O:\_misc projects\_STRUCTURAL DSA REPORTS\Harborneclock1REV.1.0.doc

Structural Survey

Of

Harborne Clock Tower Centre,

High Street, Harborne,

Birmingham. B17 9NJ

Ref: 72069/SE/BK/V1 10th August 2010

O:\_misc projects\_STRUCTURAL DSA REPORTS\Harborneclock1REV.1.0.doc

CONTENTS

1. Introduction

2. Description

3. Procedure

4. Observations

5. Discussion

6. Recommendations

7. Photographs

1.0 INTRODUCTION

The Structural Section of Urban Design was requested by Iain Pay (Building

Surveyor, Urban Design) on 17th

March 2010, to undertake a survey of the

building known as Harborne Clock Tower Centre on Harborne High Street,

Harborne, Birmingham, due to reports of debris falling from high levels of the

building on to the public highway.

In particular, it is understood that due to some elements of the building being

severely deteriorated, one reasonably large piece of feature stone had become

loose and fell onto the public pavement along High St; Harborne.

2.0 DESCRIPTION

The listed building predominantly comprises traditional brickwork, terracotta

and natural stonework all covered in plain clay tiling onto traditional timber

roof. It is understood the building was built in late 1800's.

3.0 PROCEDURE

An initial visit to site was made on 8th

April 2010 when it quickly became

apparent that a protective scaffold was necessary to safeguard members of the

public from further falling debris and an access scaffold to facilitate the

inspection of all high level elements of the structure. Due to the urgency of the

situation, the protective scaffold was already being erected under the guidance

of Iain Pay of Urban Design.

Further visits were made on 29th

April , 2nd

June 16th

July, 20th

July and 4th

August 2010 to carry out various structural inspections and to identify areas that

required to be opened up including identifying positions of access scaffold.

4.0 OBSERVATIONS

The weather was generally dry on many occasions, slightly raining on one day

and a light to moderate wind on the day of high level inspection of the outside

elevations of the clock tower itself.

External

Roof

Generally, the roofs to the building, including the clock tower, are in a

dilapidated state and numerous past repairs are evident. Roofs to the building in

general are noted to be slightly sagging. However, the clock tower roof is very

steep and sagging to this is not visible.

There are numerous areas of the roof where:

• a leaded crest over the roof facing York Street can be swayed by

reasonable hand force. This will need to be taken down and re-fixed

• relatively heavy terracotta finials to the ridges to some of the gablets are

loose that can be moved by hand whilst applying a reasonable amount of

force

• the ridge tiles are sitting loose in position under their own self weight

and these can be moved by hand

• opened joints amongst slipped and missing verge tiles

• loose mortar or missing under-cloak at verges

• missing and broken roof tiles in the expanse of the roof over various

rooms to the building

• the above ground drainage system including gutters, down pipes and soil

stacks, is in dire state; cracked or broken where leaking or over-spilling

water is causing damp to walls and foliage growth in the walls

• lead flashings to the roof are severely breaking away and may require to

be re-bedding or total replacement

• valleys showing signs of past water penetration and lead work requiring

to be at least re-bedded. The valleys require to be substantially repaired

or reconstructed where the timber at the base of any of the valleys is

likely to be rotting

• Ironwork or steelwork where noted including to areas in the clock tower,

has corroded significantly and in such cases is affecting the brickwork by

the expansion caused by the rusting of as such.

• Timber fascias or soffits are rotting

More specifically, the following observations relating to the clock tower were

made:

• There were four iron finials above the clock level which appeared to be

fixed into the masonry. One of these finials was just held in position by a

pin and was easily removed by the scaffolding or roofing team. Another

was tested by me and was easily removed by a hand turn. The other two

remaining finials are suspect, one of which is held by some pressure

from the scaffolding board wedging it. The finials would seem to weigh

approx. 5 kg. For health and safety reasons, the two loose finials have

been taken down and stored away by the contractor.

• The removed finials could have potentially caused a fatality to members

of the public should these have fallen off due to wind etc. As the

remaining finials are suspect, these should be taken down, refurbished

and re-fixed.

• The steep roof to the tower has had limited patch repairs carried out in

the past. However, some missing plain clay tiles are evident in various

locations. Amongst these, quite a few of the hip tiles are missing and in

numerous other roof areas they are loose and their fixity suspect.

• There are large areas of perished brickwork with delaminating surfaces

and loose mortar joints. The brickwork and terracotta around the clock

is particularly badly affected.

• There are four GRP finials - probably replacing old terracotta. These are

fixed onto the ridge tile to a gablet in each face. One of these finials on

its base can be moved by hand with a reasonable force applied.

• Iron gutters and down pipes (some of the down pipes are of asbestos

construction) are corroded including their fixings into the wall. There is

evidence of missing or broken tiles landing into the gutters and they are

remaining there even today.

Elevations

There are numerous areas of perished to all elevations including a total area of

walling over the entrance to the building from York Street, feature brickwork

surrounding the louvre openings to the clock tower, whereby it will be necessary

to carefully remove and re-build such affected brickwork. Some in-significant

bowing of walls or tall piers is noted.

Much of the perished brickwork is delaminating and, evidently the facing layers

can be easily removed by hand. Some of those layers are noted to be fairly thick

and should they fall from a height, may cause injury to members of the public

below.

Similarly, much of the stonework noted to window and door heads and sills,

louvres to the clock tower, elemental features including at eaves, parapets or

coping stones; string courses etc. is significantly eroded and will need specialist

attention in cutting out and re-bonded with new or careful replacement.

Slight cracking to brick work is evident in the rear elevation including just

below verges to gable ends and over a lintelled opening to the rear.

Cracking or opened up joints and in brick perps is evident to the terracotta

arches to the external elevations.

