brendan miles building pathology

8/6/2019 Brendan Miles Building Pathology

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Brendan Miles

Building Pathology Assignment

Contents Page

(1) F ront cover(2) Contents Page(3) Introduction(4) George Street Churc h (5) 2 Problems wit h Churc h (6) Clearing out Mortar(7) Replacing Window F rames(8) 33 Main Street Survey(9) Problems wit h Main Street Survey(10) Settlement Problems(11) What is Subsidence(12) Repairing Subsidence(13) Façade Maintenance Plan(16) References



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Introduction

A building defect is defined as a material, component or finish which does not meet

its expected performance criteria. Building Pathology and Defect Diagnosis can

relate to problems in all types of buildings. The results of defects and the analysis of

how the defects should be put right can occasionally be stra ightforward, but often

requires special techniques and assistance, and a good deal of lateral thinking.

Therefore, technical expertise and an understanding of building construction are

essential to correctly identify the cause of building defects and the r emedial

measures required to put the defect(s) right

Instructions typically include inspection, analysis and reporting on the following

�Water penetration (dampness & ingress)

�Condensation

�Defective detailing and finishes

�Movement and cracking

�Concrete and Deleterious Materials

�Curtain Walling, Cladding and Glazing

�Heritage and Conservation

This report aims to identify 2 different defects from two different buildings and go into

detail how the defects have occurred and then propose remedial specification for

each repair. The report will also cover maintenance and repair schedules.

The first building to be surveyed.

George Street Wesleyan Methodist, George Street, Oldham, OL1 1LP

George Street Wesleyan Methodist is located at OS Grid Reference - SD 924049

This building is class 2 listed A listed building in the United Kingdom is a building that

has been placed on the Statutory List of Buildings of Special Architectural or Historic

Interest. It is a widely used status, applied to around half a million buildings.



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A listed building may not be demolished, extended or altered without special

permission from the local planning autho rity who typically consult the relevant central

government agency, particularly for significant alterations to th e more notable listed

buildings. Exemption from secular listed building control is provided for some

buildings in current use for worship, but only in cases where the relevant religious

organisation operates its own equivalent permissions procedure. Owners of listed

buildings are, in some circumstances, compelled to repair and maintain them and

can face criminal prosecution if they fail to do so or if they perform unauthorised

alterations.

In England and Wales the authority for listing is granted by the Planning (Listed

Buildings and Conservation Areas) Act 1990 and is presently administered by

English Heritage, an agency of the Department for Culture, Media and Sport, andCadw in Wales (where it is a devolved issue). Listed buildings in danger of decay are

listed on English Heritage's Buildings at Risk Register.

There are three types of listed status:

y Grade I: buildings "of exceptional interest, sometimes considered to be

internationally important".

y Grade II*: "particularly important buildings of more than special interest".

y Grade II: buildings that are "nationally import ant and of special interest".

There was formerly a non-statutory Grade III, which was abolished in 1970.

Additionally, Grades A, B and C were used mainly for Anglican churches in use ±

these correspond to Grades I, II* and II.

These grades were used mainly before 1977, although a few buildings are still listed

using these grades.



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F ounded: 1815 Closed

The following problems were identified from the outside of the building.

To the front of the building.

All of the window frames have bad wood rot would recommend full replacements.

y missing/ roof tiles

y Pointing need to be addressed many areas of missing cement.

y Damp can be seen from the outside suggesting the bricks are saturated.

y Chimney breast is also leaning over with poor pointing too.

To the side of the building.

y All of the window frames have bad wood rot would recommend full

replacements.

y Major settlement is occurring please see figure (3.0)

y Two large areas of damp please see figure (3.1)

To the rear of the building

y No gutter system, mould growing on walls due to rain water running down

face of walls. y Missing roof tiles.

y Doors rotted (need replacing)



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F ig (3.0) F ig (3.1)

The two major problems

(1) Pointing in poor condition

(2) Rotted timber window frames

As can be seen in figure (3.0) the pointing is in poor condition and is in need of repair

below is bespoke specification for the repair work¶s.

Repointing walls

With exposure to wind, rain, frost etc, the mortar holding bricks (or stone) together onan external wall will often start to crumble away and fall out. On older properties, the

pointing will actually be a harder mortar than the bonding mortar, so once this is

dislodged, the softer bonding mortar will become exposed and wear away quite

quickly.

This sort of damage can take decades to occur but it is important to repair the

pointing as necessary otherwise water will increasingly penetrate and damage the

wall.

