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Ice Factory, GrimsbyAppraisal of Existing Structureby Alan Baxter & Associates LLPwith Richard Griffiths Architectsand KMCS (Cost Consultant)February 2010

Alan Baxter

Ice Factory, GrimsbyAppraisal of Existing Structureby Alan Baxter & Associates LLPwith Richard Griffiths Architectsand KMCS (Cost Consultant)February 2010

Alan Baxter

Contents1.0 Summary..........................................................................................................1

2.0 Introduction....................................................................................................2

3.0 HistoryoftheBuildingandtheSite......................................................3

4.0 Geology............................................................................................................5

5.0 FormofExistingStructure........................................................................7

6.0 ObviousDefectsintheExistingStructure....................................... 13

7.0 ProposalsforRemedialWorkstotheExistingStructure........... 19

8.0 ProposedAlterationstotheStructure.............................................. 22

9.0 NextStage.................................................................................................... 23

10.0 ExistingFabric,byRichardGriffithsArchitects(RGA)................. 24

11.0 CostEstimate,byKMCS.......................................................................... 25

Appendices............................................................................................................. 27

AppendixA–InformationReceived........................................................................... 28

AppendixB–DrawingsbyABA.................................................................................... 29

AppendixC–DrawingsbyRGA.................................................................................... 30

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Ice Factory, Grimsby Appraisal of Existing Structure / February 2010Alan Baxter

1.7 Thesebuildingshavenotbeenmaintainedinanyformformanyyears,probablywellinexcessofthe20yearssincetheyfellintodisuse.Rainwateriscascadingthroughthebuildingsfromtoptobottom.

1.8 Overall,andmostlyasaresultofthetotallackofmaintenance,combinedwiththeaggressiveenvironmentcreatedinthebuildingsfromthemanufactureoficeinvolvinghugevolumesofwatermovingaroundthebuildings,thestructureisnowinaverypoorstateindeed.

1.9 Intermsofanormallifecycleforbuildingsofthisnature,thesebuildingshavemissedtheirlasttwomajoroverhaulsandarenowdegradingatarapidlyincreasingrate.

1.10 Thefollowingnotesdescribetheaboveingreaterdetailtogetherwithproposalsforthelikelyremedialworksrequiredtotrytoaddresstheobviousdefectsinthestructure,allinaccordancewiththeScopeofWorkssetoutbytheNELC.

1.11 Itdoesappearasifthebasicstructuretothebuildingscanbemostlyretainedthoughthereissomeextensiverepairandimprovementsrequired.

1.12 AConservationStatementisrequiredtocomplementthisstudyandhelptounderstandwhatishistoricallyimportantaboutthesebuildings,andtoestablishaclearandproperinterpretationoftheirculturalvalue.

1.13 ReferalsotothelatersectionsonthefabricofthebuildingbytheArchitect,RichardGriffithsArchitects,andthecostestimatesforthelikelyworksbytheQuantitySurveyor,KMCS.

1.14 ThebasicestimatedcostbyKMCSofthethreeoptionsdiscussedwithNELCare:

(C) Tobringthebuildingstoare-usablestandard £4.75M

(B) Areducedversionof(C) £3.5M

(A) TemporaryProtectionwithsomeUrgentStructuralRepairs £1.5M

RefertoSection11.0forfurthercostinformation.

1.0Summary Structure

1.1 TheIceFactorycomprisestwomainbuildingsbuiltin1900/1901and1907/1910.Thereisasmall1950sextensiontothefirstbuilding.ThebuildingsareListedGradeII*.

1.2 Thestructuretothesebuildingsistypicalofindustrialbuildingsoftheirtimewithloadbearingbrickworkwallsandinternalsteelcolumnssupportingsteelandtimberroofsandfloors.

Theformofthestructure,however,isveryparticulartothepurposeofthebuildings,thatis,tomanufactureverylargepiecesoficeforthefishingindustry.

Inplacesthestructuretothebuildingformsapartofthestructuretothemachine/workingsoftheicemakingprocess.

1.3 Thebuildingsarelargeandaretypicallyaround10mhighwithsomeareasextendingalittlebelowgroundlevel.Somespaceshaveafull10mclearheightandotherscompriseofthreestoreys,e.g.twostoreysoficemakingoveranundercroftforthedistributionofservices.

1.4 Itappearsthattheoriginaldesignandconstructionofthestructurewasofareasonablequalityproducingsomerobuststructures,necessaryfortheheavydutymanufacturingprocesscarriedoutwithinthebuildings.

1.5 Thefoundationsgenerallyappeartohaveperformedwelltodatealthoughinonecornerofthe1907/1910buildingthepatternofcrackinginthebrickworkwallsuggeststheremayhavebeensomedifferentialsettlementofthefoundation.Atpresentlittleisknownabouttheformofthefoundations,thoughgiventhepoorgroundconditionsillustratedonthelocalgeologymapsandboreholesobtainedfromtheBritishGeologicalSocietyitseemslikelythefoundationsaresupportedontimberpiles.

1.6 Astheicemakingprocesshasdevelopedthroughouttheworkinglifeofthesebuildingstherehasbeenaneedforsomealterationstothestructurethoughthesedonotappeartohavebeenofmajorstructuralsignificance.

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2 Ice Factory, Grimsby Appraisal of Existing Structure / February 2010 Alan Baxter

2.0Introduction2.1 AlanBaxter&AssociatesLLP(ABA)havebeeninstructed

byNorthEastLincolnshireCouncil(NELC)toleadateamofconsultantstocarryoutanappraisaloftheexistingstructure,allinaccordancewiththesubmissiontoNELCdated26.06.09,theApproachandMethodologysubmittedon30.07.09anddiscussionswithNELCon17.09.09,14.01.10and27.01.10.

