B.W. report 3

JEFFREY TITMUS : RESTORATION WORKS :

www.hertsrestoration.co.uk

Historic building consultancy

RE: BEAUMONT WORKS. AL1 5HT: E.H.I.D 163464

CONDITIONS OVERVIEW/PROCESS REVIEW 2014

Sept 2011, instructed by owners Michelle Murray/Steelcraft Construction to carry out a

conditions survey report of the buildings comprising Beaumont Works, a combination of late

Victorian industrial factory structures built between 1900 -1903. The site was listed in the 1970’s

as part of the national re-listing program. The main listing features being the ornate detailing of

brick and terracotta façade and entrance ways to coped Dutch gables fronting Sutton Road St.

Albans. Construction is typical of industrial era solid brick masonry supporting ‘Northern

Light/Saw Tooth’ roof covering of Welsh slate and wired glass panels supported by a

combination of mild steel, cast and wrought iron trusses.

The original 5 bay footprint fronting was extended and added to with additional 2 storey bays to

the left and right flank elevations (N+S) around 1911, continuing in the same vernacular. A dual

pitch building was later added to the rear of the right flank 2 storey bay. Evidence (OS map1924

+ 37) of later additions to the rear have since been demolished.

The structures were constructed for Mr. J. Nicholson, a water proof clothing manufacturer who

had relocated from Lancashire and his ‘N’ & ‘C’ initials/logo are displayed on each of the ornate

gable facades’.

Survey Overview/2011:

The main structures are common of late Victorian industrial/factory constructional design

techniques; solid masonry supporting ‘northern light/saw tooth’ roofs utilizing the natural light

source. Combination of the then preferred mild steel, cast and wrought iron truss designed to

prevent internal thrust stress/spread to the supporting walls required in large work production

space. Common materials used comprised of locally sourced soft dark red facing brick, wired

glass panels (northern light), Welsh slate, with integral formed cast iron valley box gutters. The

main aesthetic/design focus being the fronting to Sutton Road; coped Dutch gables, bay entrance

way door-cases of Terra-cotta tile dressing, faience, break-front cornice with glazed tiles.

Gauged arches with key stones over timber mullion casements.

Built for the manufacture of waterproof clothing (Nicholson & Co.), expansion of production in

the early 1900’s allowed the additional 2 storey bays to north and south aspects, Coach Mews

and Hedley Road, following the original design for ‘northern light’ source.

C18+19> industrial structures were generally over engineered being function specific. Innovative

in design and evolving technical knowledge, these structures were built to last. Adaptation,

conversion and usage has enabled them a significant place in our urban landscapes. However,

maintenance of these working structures provides unique logistical issues with regard to safe

access within today’s health and safety regulations. Inherently and specifically in material and

design; the layout of the ‘saw-tooth’ roof configuration and linked combination of glass, cast

iron and slate within the 'saw-tooth' roof design. All materials have a lifespan. Individually units

can be repaired and or replaced. However within the ‘saw-tooth’ configuration, safe access for

maintenance operations are challenges today not envisaged when originally designed.

The Beaumont Works structures have missed the major overhaul periods usual for the lifecycle

of an industrial building. Extensive replacement and improvements are now a priority.

Beaumont Works was purchased in 1970 by the present owners and was part of the re-listing

program the following year. Maintenance of the structures up to that date comprised mainly of

individual localized repairs of the slate/glass roof coverings, and part replacement to the Hedley

Road pitched elevation irrespective of the potential additional weight loading and aesthetics. The

profiled formed cast iron valley box gutters have been repair coated in asphalt and bitumen. The

corroded and leaking glazing bars and rotted fibre seals to the glass panels have been covered

with plastic adhesive flashings. The large 2 storey bay slate roof pitch to the north is entirely

covered in multi-layered bitumen paints, with extensive nail fatigue to the remaining slated

slopes. ‘Short-term’ attempts at weathering have inevitably and consistently failed and the

substructure of structural softwood timbers and soffits, wrought and cast iron truss members now

suffering irreparable damage.

The present owners have instructed us to provide a conditions report with subsequent

recommendations.

The summary appraisal of which comprised the replacement of the roof coverings and associated

fabric within listed building regulations for which listed building consent was obtained. With

specific consideration to the unique constructional and design layout of these structures,

specialist design engineers for the access/temporary works and specialist contractors for the

supply and installation of the traditional materials required were sourced and subsequently

recommended to tender stage.

Process/Proposed Roof-Reinstatement Options: (Ref: App/Documents/Photo Identification)

Surveys were commissioned to ascertain the feasibility of such an undertaking, considering that

the works units were to remain fully occupied as leased to individual, on-going and thriving

businesses. Material and method specifications were proposed to satisfy listed building consent

planning requirements.

