctly. Proceeds to explain four stages, or slates of simulation deployment used today. Concludes that although simulations take more work, they result in exponentially better results.

The paper seeks to deal with vernacular roofing practices within the North York Moors National Park.

Initially the paper carries out a literature review of the geography and geology of the area and identifies what makes it physically unique. The paper then examines the development of various roofing materials, including thatch, stone slates and pantiles with case studies of old practice and modern methods from around the Park.

Roofing styles are simplistic and have steered away from the intricate in favour of the indigenous or readily available. The paper demonstrates the much‐regionalised nature of the roofing materials and recognises this as one of the special cultural features worthy of conservation.

The results are limited to the North York Moors National Park but the approach taken could be extended to other conservation areas.

The results of the research will benefit those involved in the conservation of vernacular buildings in the North York Moors National Park.

The paper calls for additional guidance for roofers and specifiers on traditional vernacular techniques and for existing funding under the Environmental Stewardship Scheme to be extended to include rural communities in National Parks.