2.2 Theothersintheteamofconsultantsare:

RichardGriffithsArchitects(RGA)andKMCS(QuantitySurveyors)

2.3 Thefollowingreportisasummaryofourappraisalandcomprisesthreemainelements:

(i) Structuretothebuilding ByABA

(ii) Fabricofthebuilding ByRGA

(iii) CostEstimateofproposedworks ByKMCS

Itisbasedonourdesktopresearch,togetherwithwhatweareabletoseefromourvisitstothebuildingon17/09/09and14/01/10andtheoutputfromworkshopsheldatABA’sofficeswiththeconsultantteam,andwiththeclient.

2.4 AccesstothebuildinghaskindlybeenprovidedbyAssociatedBritishPorts(ABP)thoughinternallyaccessisseverelyrestrictedduetotheunsafenatureofthefloorstructuresinmanyplaces.

View from Gorton Street

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3.0History of the building and the Site3.1 TheIceFactorycomprisesoftwomainbuildingsseparatedby

arailwayline(nolongerinuseandcoveredover).Themainbuildingtothesouthoftheoldrailwaywasbuiltin1900/1901byTheGrimsbyIceCompanyandwasthelargestofalltheicefactoriesinthetown.

3.2 TheFactorywasextendedin1907/1910withtheconstructionofthebuildingtothenorthoftheoldrailwayline.

3.3 In1930/1933theFactorywasmodernisedwiththeoldsteamdrivenplantreplacedwithelectricitydrivenplant.Thisapparentlyaffectedthemachineryanditsfittingsmorethanitsfabric.Aspartofthisworktheoriginalboilerhousechimneywasdemolishedthoughitsbaseremains.

3.4 Intheearly1950stheoriginalFactorywasextendedtoincorporateanewcompressorroom,togetherwithotheralterationstotheicestores.

3.5 TheIceFactoryclosedin1990andhasnotbeeninusesince.

3.6 ThebuildingswerelistedgradeII*on12September1990.AcopyofthelistingisenclosedinAppendixA.

View from Fish Dock Road Aerial view

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1905Recent aerial photo

TheIceFactory

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4.0Geology4.1 Thegeologymapofthisareashowsthemajorityofthedock

builton‘landslip’overAlluviumoversandsandgravels.

Geology map

TheIceFactory

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4.2 BoreholesobtainedfromtheBritishGeologicalSocietyshowthesitetobeunderlainbymadegroundoversoftsilt,peatandclaywithsomethinlayersofsand,overchalkwhichisfoundaround80ft(24mm)belowgroundlevel.

4.3 NodetailsofthefoundationstotheIceFactoryhavebeenobtained,butitisdocumentedthattheGrimsbyDockTowerbuiltin1851isfoundedontimberpilesprobablydrivenintotheclay.ItseemslikelythattheIceFactoryisalsosupportedontimberpiles.

4.4 Boreholesfrom1925showedadepthtogroundwaterofaround15ft(4.57m),whereasin1950thedepthisshownas21ft(6.4m)andfrom1981adepthofaround10ft(3m)isrecorded.

BGIS Borehole Ref TA21/64A or Ref TA21SE/21A from the Ice Factory engine house

BGIS Borehole location plan

TheIceFactory

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5.0Form of Existing Structure5.1 Thesebuildingscompriseoffairlyconventionallate19thearly

20thCenturyindustrialstructuresformingsuchspacesasaboilerhouse,compressorrooms,switchroomsandofficese.g.areas(i),(iv),(v)and(ix),alltheretosupporttheprincipalpartsofthebuildingwheretheicewasmanufacturedorstored,ieareas(ii),(iii),(vi)andvii).Intheseice-makingareasthestructureformspartofthemachineryusedtomaketheice,andalsosupportsthecasing/envelopetothemachines,ietheroofandwalls.

Key planWatertankonroof

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Nexttothisspaceisthe1950sextensioncomprisingofaswitchroomwithanofficeatfirstfloorlevel,andthenanotherdoublestoreyheightcondenserroom.Thepitchedroofovertheofficeappearstobeoftimberceilingjoistsandrafterssupportedonsteelbeams,andthefirstfloorcomprisesofafillerjoistfloorslabspanningbetweensteelbeams.Thenewcondenserroomroofappearstobeofin-situreinforcedconcreteslabspanningbetweensteelbeams.Thesteelbeamsaresupportedonsteelcolumnsbuiltintothebrickworksidewalls.

Alargewatertankissuspendedabovetheroofoftheoriginalcondenserroomonasteelframewhichspansbetweentheloadbearingwallsatrooflevel.

(i) CompressorHouse,SwitchRoomandOffice:

Theoriginalcompressorhousecomprisesatallsinglestoreyspacearound9metreshigh,withsolidloadbearingbrickwallssupportingsteelroofbeamsandaconcretefillerandsteeljoistflatroof.Thelongerspanningroofbeamsareproppedoff3steelcolumnstowardsonesideoftheroom.Thesecolumnsalsosupportderrickcranesforservicingthecompressorsintheroom.

Thegroundfloorisofsolid,probablyreinforcedconcreteconstructionwithnumerousservicestrenches/pitsincorporatedintotheslab.Itislikelythattheveryheavycondenserplantisfixeddowntothickreinforcedconcreteplinthsaspartoftheslab.