Access Scaffolding of historic structures must be totally independent with neither ties nor

loading to the existing fabric. Temporary roof support or interventions through to within the

working units were totally unacceptable

In discussions with engaged specialist access company Layer (GDR) it became clear that the

undertaking would need to be 3 phased due to the structures span size and configuration.

Specialist access design engineers (48.3) proposed and calculated Phase 1 (drwg STS P1-6), a

system to entertain Unit 1*Body-limits Gym, the 2 storey bay North (Coach Mews), spanning

south to the third valley box gutter at Unit 2* Caxton Blinds. Approximately 40m x 40m a

maximum temporary roof capacity. From this temporary roof covering internal suspended work

platforms where designed to service the internal pitched slate elevations and glazing works.

Additional kentledge loading/bearing requirement was calculated to support the original working

design. A unique feature of the Layer (GDR) system is the on-ground bay-erection and crane lift

to gable end bay linking of the sections that make up the roll-out roof covering system on full

length eaves casters N + S.

The northern eave scaffold being exclusive to firm ground (Coach Mews), with the southern and

west eave scaffold needing to bridge span the structure 30m from Sutton Road through to the

rear car park. The ‘bridging’ eave scaffold S (W>E) required support on designed full length

steel members (drwg STC 20-25) again with additional kentledge and ground bearing capacity at

either base. Mobile crane lifts of the rear car park assembly of full-length steel member bridging

sections and the southern rolling roof eaves caster construction into position S. Scaffold base

axial point leg loads and mobile crane travel loads were calculated to quantify ground bearing

capacity.(STC C 1259addA)

Scaffolding calculation, steel works design and crane load calculations were reviewed and

confirmed.(revSTC Calc C.1259A(v2.1) drwg STC 1259 1-6revA)drwg STC 1259 20-25A)

A second below ground survey was carried out following discovery during decommission of a

collapsed underground storage (heating oil) tank cover of other redundant services, voids and

poor surface conditions to the rear car park abutting and part beneath the structure Unit 1.

Leaking utilities/drainage systems, ground/surface water catch pits, poor compaction and

honeycomb voids to concrete/tarmac, with a history of repetitive pot-hole repairs were located

directly within the main rear works area. Solution-finding, trial-pit/core drill calculations and

reports are with consulting engineers Gyoury Self who are to devise and provide material

specification for instating temporary works foundations to construction purposes prior to any

proposed roof refurbishment schedules.

Internally and throughout the occupied/working units (Body-limits Gym 1*+ 2*part Caxton

Blinds), Phase One required internal safety scaffold crash decks and sealed working

platforms/ceilings, to be positioned spanning full width at wall/roof plate/ceiling height, with

temporary lighting and heating to be required for the duration of the works.

It became clear following the temporary works tender quotations that the ‘logistical costs’ alone

of Phase 1, with the units fully occupied, and subsequently Phases 2 and 3, rendered the funding

of the proposal unfeasible. Phase 2 (encompassing the remaining span Unit 2 third valley gutter

through to Hedley Road ( S.), a mirror image of the Phase 1 design, with a separate design for

the required unit works of Phase 3.

Costs of implementing the traditional fabric/material replacement were a mere percentage of the

safe access and logistics of the temporary works proposals.

Emergency repairs and attempts at localised weatherproofing of the structures with the latest

‘hi-tech’ materials are on-going but are temporary, costly and symptomatic without any real

confidence of long-term success (and have indeed consistently failed).

Attempts at weatherproofing Units

The Internal degradation of the substructures (Baltic) softwood timbers (rafters and soffits), iron

trusses have now become vulnerable. The ‘northern light’ glazing panes regularly slip due to the

rotting of the original fibre seals and fixings with further water ingress. Similarly with the coated

slate elevations, the t&g timber boarded soffit and softwood timber rafters are now remaining

permanently wet and decay due to trapped rainwaters.

Regarding the internal working environments; Heat loss and wasteful energy consumption,

remains unsustainable within the present deteriorating conditions. A proposal to coincide with

total refurbishment could include new ground-source energy, water recycling, efficient lighting

division, thermal efficient glazing and wall and roof insulations all within the structures historic

context. It has been suggested that a change of use proposal represents a unique opportunity to

sensitively convert this former industrial building to a use that will secure funding its future.

Summary of surveys carried out @ Beaumont Works; 2012/13/14:

The solid masonry structural walls of mainly English bond, part Flemish bond facing brick are in

good condition, with no major deflections, degradation or historic decay. Similarly, the internal

solid concrete floors that run throughout with substantial suspended timber floor members to the

2 storey units. Fenestration, part original timber mullion and part replacement are also in good

condition and functional. No opening up or investigation of foundations was carried out nor

deemed necessary. High level inspections were carried out via, ladder and mobile hoist.