If the damage is limited to a smal l area, just that area can be repaired, however this

repointed area will tend to then stand out. Generally a whole wall face will have

weather in a similar way, so the whole wall will need repointing at the same time.

Repointing is time consuming to achieve a good overall appearance but is worth the

effort.



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Repointing above the height you can comfortably reach from ground level requires

scaffolding or an access tower, don't try to work from a ladder, it is uncomfortable

and unsafe.

C leaning out the old mortar

Work down the wall (this will avoid any debris falling on to areas which have already

been repointed), working on about 3 rows of bricks at a time.

On soft mortar use a hook or old screwdriver to rack out the old mortar, alternatively

use a plugging chisel and hammer start by taking out the vertical joints, then work

on the horizontal joints if you clear the horizontal joints first, you will risk chipping into

the brick above or below when you come to clear the vertical joints. Remove the old

mortar back to a depth of 8 to 12 mm from the front face at least equal to the width of the joints where the old mortar is loose beyond this depth, clean it back until fairly

firm mortar is located. Some old brickwork can have very narrow joints in places

where the hook or chisel is too wide, use a masonry saw, or hacksaw blade to

remove the mortar.

Make sure that the old mortar is removed from the top, bottom and sides of the

bricks so that the new mortar will adhere to them.

Any damaged or loose bricks should be replaced before proceeding with therepointing. When refitting such bricks, make sure that the new mortar bed is well

back from the front face so that they can be finished with the new repointing

The repointing mortar

The usual mortar for repointing is either a 6:1:1 mix of builders sand/hydrated

lime/cement or a 3:1 mix of sharp sand/hydrated lime. Measure the amounts

carefully so that each batch will set to a consistent colouring.

Only mix up a small amount of mortar at a time about half a bucket as repointing is

time consuming so you won't do a very large area before the mortar will start to go

off.



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The second problem repair/replace rotted timber window frames.

Window sills and frames are a frequent location of wood rot, because the exterior is

constantly exposed to the outdoor elements. In addition, leaking gutters or no gutters

cause rainwater to seep down into windows, which results in decay. Although woodrot is a serious problem if left unrepaired, many areas of wood rot are simple to

repair. Repairing rot in timber windows should be carried out as detailed below.

y Place a chisel against the area of rotted wood and tap it gently with a hammer

to dislodge as much of the decayed wood as possible. Continue the wood

removal until you reach healthy, yellow-coloured wood on all sides.

y Insert a 1/4-inch bit into a drill. Place the bit against the healthy wood and drill

1/2-inch deep holes into the wood that are spaced approximately 1 to 2 inches

apart.

y Use a dry paintbrush to brush away all wood dust and shavings from the

window for a clean surface.

y Open a bottle of liquid epoxy consolidant. Spread the liquid over the entire

surface of the wood, completely filling the holes with it. Allow the epoxy to dry

for five minutes and apply a second coat.

y Continue applying the liquid epoxy and waiting five minutes until the wood

stops absorbing the epoxy and a thin hard layer forms on top of the wood.

This strengthens the wood as well as provides a surface on which to complete

the repair.

y Open the epoxy filler and prepare it as directed by the instructions on the

packaging. Some epoxy fillers must be mixed with water, while others are

ready to use straight from the packaging. Scoop up some epoxy filler and

place it onto the window frame. Mold the putty with yo ur hands to fill in the

area of wood that you chiseled away. Use a putty knife to smooth the repair

so that it blends in with the shape and curvature of the surrounding frame.y Allow the epoxy filler to dry completely. Use the sandpaper to smooth any

edges and raised sections until it is indistinguishable from the surrounding

window.



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The second building to be surveyed.

33 Main Street, F ailsworth .

The second property to be surveyed is associated with the north of England most

especially, red brick terraced houses were built to accommodate factory workers

drawn to the cities by the Industrial Revolution, an early example of deliberately

affordable housing. Their distinctive style arises from the need for economy: small

size, red brick (cheap and quick to build with), sharing a chimney stack and scullery

wall, small panes of glass in the sash windows, slate roofs pitched low to save on

materials and a minimum of decoration. Typically the back door was used as the

main door, the front entrance being reserved for special visitors; but not all houses

had a back door, being surrounded by other houses on three sides. These homes

were packed closely together, and usually shared a washhouse and lavatory, coal

houses and work sheds. F igure 1.1 shows the front elevation of the surveyed

property.