Services trench in ground floor

Typical section through Compressor Room

Water tank on roof

Compressor Room roof

1950s Compressor Room

Original Compressor Room

GableendtoTankRoom

Fillerjoistroofslab

Travellingpulleybeam

RCslabwithpitsandservicetrenches

Derrickcrane

Steelbeam

Steelcolumn

CompressorSection

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(ii) TankRooms:

Thisisthemainpartoftheoriginal1900buildingandcomprisesoftwofloorsoficemakingmachineryoverasemi-basementundercroft,allcontainedwithinanexternalloadbearingbrickwork,andinternalsteelframedstructure.

Accessisseverelylimitedforsafetyreasonswithnoaccessavailabletotheundercroft.

Thestructuretothetwobaybuildingcomprisessteelrooftrussessupportingtimberpurlins,timberboardsandslates,spanningbetweenpiersinthebrickworksidewallsandarowofsteelcolumnsonthelineofthecentralvalley.

Thereisasmallbrickworktowerattheeastendofthetankroomswhichappearstobesupported,inpartoffthesteelframe.

Some equipment remains in Tank Room Internal column support to travelling crane brackets1st floor Tank Room

Typical section through 1900/1901 Tank Rooms

Rooftruss

CIBrackets

Undercroft

Travellingcranebeam

Travellingcranebeam

1stFloor

UpperGroundFloor

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Thetwofloorsoficemakingequipmentaresupportedoffagrillageofsteelbeamsspanningbetweenthesidewalls,thecentralrowofsteelcolumns,andtwofurtherrowsofcolumnsineachbayofthebuildingintheundercroft.

Travellingcranesspanclearacrosseachbayaboveboththetwofloorsoficemakingequipment,supportedoffcastironbracketsattachedtothepiersinthebrickworksidewallsandthecentralrowofsteelcolumns.Thecastironbracketsonthepiersarefixedthroughthebrickworktoexternalplates.

External plates to crane beam brackets

Bracket support to travelling crane beam

View of 1907/1910 Tank Room roof

Roof over Ice Store Original Boiler House

(iii) IceStore:

Thispartofthebuildingcomprisesofathreestoreyexternalloadbearingbrickworkwallsupportingaflatroofofsteelbeamswithprobablyafillerjoistslab.Ithasalsobeenconvertedforicemakingandsocontainstravellingcranesandicemakingequipmentontheuppertwostoreys.Thesemibasement/undercroftiscurrentlyastoreroomfulloffridges/freezersandwasnotaccessible.

(iv) FlakeIcePlant(PreviouslyBoilerHouse):

Thissinglestoreystructurehasloadbearingbrickworkwallssupportingasteeltrussedroofwithtimberpurlins,boardsandslates.

Originallytheboilerhousehadatallbrickchimneyinthenorthernmostcorner,butthiswasremovedaspartofthemodernisationinthe1930s.Itappearsasifthebasetothischimneyremains.

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(v) CondenserRoom/Stores:

Theseareasofthebuildingaregenerallyoftwostoreyswithabasement/undercroft.Accesswasnotpossibletothebasement.Thefloorandroofstructuresappeartobeoffillerjoistconstructionsupportedonsteelbeamssprungbetweenloadbearingbrickwalls.

(vi) TankRooms:

Thisisthemajorpartofthe1907/1910extensionandisofsimilarconstructiontotheoriginaltankroomstructurein5.2(ii)above.

Thebuildingprovidedtwostoreysoficemakingequipmentsupportedbysteelgrillagesatboththefirstfloorandgroundfloorlevels.Travellingcranebeamstothefirstfloorandthegroundfloorarebothsupportedononesidebycastironbracketsinthepierstothesolidloadbearingbrickwallandontheotherbybracketsontosteelcolumns.

Thelowerlevelsteelgrillageissupporteddirectlyoffthereinforcedconcretegroundfloor.Thefloorisformedinsuchawayastoprovidethreetrenchesthefulllengthofthebuilding.

Thereisasmallbrickworktoweratthenorthendofthetankroomwhichappears,atleastinpart,tobesupportoffsteelbeams.

1st floor 1907/1910 Tank Room Ground floor steel grillage Ground floor brench and foundations to brick pier

Typical section 1907/1910 Tank Room and Ice Store

Timbertrusses

Travellingcrane

Travellingcrane

1stfloor

SteelgrillageontopofRCtrenches

Steelbeam

Steelcolumn

IceStore TankRoom

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5.2 Thereisasmallpedestrianbridgebetweenthe1900/1901andthe1907/1910buildingscomprisingofsteelbeamsspanningbetweentheexternalwallsofeachbuildingwithatimberboardeddeck.

5.3 Theseareunusualbuildingswithsomeverylargeopenspacessuchasthestoreinthe1907/1910buildingwhichhasloadbearingbrickworkwallsofaround10mhigh.

Theoverallstabilityofthebuildingsappearstorelyonthestiffnessoftheboardedroofstructureandthefloorstructurestoactashorizontaldiaphragmstyingtogetherthewalls.

Thegroundfloorappearstobetimberboardedoversteelbeamspossiblyoveranundercroft,butsafeaccessherewasnotpossible.

(viii) LoadingBay:

Thisareawasnotaccessiblebutitlooksasiftheflatroofstructureispossiblyofsteelfillerjoistconstructiononsteelbeamssprungbetweensolidloadbearingbrickworkwalls.