All problems of degradation stem from water ingress via most roof slope coverings, slate and

glass, the integral shared valley box gutters, rainwater disposal systems and rear location

underground systems and services.

Although presently structurally sound, the water ingress and disposal systems are an immediate

priority in the preservation of these historic structures.

1/Elevation/Roof slope; ‘northern light’ 120xNo.Wired glass panels in lapped rows. Eaves to

ridge. Upper glazed slope discharge via pvc rainwater gutter & downpipes to lower glazed slope,

and discharge to rectangular cast iron formed section and downpipe to underground. Vertical

brickwork has water and salt staining as a result. Stepped lead flashing to Dutch gable abutment.

Slate verge condition to rear gable. Water ingress via corroded glazing bar seals and flashings.

Elevation 2/Roof slope; Originally Welsh grey/black slate covered in multi-layered bituminous

paints/coatings.

Original angular clay tiles slate ridge also coated. Bitumen painted stepped lead flashing to

Dutch gable end abutment. Decayed softwood timber fillet to end rafter verge condition to rear

gable. Half round pvc rainwater guttering and downpipe discharge to horizontal zinc formed

valley box gutter (1) abutment with Unit 2>.

Cast iron formed ‘ogee’ gutter and downpipe to front elevation Sutton Road and pvc hopper

outlet to rear to underground. Water ingress and trapped rainwaters sealed within roof layers.

Elevation 3/Roof slope; ‘northern light’ 120xNo. Wired glass panels in lapped rows,3xNo. raised

to vent panels.

Slate top eaves and angular clay ridge with ventilation stack/pipe. Stepped lead flashing to Dutch

gable end. Slate verge condition to rear gable. Rainwater discharge directly to abutment/shared

valley box gutter with Unit 1 with downpipe to underground. Water ingress due to fatigued

valley box gutter membranes and glass panel seals.

Elevation 4/Roof slope; Forward section, original footprint, Welsh grey/black slate, rear section

of concrete interlocking tiles to rear gable. Angular clay ridge tiles. Slate section discharges

directly to shared valley box gutter (2) Bitumen coated stepped lead flashing to Dutch gable end

abutment. Concrete tile section discharges via pvc half round gutter and downpipe to

underground. Water ingress via slate-tingle nail fatigue repairs and ridge vent coated inserts.

Elevations 6/8/10 Slate roof slopes, 5/7/9/11 Single Wired glass slopes comprise original

footprint configuration.

Elevations 11+12 have been extended during the site expansion and addition of the 2 storey

structures N + S and prior to the dual pitch building elevations 15-18 at the rear.

Elevations 12 + 14 roof slopes have been re-laid in concrete tiles with rotted under-felting

probably 1970.

The formed cast iron Valley box gutters Nos 3>6 have been coated in asphalt and bitumen,

discharge via the formed cast iron gutter outlets to the front elevation Sutton road and to rear

hopper and downpipes to underground. Valley gutter 6 rear discharges internally through Unit 5

via sealed pipe to underground. Water ingress via fatigued valley membrane surface fractures.

Elevations 13/16+18 Double row of wired glass panels, with raised venting panels and with

narrow slated verge sections. Consistently and dangerously loose full length glass panel slip due

to corroding seals and metal fixings.

Original 5 bay Dutch gable, 1 through 5 ridge lines have zinc formed flue/vent stack inserts, now

coated, with leaks through to units.

Wired glass panels to slopes 11/13/16+18 have vent panels and slipping full length glass units

with subsequent ingress.

Conclussions:

1/ Water ingress via slate and glass roof coverings; box valley gutters, abutment up-stands and

flashings at verticals, flue/vent stack inserts and poor verge conditions, corroded glass panel

seals and slipping units are all an immediate priority.

2/ Rear and car park ground conditions; surfaces, subsurface voids and underground service

conditions generally are a major hazard to any refurbishment proposals and an immediate

priority. Past development and demolition have created a subsurface to the rear with potential

here for serious collapse under any increase/pressure or implied loads.

Complete new rear ground conditions, including foundations, services and surfaces need

reestablishing prior to any unit refurbishment works schedule.

Acknowledgements: Surveys/Designs:

Paul McConville Roof Associates; Adam Neat Roofglaze Ltd; 4.83 Scaffold Design Engineers

BenBeaumont/Gavin Dempsey; P+N Consultants and Design P. Somani Ceng. MI SructE; Nick

Archer Gyoury Self Consulting Eng AMI StructE; Plowman Craven & KND underground

surveys Ltd.

