BRENTFORD TOWERS, GREEN DRAGON LANE External refurbishment and associated works.

Tender description

The London Borough of Hounslow wish contractors to carry out the external refurbishment of all of the 6 high rise blocks at the Brentford Towers Estate and which will comprise: - • the provision of a fully designed access scaffolding and protection to external facades of all elevations to the full height to roof and parapet levels. It is noted that basement areas, ramps, landscaped areas, culverts, drains etc are in the vicinity of the ground levels to each block. Emergency including fire, and safe access for members of the public, contractors, refuse collections etc are to be maintained at all times to the perimeter of the blocks and all existing entrance points to fire exists, bin stores and main entrances at both ground and mezzanine levels. • the provision of specialist surveys and reports to fully ascertain the condition of all existing concrete surfaces to external wall panels, balconies, parapets, floor constructions, internal wall panels etc. This includes but is not limited to hammer testing, cover meter surveys, carbonation and concrete analysis, penetration testing for corrosion inhibitors, pull out testing for supplementary fixings and inspections of panel joints. • Additional surveys and reports are also to be undertaken of each tower to fully determine the risk for disproportional collapse in the event of accidental loading, and to agree to what extent structural remedial works will be required. This will include inspections within void and occupied dwellings to undertake opening up works, cover meter surveys and the like as agreed with Employer. • The full measure of concrete repairs will be undertaken to all existing exposed concrete surfaces to all blocks comprising plain vertically ribbed external wall panels, aggregate faced spandrel panels, in-situ concrete to balcony upstands and soffits, parapets, columns and the like. This will be on the basis of a full Corrosion Management System (SIKA) to BS EN 1504 with the provision on completion of a 15 year works and materials guarantee against future corrosion, concrete degradation and further spalling. • Post survey works will comprise the preparation of existing surfaces, including high pressure water jetting (noting dry grit blasting will not be permitted), removing areas of cracked and delaminated concrete, the preparation of repair areas, removal of corrosion from exposed reinforcement and the provision of any additional reinforcement, provision of proprietary products for reinforcement protection, bonding primers, concrete repair mortars, spray applied or pelleted Corrosion Management inhibitors, and anti-carbonation protective coatings including all appropriate smoothing coats, pore sealers and primers. • Structural remedial works may be required to provide additional ties to the existing outer wall panels back to the internal panels, vertical and lateral restraint fixings, trusses and steelwork to restrain wall panels and floor slabs as directed by Building Contr