(ix) Office:

Atthewestendofthetankroomthereistwofloorsofofficeswhichappeartosimplybeanextensionofthetankroomstructurewithsomepartitionsandfalseceilingsaddedtocreatethespace.

Theroofcomprisessteeltrussesspanningacrossthewidthofthebuildingfromtheexternalloadbearingbrickworkwalltotheinternalcolumns.

(vii) IceStorageArea:

ThisisineffectasideextensiontotheTankRooms(vi)aboveformingasingleverytallstoreyheightspaceofover10m.

Theroofstructurecomprisestimbertrussessupportingtimberpurlins,rafters,boardsandslates,spanningbetweensteelvalleybeamssupportedoverslendersteelcolumns.

Base of internal columns between Tank Room and Ice Strore Bridge between buildings

Ice Store roof Roof over end of Tank Room by Offices Bridge between buildings

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6.0Obvious Defects in the Existing Structure6.1 Thefourcriticalissuesinassessingtheoverallconditionofan

existingstructureare:

(i) TheQualityofOriginalDesignandConstruction.

(ii) ThePerformanceofitsFoundations/thequalityofthegroundonwhichtheyarebuilt.

(iii) PreviousAlterations.

(iv) Howwellithasbeenmaintained.

6.2 TheQualityofOriginalDesignandConstruction:

Fromwhatwecanseetheoriginaldesignandconstructionwasgenerallyofanaboveaveragequalityforindustrialbuildingsofthisage,thoughtheprocessoficemakingwithlotsofwaterthroughoutthebuildingandtheabrasivenatureoftheicemakingprocesscreatedafairlyaggressiveenvironmentforboththeexposedsteelstructure,andthosesteelelementsbuiltintotheexternalwallsandroof.

Surface corrosion and impact damage to steel beams

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6.3 ThePerformanceofitsFoundations:

TheBGISboreholesindicatethatthewholeofthedockisunderlainbyasignificantdeptofsoftmaterialincludingpeat,withthefirstlayerofreasonablesoilcapableofsupportingheavystructuressuchastheIceFactorybeingtheboulderclayataround10mdepth.ItthereforeseemslikelythatthefoundationstotheIcefactoryareondriventimberpiles.

Therearemanycracksintheloadbearingbrickworkwallsthoughthesegenerallyseemtoberelatedtoproblemsassociatedwiththecorrosionofsteelworkbuiltintothewalls,thermalmovementsoftheuninsulatedroofsandnotobviouslytodowithmovementofthefoundations.

Theoneareawherethecracksinthewallsmayberelatedtodifferentialsettlementofthefoundationsisthenorthwesternendofthe1907/1910buildingwherethereisacrackalmostfullheightofthewalls,andappearstobewideratthetopthanatthebottom.ThisisinthecorneroftheIceStore.

Generallytheexistingfoundationsappeartohaveperformedreasonablywelltodate.

6.4 PreviousAlterations:

AswithanyindustrialbuildinghousingaprocessovermanyyearstherepeatedupdatingoftheprocessgenerallyinvolvessomealterationtothestructureandthisisthecasehereintheIceFactory.Overall,however,thesealterationsdonotappeartohavesignificantlyaffectedtheexistingstructure.

6.5 MaintenanceoftheStructure:

Fromthestateofthebuildingsitisclearthattheyhavenotreceivedanymaintenanceformanyyearsprobablyfromwaybefore1990whenthebuildingswerelastinuse.Largeareasoftheroofcoveringshavebeenremoved,orhavecollapsedandarenowinsuchapoorstate,thatrainwateriscascadingtoptobottomthroughthebuildings.

This,togetherwiththeaggressiveenvironmentgeneratedbythewaterbaseduseofthebuilding,hasledtosomeextensiveandsignificantdegradationofthestructure.

Themostobviousfactorinthedegradationoftheinternalstructureovertimeisnaturallytheprolongedexposureofthetimberandsteelstructuretowaterasaresultoftheicemakingproduction,leadingtocorrosionofthesteelworkandwetrotinthetimberstructure.Severalsteelbeamshavealsosufferedfromrepeatedcollisionswithotherheavymetalitems.Thiswas

Cracked brickwork in Ice Store Cracked brickwork in Compressor Room

Cracks in parapet walls Roof to 1900/1901 Tank Room

Physical and corrosion damage to steelwork

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visibleinbeamsoverlargeopeningsintheexternalwalls,andalsointernallywherethemovementoflargesteelitems(egcansfortheicemaking)clearlyresultedinalotofphysicalclasheswithsomeofthestructure.

6.6 ExternalWalls:

6.6.1 Drawingsnumbers1568/01/15and16showelevationsoftheexternalbrickworkwallsmarkedupwithourobservationsontheobviousstructuraldefectsegapproximatelocationofcracksandtheirlikelycause.

Basedonwhatwecouldsee,thecracksinthebrickworkweregenerallyasaresultofcorrosionofsteelworkbuilt

Impact damage to brickwork around opening in wall

Spalled concrete as a result of corroded reinforcement

Crack in parapet to roof over Ice Store

Cracked concrete where reinforcement is corroding

Roof beam and filler joist roof by 1900/1901 Ice Store

RC frame around windows in 1950s extension

intotheexternalwalls,togetherwithsomethermalexpansionoftheuninsulatedflatroofsandlocallysomeimpactdamage.

6.6.2 RefertotheArchitect’sdrawingsfornon-structuralissuessuchasminorcracks,weatheringetc.

6.6.3 Thereinforcedconcretewindowframeinthe1950sofficeandcondenserroomsisinapoorconditionwithspallingoftheconcreteinseveralareasasaresultofprolongedrainwaterpenetrationoftheconcretecausingthereinforcementtocorrode,expandandpushofftheconcrete.