J. Titmus. 32. Field Road. Oxhey. Hertfordshire. WD19 4DR Tel/Fax 01923 250247

[email protected]

S.P.A.B. I.H.B.C. ICOMOS. VSA. AECB. Historic Building Surveys Planning Specifications Project Management Drawing Service

BEAUMONT WORKS SITE

Site layout looking N /\

Site Layout viewed S /\ Underground services survey overlay (Drwgs KND+ Plowman Craven)

PHASE ONE

Site Layout N /\ Scaffold base overlay (Drwg 48.3 STC1259 1)

Site Layout S /\ Scaffold axial leg load overlay underground services (Drwg KND+48.3)

PROPOSED 3 PHASED WORKS

LAYER (GDR) KEDER XL ROLLING ROOF SCAFFOLD FIRST BAY ERECTION

SAW TOOTH ROOF CONFIGURATION

INTERNAL IRON TRUSS TO UNIT

SAMPLE VALLEY BOX GUTTERS

Units 3+4

WATERPROOF COATING TO SLATE ELEVATIONS

PREVIOUS ATTEMPS AT WATERPROOFING SLATE

TRAPED MOISTURES WITHIN SURFACE LAYERS

INTERNAL SOFTWOOD TIMBER DECAY

REAR CAR PARK UNDERGROUND CONDITIONS

UNDERGROUND STORAGE TANKS

HARDSTANDING/TARMAC SURFACES OVER SERVICES

LOCATION OF REAR CAR PARK SURFACE IMPLIED SCAFFOLD LOADS

AXIAL LEG POINT LOAD LOCATIONS

SOUTHERN EAVES STEEL SPAN STRUCTURE SUPPORT

SPECIALIST CONTRACTORS 2012

TENDER QUOTATIONS OBTAINED 2012 (AVERAGED)

ROOFGLAZE LTD

MC.CONVILLE SLATE ROOFING

TRAD SCFFOLDING LTD

MACLEAN GROUNDWORKS

RAINCLEAR RAINWATER GOODS

PHASE ONE: UNIT 1’BODY LIMTS GYM’ + UNIT 2 ‘CAXTON BLINDS’ (3rd VALLEY BOX GUTTER)

ALL TEMPORARY WORKS SCAFFOLD ACCESS/ LOGISTICS £350,000.

RESINSTATEMENT TRADITIONAL WELSH SLATE (PENRYN) £75,000.

REINSTATEMENT GLAZING £80,000

REAR CAR PARK GROUND WORKS INC TEMPORARY WORKS FOUNDATIONS £145,000.

INTERNAL UNITS TEMPORARY WORKS £ 55,000.

RAINCLEAR CAST IRON RAINWATER GOODS AND GUTTERS £ 35,000.

(2015 COSTINGS TO BE @ PRO-RATA % INCREASE)

WINTER 2013

REF: EXTERNAL DOCUMENT LIST:

KND SITE PLAN AND UNDERGROUND SURVEY

PLOWMAN CRAVEN UNDERGROUND SURVEY

48.3 SCAFFOLD DESIGN CALCS + STC 1259 Rev (1-6)

48.3 SCAFFOLD STEEL WORKS STC 1259 (20-25)

48.3 AXIAL LOAD OVERLAY (AddA)

J. Titmus. 32. Field Road. Oxhey. Hertfordshire. WD19 4DR Tel/Fax 01923 250247 [email protected]

Historic Building Surveys Planning Specifications Project Management Drawing Service

2 STOREY TRUSS CONFIGURATIONS SINGLE STOREY TRUSS CONFIGURATION

TRUSS TO WALL HOUSING TRUSS LINKAGE CAST/WROUGHT IRON

S/W TIMBER BOARDING/RAFTER/PURLIN CAST T-BAR WROUGHT TENSION ROD

MILD STEEL GLAZING BARS

REAR VIEW OF EXTENDED BAYS 1 + 5 c1911 @ TIME OF 2 STOREY BAY ADDITIONS N. + S.

PROPOSED LAYER (GDR) ROLLING TEMPORARY ROOF COVER AND ACCESS SCAFFOLD DESIGN

REAR VIEW OF PHASE ONE PROPOSAL

FRONT VIEW OF PHASE ONE (TWO) PROPOSAL

INGRESS TO BAY 1 FRONT GABLE END MASONRY

MOISTURES TRAPPED WITHIN ROOF COVERINGS UNIT 3

PERSISTANT WATER INGRESS TO SUBSTRUCTURE REAR UNIT 1

FLOW OF TRAPPED RAINWATER INGRESS TO SOFFITS

FRONT ELEVATION SUTON ROAD / PROPOSED PHASED WORKS

FRONT ELEVATION PROPOSED PHASED WORKS>SOUTH

FRONT ELEVATION PROPOSED PHASED WORKS>NORTH

J. Titmus. 32. Field Road. Oxhey. Hertfordshire. WD19 4DR Tel/Fax 01923 250247 [email protected]

S.P.A.B. I.H.B.C. ICOMOS. VSA. AECB.

Historic Building Recording Surveys Specification Schedules Planning Applications Project Management Drawing

Services.