GRIMSBY ICE FACTORY STRUCTURAL REPORT

Appraisal of Existing Structure

(70 pages) by Alan Baxter & Associates LLP, with Richard Griffiths Architects,and KMCS (Cost Consultant) 
Prepared by David Johncox, John Woodcock and Colin Hayward.

The report , commissioned by North East Lincolnshire Council, gives an outline of the scale and cost of works to put the building in a stable and weather-proof state before any alteration can made for re-use. Before proposals for tenders could be drawn up, an enabling contract would be required to carry out exploratory work and carry out trial repairs for agreement with English Heritage.

The report notes the history and geology of the Grade II* listed Ice Factory before considering the internal structure. It notes that The Ice Factory comprises two main buildings built in 1900/1901 and 1907/1910 and that there is a small 1950s extension to the first building.

Although a typical industrial structure of brick walls and steel columns supporting steel and timber roofs and floors, the form is unique to the purpose of large-scale ice-making for the fishing industry. In places the structure of building forms part of structure to the ice-making machines. The original design and construction is thought to be of above average quality producing a robust structure.

The large buildings are irregular -some areas extend below ground level, some spaces have a full 10m clear height. Others comprise three storeys – two storeys of ice making over an undercroft for the distribution of services. Alterations to the structure do not appear to have been of major significance.

Although the foundations generally appear sound, cracks in the corner wall of the 1907/1910 building suggest differential settlement of the foundation. It seems likely, although not proven, that the foundations are supported on timber piles.

There has been a lack of maintenance – probably well over the 20 years since it closed. The Ice factory has missed two of the major overhauls usual for the lifecycle of an industrial building. Rainwater cascades through the buildings from top to bottom. The structure is now in a poor state, not just due to lack of maintenance but also because the ice-making environment involved large volumes of water moving around the building. It is degrading at a rapidly increasing rate.

The report describes likely remedial works in accordance with the Scope of Works set out by NELC.

The structure of the buildings can be retained though extensive repair and improvements required.

A Conservation Statement is required to help understand what is historically important about these buildings, and to establish a clear and proper interpretation of their cultural value.

The flat roofed areas can probably be used to support some new lightweight plant.

The brickwork walls are generally robust and with the ice making process removed, they could be used to support some significant new imposed loads from additional floors.

It may be possible to replace the existing very heavy duty floor structures in the tank rooms with several new lighter weight floor structures. In the areas where there are no internal upper floors, e.g. original condenser room, boiler house and the 1907/1910 store, it is likely that the existing structure could support one or maybe two new floors.

Remedial Work Required

  • External Walls:
    All cracks in brickwork need to be made good from both sides (inside and outside).Where cracks result from corroded steelwork, the steel must be thoroughly brushed, cleaned, and painted prior to making good the brickwork. Some steelwork may need repair.
  • Roof Structure:
    It is a priority to keep the weather out by replacing the roof . First with temporary scaffold roof structure which would deflect the rainwater away from the building. This should be followed by replacing the flat roofed areas on top of the existing steel beams and replacing the small pitched roof over the original 1900/1901 office. The report states the multi pitched roof over the store in the 1907/1910 building could be refurbished.The pitched roofs over the old boiler house, and the tank rooms appear to be in better condition than the others and the report suggests removing and separating all the roof coverings into those which can be re-used (say 30%) and those which cannot.
  • Internal Structure:
    Allow 18 months to dry out, clear out all the debris, remove all rotten/damaged timber boarding. Pump out all the water from the trenches and undercrofts. Replace corroded steel columns or perhaps encase in reinforced concrete to maintain their structural function. This applies to some if not all of the columns in the undercroft beneath the original 1990/1901 tank rooms.A number of cost issues are dependent upon the opinion of English Heritage on the approach to the repairs. These cannot be progressed until the Conservation management Statement is completed and a proposal submitted.
  • Internal floors:
    The ice making machinery would need to be covered or removed prior to installing new floors. Repair of the existing steel frame and supporting structures may require reoval of the ice making equipment. The report also considers the iconic conveyor belts which connect the Ice Factory to the fish shed next to number 2 dock and asks if these are to be retained?

Estimated Costs

The basic estimated cost for the likely works by the Quantity Surveyor, KMCS of the three options discussed with NELC are:

  • (C) To bring the buildings to a re-usable standard £4.75M
  • (B) A reduced version of (C) £3.5M
  • (A) Temporary Protection with some Urgent Structural Repairs £1.5M

The Cost report considered three alternatives.

  • A: Temporary fix to make the building safe and watertight, prevent further deterioration and allow further surveys.
  • B: Minimal repair and renewal.
  • C: Full Extensive repair and upgrading of structure and external envelope of the building.

Although costs are given as a guide, actual costs depend on full and proper surveys, agreement on the work, specifications and procurement. Costs are given at 2010 levels with no allowance for inflation. It is also noted that costs will increase as further deterioration sets in.

Although phased work is possible this will increase costs due to reduced scale of work making tendering less attractive, increased site organisation costs and inflation over extended period.

Quoted costs exclude fees (possibly 18%), survey costs (including conservation survey costs) estimated at £150,000.

Site acquisition and finance charges. Repair, restoration or removal of original machinery.

When preparing costs the report notes that there will be a substantial cost in the Contactor establishing his set up on site . £80,000 for the six months estimated for Temporary Works and £210,000 for 12 months on the more detailed options.

Budget Cost Appraisal

Option A: Temporary Works
£1,516,000. 1910 extension 498,000 original building 1,018,000.
(Costs of site organisation are lower because only six months is estimated.)

Option B: Minimum repair of Structure and Envelope
£3,691,00 1910 extension £1,239,000 Original Building £2,453,000.

Option C: Full repair and Upgrading Structure and Envelope
£4,750, 000. 1910 extension £1,693,000 Original Building £3,057,000. However, if the existing timber floors are to be replaced by concrete (rather than new timber) floors there may be additional cost. Estimate of £8,000 to clean and disinfect pigeon droppings.