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6.7.5 Alloftheotherflatroofsappeartobeoffillerjoistconstructionandinseveralareastheconcretecovertothebottomofthesteeljoistshasspalledexposingcorrodedsteelwork.Thisisevidentinthecompressorroom,icestoreandcondenserroomroofsintheoriginalbuilding.Wesuspectthisisalsothecaseintheroofstotheloadingbayinthe1907/1910extension.

6.7.3 Thetimberstructuretotheshallowpitchedroofovertheofficeinthe1950sextensionislikelytobeinaverypoorconditionandsomeofthesupportingsteelbeamsalsoappeartobesignificantlycorroded.

6.7.4 Wenotedsomespallingofconcretelocallyinsomeareasoftheundersideofthereinforcedconcreterooftothecompressorroominthe1950sextensionsuggestingrainwaterhasbeenpenetratingtherooffinishesandtheslabformanyyears.Itislikelythattherewillbeotherareaswherethereinforcementiscorrodedespeciallyinthetopoftheslab.

6.7 RoofStructures:

6.7.1 Generallythetimberboardingandpurlinstothepitchedroofstotheoriginaltankroomsandboilerhouseappeartobeinapoorstateasaresultofprolongedrainwaterpenetration.Thesteeltrusses,however,seemtobeinareasonableconditionthoughitwouldbeprudenttoexpecttofindsomelocalproblemstodowithcorrosionespeciallyalongthevalleyguttertotheoriginalbuilding.

6.7.2 Thetimbertrussestotheicestoreinthe1907/1910buildingarelikelytohavebeenmuchmoreaffectedbyrainwaterpenetrationthanthesteeltrussesandsowewouldexpecttofindsomeextensivewetandperhapsdryrotespeciallyintheendsofthetrussesalongthevalleyguttersandaroundtheedgeofthebuildingundertheparapetgutter.

Roof to 1950s Office

Severely corroded steel joist in flat roof

Roof over Ice Store

Original Compressor Room

Roof to original Tank Rooms

1950s Compressor Room

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6.8 InternalStructure:

6.8.1 CompressorRooms(i)

Rainwaterpenetrationovermanyyearshasledtosomesignificantcorrosionofthesteelbeamstothefirstfloorintheoffice.Thesteeljoiststothefillerjoistfloorarealsolikelytobeaffected.

Elsewhereinthecompressorroomstheinternalsteelstructuregenerallyappearstosufferfromsomesurfacecorrosiononly,whichisnotofmajorstructuralsignificance.

Theconcretegroundfloorinallofthisareacontainsnumerousservicestrenches,plinthsandrecesses.Sometrencheshavesteelcovers,andsomearepartiallyfilledwithwater.

6.8.2 TankRooms1900/1901(ii):

Thesteelstructureabovefirstfloorlevelgenerallyappearstobeinapoorconditionasaresultoftheprolongedrainwaterpenetrationthroughthebuilding.Atthislevelthemostobviousdefectissurfacecorrosionofthesteelworkandthisvariesconsiderablywithonlylocalareasthatappeartobesignificant.

Whilstverylimitedaccesswaspossibleacrossthisareaofthebuilding,itappearsthatatfirstfloorlevel(ietheuppericemakinglevel),theeffectoftherainwaterandtheaggressiveenvironmentduringtheicemakingprocesshasleftthetimberboardedfloorinaverypoorstateandboththeextentandseverityofcorrosionofthesteelframedstructureismuchmoreseriousthanabove.

Attheuppergroundfloorlevel(iethelowericemakinglevel)theconditionofthestructureappearstobeevenmoredeterioratedthanatfirstfloorlevel.

Noaccesswaspossibletotheundercroft,asitwasmostlyfilledwithwater,butfromwhatcouldbeseenfromtheentrance,thesteelworkatthislevelisinanextremelypoorstate.Onlyafewbeamsandcolumnswerevisibleandthesewereseverelycorrodedanddelaminatingtosuchanextentthatinplacestheflangeandpartsofthewebofthebeamsandcolumnsweremissing.

Itislikelythatthefloortotheundercroftisalsoinaverypoorstate.

First floor to 1950s Office Services trench in Compressor Room ground floor

First floor Tank Room

Severely corroded steel column in Tank Room undercroft

Severely delaminating steel beam in Tank Room undercroft

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Thesteelcolumnssupportingtheroofandfirstfloorhaveheavilygussetedbaseswheretheyarefixedtothetopofthegroundslab,whichisthickenedateachcolumnpositionandmustalsobethefoundationtothecolumn.Thesteelworkcolumniscoveredinsurfacecorrosion,butattheirbasethecolumnandgussetplatesareseverelycorrodedanddelaminatinginplaces.

6.8.6 Store(vii):

Thetimbergroundfloorinthisareaisinanextremelypoorconditionwithextensiverottenandcollapsedareasofthefloorstructure.

6.8.7 LoadingBay(viii):

Noaccesspossibletothisarea.

6.8.8 Office(ix):

Localareasofthetimberboardedfirstfloorandthesteelbeamsupportshavesufferedasaresultoftheirprolongedwetstateandinplacesthetimberisclosetocollapse.Thereisextensivesurfacecorrosioninthesteelbeams.

6.8.9 Noaccesswaspossibletolookatthesteelframesupportingthelargewatertankoverthecondenserroom.Itseemsverylikelythatthissteelworkisinapoorconditionespeciallywhereitisbuiltintothebrickworkwalls.

