Summary of Trusteel Survey Report Rykneld Homes

This summary describes work commissioned by Rykneld Homes. The survey was carried out by Michael Dyson Associates Limited over the period 6 th September to 10 th November 2011. Date: 18 11 2011 © Michael Dyson Associates Ltd The copyright of this report and any supplementary information issued to the client shall remain vested in Michael Dyson Associates Limited. It shall not be reproduced or passed to any other party without the express written consent of an authorised director of Michael Dyson Associates Limited. Executive Summary The present inspection of Trusteel non traditional properties seeks to establish the structural condition of the properties and recommends appropriate repairs to maintain 30 year assured life structural integrity. Trusteel properties are of steel frame construction clad externally with brick but are not a designated defective property type within the meaning of the 1985 Housing Act (Housing Defects Legislation). The survey covers one property in every pair or half-pair of properties owned by North East Derbyshire District Council. The structural condition of properties in the present survey was derived from a visual survey of external elevations and intrusive inspection of steel frame elements of a representative sample of 136 Nr properties. The survey has confirmed that corrosion of stanchion bases is widespread across the Trusteel properties inspected, but is largely confound to the immediate area above ground floor level where mortar and builders debris has trapped moisture. Elsewhere, stanchions, horizontal and diagonal bracing, internal roof and first floor structures are largely in sound corrosion free condition at present with original paint treatments intact, where observed. Steel angle lintel edges have however corroded where these are exposed to the elements. The external brickwork cladding has been repointed in areas at some properties on a somewhat ad hoc basis. Step cracking is also evident at many properties. Mortar has been found to be weathered and soft, particularly at properties at the Clay Cross site. The brickwork cladding is likely to be porous and water ingress into the cavity will accelerate corrosion of stanchion bases if left unchecked. Ties restraining the brick cladding are deficient in number and where observed were found to be corroded. Brickwork claddings may therefore be at risk of detachment in high winds. Fire stop party divide walls within roof spaces are generally inadequate, with gaps observed to the underside of roof coverings and holes within the walls observed at the majority of inspected properties. Ventilation to roof spaces and levels of loft insulation are also deficient at many properties. The recommended repairs to achieve a further 30 years assured life include a combination of remedial repairs and overcladding the external envelope of the properties. The survey, by including every Trusteel block structure has enabled an order of priority in which recommended repairs should be undertaken to be established. M Dyson -Trusteels Report November 2011 (Summary Jan 2012) 1. Introduction Michael Dyson Associates Limited was appointed by Rykneld Homes to undertake a Survey Appraisal of its stock of Trusteel non-traditional houses by means of a visual and intrusive survey. The term “non-traditional” generally refers to prefabricated building systems, frames and construction methods that are significantly different from those used for more traditional masonry construction. The Trusteel properties are of prefabricated steel frame construction, clad externally with brick and lined internally with plasterboard and wood wool slabs. The Trusteel properties are not a designated defective property type within the meaning of the 1985 Housing Defects Act., however the non traditional construction and the potential for corrosion and structural deterioration of these properties can lead to difficulties in obtaining mortgages for residents wishing to exercise their right to buy. Information provided by Rykneld Homes at the outset indicated that the stock of Trusteel non-traditional properties included a total of 213 Nr houses at three different sites, with a similar number of privately owned properties as follows: Location Rykneld Homes Privately Owned Total Clay Cross 149 137 286 Wingerworth 60 64 124 Grassmoor 4 2 6 Totals 213 203 416 The survey included a detailed invasive assessment of 136 Nr Trusteel properties selected by Rykneld Homes at the outset of the survey. Only the properties owned by North East Derbyshire District Council are included within the survey, although it is understood that a summary of the results will be made available to private owners and North East Derbyshire District Council would encourage owners to undertake the recommended repairs and reinstatement works to the Trusteel properties. The cost of any such surveys repairs and reinstatements will be the responsibility of each private owner. The objectives of the structural investigation include: • Assess (by visual and invasive investigation) the existing condition of the structures. • Establish repair works required at each structure and order in which repairs should be implemented. 2. Survey Methodology A detailed investigation of the 136 Nr properties selected for survey by Rykneld Homes was carried out including:- • Examination of general condition of the external fabric, particularly those parts of the envelope likely to deteriorate to the point of requiring repair or replacement during the next 30 years. • Visual inspection of the internal aspects of the dwellings and examine the structure in the roof space. • Inspection of present condition and adequacy of party fire stop wall within the roof space. • Establish the construction of the first floor (void properties only). • Removal of small areas of masonry from external walls to enable inspection of the lower sections of the steel frame, particularly at the corners of the property. 3. Results of Survey 3.1 Construction Details Typical Trusteel House Front Elevation Typical Trusteel House Rear Elevation 3.2 Stock Distribution The address list provided by Rykneld Homes Limited included a total of 213 Nr North East Derbyshire District Council owned Trusteel properties located at 3 Nr sites at Clay Cross, Grassmoor and Wingerworth, Chesterfield. The properties are believed to have been built in the period 1946-1966 and are all of semi-detached 2-storey houses with a 3-bedroomed layout. In addition to the North East Derbyshire District Council owned Trusteel properties there are a large number of privately-owned Trusteel properties distributed across the 3 Nr sites. 3.3 General Property Condition and Repairs History Information provided by Rykneld Homes indicated that the properties are in generally original structural condition and have not benefited from any significant programme of improvements other than routine repairs and maintenance and replacement of doors and windows. The findings of the survey showed that whilst there was relatively little evidence of deterioration of external brick cladding and few significant structural defects were noted internally, the invasive investigation of external walls identified varying levels of corrosion of steel stanchion bases, both from property to property and from elevation to elevation at individual properties. Stanchions and bracing were observed to exhibit M Dyson -Trusteels Report November 2011 (Summary Jan 2012) slight surface corrosion and deterioration of the original red oxide paint treatment, which had advanced in many instances to include loss of section immediately above base level. The external brick skin was noted be attached to stanchions by wire half triangle type cleats. These were found to be generally insufficient in number by present standards, and suffering from a degree of corrosion. Inspection of roof spaces highlighted significant gaps to party wall fire stops at a number of properties. The report recommends as a minimum a combination of repairs and maintenance to ensure continued affective weather tightness, adequate levels of heating and ventilation to ensure that the steel frame structures are kept warm and dry, with low internal humidity levels, debris in cavity bases is removed and any corrosion of steel stanchions and exposed lintel edges is treated appropriately, that fixity of external brick cladding is improved, and that all party wall fire stops are made adequate. In order to improve levels of thermal performance a system of external wall insulation and render overcladding was recommended. Given the extent of corrosion observed at the base level of stanchions at properties included in the previous survey, it was recommended that the repairs be implemented as soon as practicable and within the next 3 years of the repairs programme. 3.4 Present Condition A total of 136 Nr Trusteel properties were investigated in detail as part of the survey, including 92 Nr properties from the Clay Cross site, 3 Nr Properties from the Grassmoor site and 41 Nr properties from the Wingerworth site. The surveyed properties represent a high percentage of the stock of Trusteel properties owned by North East Derbyshire District Council. External Visual Inspection The visual inspections of accessible external elevations of the Trusteel properties selected for survey identified relatively little deterioration of the external brick cladding or of defects to roof finishes. The steel frame structural elements are however hidden from direct observation. Corrosion of lightweight lattice steel

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