F ig 1.1

Origins of the terraced house.

The terrace as a building style originated in Europe. In many cities terrace d housing

was favoured over the apartment building. The practice of homes built uniformly to

the property line began in the 16th Century and became known as "row" houses.



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"Yarmouth Rows" in Great Yarmouth, Norfolk is an example where applied to a

narrow street where the building fronts uniformly ran right to the property line.

The terrace style spread widely in the UK, and was the usual form of high density

residential housing up to World War II, though the 19th century need for expressiveindividuality inspired variation of facade details and floor -plans reversed with those of

each neighbouring pair, to off er variety within the standardised format. Post World

War II, housing redevelopment has led to many out dated or dilapidated terraces

being cleared to make room for tower blocks, which occupy a much smaller area of

land. Because of this land use in the inner city areas could in theory have been used

to create greater accessibility, employment or recreational or leisure centres.

However botched implementation meant that in many areas (like Manchester or the

London estates) the tower blocks offering no real improvement for rehousedresidents over their prior terraced houses.

With regards to the property surveyed at 33 Main Street, F ailsworth, Oldham the

following faults was identified;

Please use the following annex (2.0) and (2.0.1) which are attached to this report. As

a visual guide and layout of the surveyed property.

(1) To the rear of the property the extension needs all the roof tiles and gutters

and down pipes replacing.

(2) Major cracking to rear walls this will be down to settlement or failed

foundations (this will need further investigation).

(3) Gutters and down pipes to rear of property also need replacing.

(4) Spare bedroom floor as dropped my 100mm (th is will be down to either rotted

floor joists or movement to roof trusses but again this will need further

investigation.

(5) In the attic it can be seen that some roof tiles needs replacing as natural

daylight can be seen through the gaps which will allow rai n in, also there is no

roof felt in place at all, felt should be installed to prevent rain ingress and also

help insulate the property.



Brendan Miles


(6) Throughout the property it is noted that the ceilings decorations are of illegal

polystyrene tiles, which in the event o f a fire would melt on any occupants

within the property.

(7) The property as no heating system this will need to be addresses by a Corgi

or Gas Safe heating engineer.

(8) The property also needs a full electrical test to be carried out by a NIC -EIC

approved contractor.

The 2 major defects

(1) Possible unsupported chimney breasts see fig (1.1) and (1.2)

(2) Major settlement to rear of property please see fig (1.3)

Within the property it can also be observed that the fireplace in kitchen and

living room as been covered up with plasterboard and skimmed but there is a

noticeable cracking to the plaster, this would suggest that no steel support

system has been used to support the chimney breast. ( F urther investigations

should be carried out to inspect the stability of the chim ney breast). Please

see figure 1.2 and 1.3

F ig 1.2 Kitchen chimney F ig 1.2 Room C himney

Problem 2, settlement to rear of property,

As can be seen from figure (1.3) the rear of the property as major subsidence and

should be addressed in the near future.

F ig (1.3) Subsidence to rear of property.



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W hat is subsidence

Subsidence happens when the ground beneath a property moves or sinks

downwards, causing the foundations of the building to move. The most common

sign is the appearance of cracks in the walls of the building, although it's

important to note that not all cracks mean subsidence.

It is important to look out for small, diagonal cracks that can appear suddenly in

brickwork or plaster, inside our out, especially after long periods of dry weather.

They often appear around windows and doors and are wider at the top than the

bottom. Windows and doors may start to stick when you try to open or closethem. F loors may also look uneven or distorted which as occurred within the

spare bedroom to the rear of th e property please see annex 2.0.

W hat causes subsidence

(1) Some soils, particularly clay can cause subsidence. As the soil dries up and

shrinks, or absorbs water and expands, this can cause movement in the

foundations.

(2) Trees and other vegetation, larger trees especially take moisture from the soil

making it shrink. Roots can grow longer in search of more moisture. Some

types of tree are more likely to cause subsidence than others, due to the size

they grow to and the root structure, these include willows, oaks and elms.

(3) Water damage ± as a result of burst water pipes or other leaks may cause

subsidence by washing away soil from under the house.



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(4) Location, this is less common, but when a house has been built on land that

has been, or is close to an area that has been mined in the past .

Repairing subsidence

As listed above there are a number of factors that can cause subsidence such as the

property may be built over an old mine shaft or a mains water pipe as burst under

the property. The most common cases of subsidence is down to large trees close to

the property by calling a suitable tree surgeon this will stop the problem from getting

any worse.