6.8.5 TankRoom(1907/1910)(vi):

Thetimberandsteelframedstructuresupportingthefirstfloorhassufferedfromrainwaterpenetrationandtheaggressiveconditionswithintheicemakingenvironmentinasimilarthoughseeminglynotasseverelyasintheoriginaltankrooms6.8.2above.

Thesteelgrillageatgroundfloorlevelissufferingfromextensivesurfacecorrosioninplaces,inparticularatthesupportsoffthereinforcedconcretegroundfloor.Itislikelythesewillbeareasofseverecorrosionanddelaminationofthesteelwork.

ThegroundfloorcontainsthreetrencheswhichwereabouthalffullofwaterduringourvisitinJanuary.Wesuspectthereinforcedconcreteisnotinagoodcondition.

6.8.3 IceStore(iii):

Thesteelstructurehereappearedtobesufferingmuchlessfromrainwaterpenetrationthanin6.8.2above,thoughitislikelythattherewillbesomebeamswhichareseverelycorroded.

6.8.4 OldBoilerHouseandCondenserRoom(iv)and(v):

Thegroundfloorslabsintheseareasappeartobeofreinforcedconcreteandcontainssomeplantbases/plinthsandtrencheswithabasementunderthewestern-mostarea.Theextentofthisbasementisnotknownasitwasnotaccessiblethoughitseemslikelytobeonlyunderthissmallwestern-mostspace.

Corrosion to bottom of Columns in 1907/1910 Tank Room

U/s first floor to Tank Room 1907/1910

Gurretted bases to Columns in 1907/1910 Tank Room

First floor to Ice Store 1900/1901

Ground floor to Tank Room 1907/1910

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7.0Proposals for Remedial Works to the Existing Structure7.1 Ourexperienceofbuildingsofthisageshowsthatinorderfor

themtocopewithchangesovertime,andtocontinuetobeuseable,thentypicallytheyneedanoverhaulevery25yearsorso,withmajoroverhaulsevery50yearsorso.Itisalsoveryimportantthataspartoftheseoverhauls,allthedefectsinthestructurenotcoveredbythenormalmaintenanceofabuildingaredealtwith.Goodbuildingsofthisagecangenerallybekeptgoingalmostindefinitelyifproperlymaintained.

HereattheIceFactoryitseemsthatitshistoricaldevelopmentfollowedalongthistypicalpathforawhile,ie:

• Built1990/1901and1907/1910

• Firstmajoroverhaul1930s

• Secondoverhaul1950s

butthenwiththefishingindustryindeclineitlooksasifthenexttwooverhaulsaround1975andcertainlyin2000didnothappen.

Forthegeneralconditionofthestructureitlooksasiffew,ifany,ofthedefectsinthestructurehavebeenaddressedinthissecondhalfofitslife.

TheaggressiveconditionsgeneratedintheIceFactorymeantthatthebuildingwouldhaveneededmuchmoremaintenancethanotherbuildingsofitsage.

Itisclearthatthebuildinghasnothadanymaintenancecarriedoutformanyyearsandisnowdeterioratingatarapidlyacceleratingrate.

Lifecycle between major services/overhauls for typical traditionally built building

Lifecycle between major services/overhauls for the Ice Factory

Rate of Deterioration

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Thelongerspanpitchedroofsovertheoldboilerhouse,andthetankrooms(1900/1901and1907/1910)generallyappeartobeinalittlebetterconditionthantheothers.Intheseareasthetimberboardinglookstobeinapoorstateinplaces,butelsewhereitmaybepossibletore-usetheboards.Similarly,someofthetimberpurlinslookasiftheywillneedreplacingandotherslookasiftheycanberetained.

Wesuggestthat:

2. Alltheroofcoveringsareremoved(seealsoArchitects’report).

3. Alltimberboardingisremovedandseparatedintothatwhichcanbere-used(say30%)andthatwhichcannot.Theboardschosenforre-usewillneedtobedry,and/ordriedinacontrolledenvironment.

4. Thetimberpurlinsareremoved,andseparatedtothosethatcanbere-used(say50%)andthosewhichcannot.

5. Thesteeltrussescanthenbethoroughlywirebrushedtoremoveallsurfacecorrosionandrepainted.

6. Thenewandretainedpurlinsandboardscanthenbefixedinposition.

7.2.2 RoofStructure:

Whilstsomedetailedinvestigationwillbeappropriateinduecourse,itseemsatthisstagethattheflatroofedareashaveallsufferedfromextensiverainwaterpenetrationoversuchalongperiodoftimethatitseemsverylikelythattheywillallneedtobereplaced,ontopoftheexistingsteelbeams.Thisappliestoallthesteelfillerjoistroofsandthe1950sreinforcedconcreteroofoverthenewcompressorroom.

Wesuggestthewayforwardhereisforthereplacementworkstocommencewithastagedremovaloftherooffinishesandthentheconcretetoexposethesteelfillerjoistsandreinforcement.Theconditionofthejoistsandreinforcementcanbeassessedastheyareexposedandiffoundtobeinabetterconditiontothatcurrentlyexpectedthenitmaybepossibletoretainsomeofthesteeljoistsandmaybepatchrepairther.c.slab.Atthisstage,however,itwouldbeprudenttoallowforitalltobereplaced.

