Visual Inspection
Our study included a visual inspection of the building and a photographic record is included in the appendices. From our inspection, the building appeared to be in sound condition with no obvious signs of structural deterioration or defects that would affect the over-cladding works. The existing cladding units on the surface appear to be in reasonable condition. However, on closer inspection it is evident that the galvanised steel and foam insulation has begun to break down with age. The existing aluminium windows remain serviceable. However, they are single glazed and therefore no longer provide the level of thermal insulation required by current building regulations. The roof structure is in sound condition and has recently undergone refurbishment.
Open up Works - Trial Pits
In order to establish the details of the existing foundations and extent of the undercroft, a trial pit investigation was carried out on the 24th January 2006. The excavations revealed that the undercroft consists of a 200mm reinforced concrete wall sitting on a 300mm thick base slab. The construction has been built onto a blinding concrete approximately 150mm thick as shown in the appendices. (Please refer to Appendix E for sectional drawing)
Based on the results of the trial pits, we carried out some outline scheme design to establish the percentage increase on the existing foundations if a new skin of face brickwork was constructed. Our analysis showed that the load increase for a single storey height of face brickwork would be around 8% which would be an acceptable increase without strengthening the foundations. The two storey brickwork showed an increase of 16% and this would require strengthening works to the foundations.
Open up Works - Steel Frame
No investigation was conducted to determine the condition of the embedded steel frame elements which would require dismantling the existing cladding. There were, however, no signs of any corrosion staining or movement of the frame on the existing cladding and we would expect the steelwork to be in serviceable condition. At this stage we would suggest that some local opening up work is undertaken during the detailed design, but in the meantime some allowance for localised repairs to base plates have been included in the cost plan.
The over-cladding systems being considered will require support from the existing frame. At this stage, we have not carried out any detailed design on the capacity of the existing steel frame to support the new over-cladding as this is beyond the brief of our current scope of work. However, we have, studied the standard details made available and assuming that they are correct, we do not anticipate their will be any requirement for additional strengthening works. In support of this, the overcladding works carried out to William Parker School, by Structherm, did not require any additional strengthening works. Despite this, as a precaution, an allowance for localised strengthening works has been included for in the cost plan.
©2004 Oxford Method Royalties Management Group