However in the case of the surveyed property no noticeable culprit to the problem

can be identified. I would suggest having a further investigation carried out by a

structural engineer. I would suspect the foundations need underpinning which is veryexpensive works. Please see annex 3.0 I have included to give a detailed guidance

on underpinning.

Produce façade maintenance and repair schedules for one of the buildings.

You should prioritise the repairs required and justify your selection.



Brendan Miles


Good Maintenance,

Part of any building¶s maintenance plan should include protecting it against its

enemies, repairing any damage and maintaining the building exterior on a regular

basis. Neglecting the outside of the building can lead to worse ning conditions.

It is important to schedule regular inspect ions and maintenance to prevent problems

such as leaks, cracking and crumbling turning into an expensive rebuild.

Understanding what kind of damage a building's facade is most vulnerable to

depends on knowing what the structure is made of.

No matter what the material, however, the number one factor that can ruin any type

of facade is water.

Water intrusion and insufficient drainage can pose a potenti al threat to the durability

and usability of residential construction.

All masonry absorbs water, if a building absorbing water in cold climates and then

freezes it will damage the masonry and begin to crack.

Once water gets into the building, it¶s destructive. Wet or damp drywall, caulking,

grout, wood, or carpet can become mouldy. When the mould is disturbed, spores are

released into the air. When inhaled, mould spores can cause serious health damage.Water can also cause the facade to crumble and crack.

Inspections

Maintaining any type of façade first requires a full inspection by a qua lified

professional to look for potential sources of water infiltrat ion.

There are several ways that these inspections can be made,Initial inspections can be

made from the ground using binoculars or a camera as well as from rooftops and

windows or balconies of adjacent buildings.

Repairs



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As time passes, brick walls begin to look tired and worn. One reason is that rain

water is probably getting inside the cement between the bricks, which holds them

together. In the winter, as the frosts begin to bite, the wet area inside the wall

freezes. As we know, when water freezes, it expands and causes the cement to

break up, and it begins to crumble. The end result is the tired and worn appearance.

Gradually, the cement breaking up reduces the amount of bond it had on the bricks,

and so the bricks may begin to break up around its edges. When that starts to

happen, it is just a matter of time before the whole lot is looking in need of attention.

The danger then is that the wall is becoming an unsafe structure.

Not only does the mortar mix make the brick waterproof, but each layer of bricks

support the row of bricks above it. The first j ob to be done, to stop the rain water

from getting into the brick joints, is to re-point the wall.

This not only makes the wall waterproof, but of course it gives the wall its strength. It

is best to do pointing jobs on a day when the weather is dry, otherwise the strength

of the cement may be compromised. If the wall is badly stained, like an iron nail in

the wall, there are different methods to choose from to clean the bricks up.

One way is to go over the bricks with a wire brush until the stain has disappeared,

another way is to sand blast it away, and the third way is to brush on a liquid cleaner

that bubbles away, removing the stain. Care must be taken with all cleaning

methods, eye goggles and a breathing mask is vital.

If you are not sure on the way to start the job, always ask someone who does know,

how to do the job. As bricks age, the form a kind of glaze on the outside, that is it's

weather protection. Once that is damaged heavy rain can get in the brick, and the

frost problem comes back.

A properly maintained brick wall, whether it is a part of a building, or simply a wall in

the garden, should last in excess of 100 years. If you find that a brick has broken up

in the wall, through a weakness or damaged by having nails driven into it, the bri ck

must be replaced.

That can be quite easily, using a suitable chisel, you just tap away until all of the

broken pieces are removed. To replace with another brick that looks in good



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condition, first put in an amount of mortar in for the brick to sit on, t hen force in more

mortar over the top and sides of the brick, give it a day to harden, then if it is needed,

force in more mortar to finally make a seal to withstand the rain.

After the brick work and pointing as been repaired it is also important to re-caulking joints around windows, doors and other penetrations.

References



Brendan Miles


h ttp://www.diydata.com/tec hniques/brickwork/repointing_walls/repointing_walls.p hp

F ryer, B., (2006). The Practice of C onstruction Management. Blackwell PublishingLtd Oxford, London

Project Management Body Of knowledge (Third Edition)

Emmitt, S., (2010). Introduction to C onstruction of Buildings. Wiley-BlackwellChinchester, West Sussex.

http://wiki.answers.com/Q/The_various_stages_of_the_construction_process

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