Theconditionofthepitchedroofstructuresvariesconsiderably.Thesmallpitchedroofovertheoriginal1900/1901office,andthemultipitchedroofoverthestoreinthe1907/1910buildingappeartobeintheworstcondition.Atthisstagewesuggestanallowanceismadeforreplacingtheroofstructureovertheofficecompletely.Overthestoreitlookslikelythatthesteelvalleybeamswillneedsomeremedialworkespeciallywheretheyarebuiltintothewallsandthetimbertrussesarelikelytoneedrepairs/loadrebuildingattheirendswheretheyaresupportedoffthevalleybeams.Allboardingandpurlinsarelikelytoneedreplacement.

7.2 Thefollowingsectionoutlinestheapproximatescopeofremedialworksrequiredtotheexistingstructuretoaddresstheobviousproblemsdescribedearlier.

7.2.1 ExternalWalls:

Allthecracksinthebrickworkneedtobemadegoodbycarefullycuttingoutthecrackedbricksandstitchinginnewbrickwork.Wherethecracksextendfullwidththroughthebrickwork,thisneedstobedonefrombothsides(insideandoutside).

Wherethecracksaretheresultofcorrodedsteelworkthecauseofthecracking,ietheexpansionofthesteelworkasitcorrodesanddelaminates,alsoneedstobeaddressed.Thisinvolvescarefullyremovingthebrickworkaroundtheembeddedsteelwork(egbeamend),introducingtemporarysupportstothesteelworkwhereneeded,sothatthesteelworkcanbethoroughlywirebrushedtoremovealllooserust,cleaned,andthenpaintedwithtwocoatsofbituminouspaint,priortomakinggoodthebrickworkaroundthesteelasabove.Insomelocationsthesteelworkmaybefoundtoalsoneedsomerepairandsoacontingencyshouldbeallowedtocoverthistoo.

Wheresteelbeamsarebuiltintotheexternalwalloveropeningssuchastotheloadingbay(viii),allowforthefirstthreecoursesofbrickworkoverthebeamtobecarefullycutouttoallowthebeamtobetreatedandthenreplaced.

Refertodrawingnumbers1568/01/07to08whichillustratesthelikelyapproximateextentofbrickworkrepairsatthisstagerelatedtostructuralremedialworks.RefertotheArchitects’drawingsforallotherworkstotheexternalwalls.

Roof over Ice Store 1900/1901Cracks in brickwork where steel beam is severely corroded

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7.2.3 InternalStructure:

Withtheenvelopeofthebuildingsmadegoodtheinternalstructurewillneedtimetodryouttodeterminetheextentofremedialworks,thoughtoachievethisstateandtotacklesomeoftheobviousdefectswesuggestthefollowingapproach:

(ii) Clearoutallthedebrisetc.

(iii) Removeallrotten/damagedtimberboarding.

(iv) Pumpoutallthewaterfromthetrenchesandundercrofts.

(v) Wheresteelcolumnshavebecomesignificantlyaffectedbycorrosion/delaminationtheseshouldeitherbereplaced,orperhapsencasedinreinforcedconcretetomaintaintheirstructuralfunction.Thisappliestosomeifnotallofthecolumnsintheundercroftbeneaththeoriginal1990/1901tankrooms.

(vi) Thebuildingsthenneedtobewellventilatedtoallowthemtodryout.Thisneedstobedoneinacontrolledandmaintainedwaysothatitisnotonlyeffectivebutalsoavoidsfurtherproblemsbeinggeneratedsuchasdryrotmanifestingitselfinthetimberstructure.

7.3 ContractorsSiteSetUp

AspartoftheseworkstherewillbeasubstantialcostinvolvedintheContactorestablishinghissetuponsiteincludingallthetemporaryworksnecessaryforsafeaccessinordertoclearoutallthedebrisandcarryouttheremedialworks.Thiswillincludeaccessdecksandstairsaswellasprotectivedecksforsafeaccess.

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Dependingontheproposednewusesitmaybepossibletoreplace(eitherallorinpart)theexistingveryheavydutyfloorstructuresinthetankroomswithseveralnewlighterweightfloorstructures.

Intheareaswheretherearenointernalupperfloors,e.g.originalcondenserroom,boilerhouseandthe1907/1910store,itislikelythattheexistingstructure(wallsandcolumns)couldbeusedtosupportoneormaybetwonewfloors.

RefertotypicalsectionC.

8.0Proposed Alterations to the Structure8.1 Atthisstagetherearenospecificalterationsproposedand

NELChaverequestedsomegeneralcommentsonthefeasibilityofcarryingoutalterationsandaddinginnewfloorswithintheexistingbuilding,allbasedontheunderstandingwehaveoftheexistingstructure,describedabove.

Thefollowinggeneralcommentsassumethatallthedefectsintheexistingstructureareaddressedpriortocarryingoutanyalterations.

8.2 Roof:

Theflatroofedareascanprobablybeusedtosupportsomenewlightweightplant.Shouldtheexistingwatertankovertheoriginalcompressorroomberemovedthenthatareaoftheroofshouldbeabletocopewiththeadditionofnewplant/accommodationofasimilarmasstothewatertank.

8.3 Walls:

Thebrickworkwallsaregenerallyrobustandhavebeenusedtosupportveryheavyimposedloadsaspartoftheicemakingprocess.Itseemslikelywiththeicemakingprocessremoved,thattheycouldbeusedtosupportsomesignificantnewimposedloadsfromadditionalfloors.

Itlooksfeasibletobeabletoremovethetravellingcranebeamsandtheirfixingbracketswithoutsignificantlyaffectingtheintegrityofthebrickworkpiers/walls.