The elevations that are worst affected by the above noted defects in brickwork

and stone or terracotta appear to be those facing High Street, York Street and

sections of the rear elevations when viewed from the rear courtyard serving the

building.

More specifically, the following observations relating to the Clock Tower were

made:

• an area of brickwork contained a fairly substantial but rusting fixing -

possibly a fixing to a former down pipe

• Brickwork including the terracotta around the clock tower including at

the corners of the tower and around the louvres is badly perished and

missing in places. There is evidence of surface de-lamination to these

bricks. Also, mortar joints are loose in these affected areas of walls.

• stone sills to the openings in the walls to the tower are badly perished

and some of the sections of the sills are missing

Chimneys

There are chimneys serving the main building and those at the rear of the

building near the car park that are either bowing, cracking or that their

brickwork is loose and will need to be either reduced in height or re-built.

One particular chimney stack to the rear is very tall and slender. To this chimney

stack, there is evidence of opened joints including perps, perished and missing

bricks. Iron strapping and rods designed to stabilise the stack are corroded to a

degree requiring remedial attention or replacement. The stack itself will need to

be reduced in height.

Another but smaller chimney stack is dangerously crumbling, whereby bricks

can be moved or even picked up by hand. This has already been temporarily

secured by scaffold and netted around to prevent any fall out.

Drainage

The underground drainage system appears to be of an age such that it requires to

be surveyed and tested by a specialist and may require repairs to be carried out

to the system as may be necessary. This is to avoid any leaking drains affecting

ground conditions and causing building settlement problems.

Internal

All rooms were inspected that contained high ceilings. The roof structure

comprises timber jack rafters supported of timber purlins which are in turn

supported off principle timber trusses. Most of the ceilings are lath and plaster

fixed to the underside of the jack rafters. Evidence of water penetration is noted

and such areas have been be opened up including those areas where it was

essential to determine certain structural elements and their condition including

brick walls, roof structure, ceilings and floors.

Upon viewing the opened up areas, such as the roof valley positions from below,

there do not appear to be any major implications. Some of the fixings in the

joints have slipped and thereby allowing the principle timber members to also

slip in turn.

Some of the walls and timber floors, particularly to the narrow store and the

section of building occupied by the caretaker at first floor located at the end of

the building - are noted to be affected by lateral and rising damp.

Some of the external walls to the part of the building occupied by the caretaker

are showing severe damp conditions and foliage growing on the inside faces -

behind the plastered finishes. It appears that water ingress had been abundant

and some may still be present for the above to occur.

Severe dry rot has been identified in at least one section of the building where

the timber floor and brick walls have been affected. Floor to that area has been

temporarily made safe.

Upon inspection of the internal masonry cross walls, there do not appear to be

any significant structural problems or to the overall stability of the building.

5.0 DISCUSSION

Presently, there generally appears to be no fundamental overall stability issues

with the structure, the exception being the high level chimneys. However, there

are extensive and significant material defects, throughout the building,

predominantly at high level. These defects need to be addressed in the near

future to ensure no consequential damage to the structure occurs.

The main problems with this building are the roof and perished/weathered

masonry and terracotta.

Debris has been reported to have fallen on a number of occasions and from

observations this situation would have continued with potentially fatal

consequences. Such examples would include the approximately 700mm high

metal finials that were removed by hand from the tower roof and the hip and

ridge tiles that were held by their self weight. There are further components to

the building that have been identified to be loose or corroded embedded and

require attention. These defects have vindicated the decision to erect the

protective scaffold.

There is some age related cracking to the building. However, nothing that would

not be expected in view of the age of the building.

Dry rot has been identified in a section of the building. This would require

immediate attention as this type of rot has the potential to spread quite quickly if

not remedied.

6.0 RECOMMENDATIONS:

Roof covering is likely to require major work including replacement in many of

these areas. The integrity and fixing of the tiles and battens needs to be checked

by specialist roofing contractor.

As noted above, cracking, bowing or loose brickwork to chimneys will need to

be addressed by either reducing their height, repairing or rebuilding.

The various finials and crests including those that have been identified to be

either suspect or loose require to be removed and refurbished, and then

satisfactorily re-fixed into position. Any embedded iron work that has corroded

needs to be removed and suitably replaced where necessary.

Timber fascias and soffits will need to be replaced.

Perished brickwork or stonework will need repairing or replacement including

to the clock tower. Any replacing will obviously need to be sympathetic with the

existing building and to match including mortar mix. Large areas of brickwork

will require pointing in particular those at high level. A nominal amount of

brickwork stitching will be required to deal with localised cracking in the

masonry. More immediately, loose or delaminating masonry should be removed

or appropriate netting carried out around the scaffold to prevent any fall out onto

members of the public.

The above ground drainage needs to be replaced.

The underground drainage needs to be surveyed and tested and any identified

defects addressed.

A timber and damp specialist should be consulted to consider the noted areas

observed to be damp or rot affected. Any noted defects should be rectified in

accordance with their recommendations.

Author: Bob Kumar, BSc (Eng); Str. Eng; DSS, Urban Design

0121 303 6574

Reviewed: S L Bates; C.Eng; MICE, Group Eng; DSS, Urban Design

7.0 PHOTOGRAPHS.

Tall chimney Close up of tall chimney showing cracking

Dangerous chimney with loose bricks evident

Clock Tower

Loose ridge, broken, slipped and missing tiles

Moveable crest on ridge

Leaking drainage with foliage growing in walls

Foliage growing

behind internal

finishes to external

wall

Perished and cracked arches over openings

Perished and weathered brickwork and stone copings/string coursing

Uncovered dry rot from timber floor

De-laminating brickwork easily removed by hand (including at high level)