8.4 Floors:

Currentlyitseemslikelythatthefloorsinthemaintankroomsdocontributetotheoverallstabilityofthebuildingandthebrickpiers.

Wherethemainfloorbeamsareconnectedtotheexistingbrickworkwithexternalfixingplatesitmakessensetoretainthesefloorstructuresaspartofanynewscheme,thoughinprincipleitwouldbepossibletoremovethemandreplacethemwithnewfloorstructures.

Timbertrusses

Travellingcrane

Travellingcrane

1stfloor

SteelgrillageontopofRCtrenches

Steelbeam

Steelcolumn

IceStore TankRoom

Section C

Potentialnewfloorsbuiltoffexistingstructure

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9.4 Itneedstoberecognisedthatthescopeofremedialworksin(iii)aboveisaimedataddressingtheobviousdefectsinthestructure,itisthenatureofbuildingsthatsomedefectsarehiddenandmayonlybecomeobviouseitherduringtheworksonsite,orindeedlaterinthelifeofthebuilding.

Allremedialworksshouldbedesignedtosympatheticallyrepairorimprovetheexistingstructure,thoughagainitshouldberecognisedthattheseworkscannotbecomparedtonewconstruction,andareaimedatextendingtheusefullifeofthebuildingwhichisindeterminate,andreliesonhowwellitiscaredforinthefuture.Itwouldbeusefultodevelopasimplemonitoringregimeaspartofthedetailedproposalstoassistwiththeassessmentofthesuccessoftheproposalsandasacheckonfuturemovementsofthestructure.

9.5 Aspartofthenextstageoftheworkswerecommendaconservationassessmentismadeofthebuildingsandtheircontentstoassistinthepreparationoftheproposals.

9.3 AsdiscussedwithNELCthisreporthasconsideredthelikelyscopeofremedialworksrequiredtoaddressalltheissuesraisedintheNELCScopeofWork.

AnestimatedcostoftheseworkshavebeenpreparedbyKMCS.

Twofurthercostestimateshavebeenprepared:

i. forworksofalesserscalethanabovejusttoaddressrainwaterpenetrationofthebuilding.

ii. Simplytoenclosethebuildinginasheetedscaffoldtotryandkeeptherainwaterout.

Inverygeneraltermsthelikelyeffectofthethreealternativescostedare:

i. Scaffoldonly:Thiswillslowdowntherateofescalationofthedegradationofthestructure,butshouldbeconsideredasatemporarymeasureonlybeforeproceedingwithmoresubstantialworks.

ii. LesserScaleofWorks:Thiswilladdressthemostobviousdefectsinthestructureandprovideabreathingspacebeforecarryingouttherestoftheworksin(iii)below.

iii. NELCFullScopeofWorks:Thisshouldpreparethebuildinggenerallyforconversionorrefurbishmentonceausehasbeenfound.

9.0Next Stage9.1 Thisreportisaimedatprovidingaveryoutlinescopeofworks

anda‘ballpark’costestimateofthelikelyremedialworksneededtotheexistingbuilding.

9.2 Inordertopreparemoredetailedproposalsforthepurposesofobtainingtendersfortheworkthenwesuggestanenablingcontractisbuiltintotheprogramme.Thisenablingcontractwouldincludesomephysicalopeningupworkstoassistindeterminingtheseverityofdegradationofthestructureandbetterdefinetheextentofremedialworks.Itcouldalsobeusedtocarryouttrialrepairsforagreementwithinterestedparties(e.g.EnglishHeritage)priortocommencingthemainworks.

Theseinvestigationworkswouldinclude:-

• Breakingoutareasoftheflatroofedstructuretorevealtheseverityofcorrosionoftheembeddedsteeljoistsand/orreinforcement.

• RemovalofareasoftherottentimberfloorsintheTankRoomsandIceStorestohelpclarifytheseverityofcorrosionofthesteelstructure.

• Trialpitstoexposethefoundationsandcheckwhetherthebuildingissupportedofftimberpiles,andwhetherthepilesextendabovethecurrentgroundwaterlevel.

• Providingsafeaccesstopreviouslyinaccessibleareasofthebuildings.

• PumpingoutofwaterfromtheundercroftandServiceTrenches.

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10.0Existing Fabric, by Richard Griffiths Architects (RGA)

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Appendices

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Appendix AInformation Received

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Appendix BDrawings by ABA

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Appendix CDrawings by RGA

PreparedbyDavidJohncox,withsectionsfromRichardGriffithsArchitectsbyJohnWoodcock,andfromKCMSbyColinHayward.ReviewedbyMichaelCoombsIssuedFebruary2010

T:\1568\1568-001\DTPData\IndesignDocs\1568-01-GrimsbyIceFactoryAppraisalofExistingStructure.indd

ThisreportisthecopyrightofAlanBaxter&AssociatesLLPandisforthesoleuseoftheperson/organisationtowhomitisaddressed.ItmaynotbeusedorreferredtoinwholeorinpartbyanyoneelsewithouttheexpressagreementofAlanBaxter&AssociatesLLP.AlanBaxter&AssociatesLLPdonotacceptliabilityforanylossordamagearisingfromanyunauthoriseduseofthisreport.

AlanBaxter&AssociatesLLPisaLimitedLiabilityPartnershipregisteredinEngland,numberOC328839.Registeredoffice75CowcrossStreet,London,EC1M6EL.©AlanBaxter&AssociatesLLP2009

Alan Baxter

75 Cowcross Street London EC1M 6ELtel 020 7250 1555fax 020 7250 3022email [email protected]

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