The Life of a Building

John Parvin, Major Loss Team Manager, Zurich

• What buildings are designed to do and what is the expected level of resilience of a building against

storm and flood etc.

• How buildings deteriorate over time

• Common examples of gradually operating causes.

• Types of materials found in a building and their typical timescales for deterioration.

What buildings do?

• Keep the weather out?

• Provide a home ?

• Make money for architects and contractors?

• Walls to hide behind? Display wealth or good taste?

• Sites for productive labour and entertaining leisure?

• Establish ownership?

• Prevent some people from coming inside? Prevent others from leaving?

• Buildings stabilize social life.

But buildings and their elements do wear out

What effects the life of building materials

There are a large number of environmental and chemical factors which

can affect the durability of a material or component during its service life.

These include the following:

• Moisture

• Humidity

• Temperature

• Driving wind and rain

• Chemical pollutants

• Solar radiation

• Site conditions.

Use of the Building

Guidance on Building defects

• Inappropriate use of materials

• Use of material adjacent to another which adversely affects it

• Lack of knowledge by designer

• Building being subject to forces or agents unknown at design stage

• Inaccurate info from manufacturers

• Poor quality manufacturer

• Poor workmanship

• Lack of routine maintenance

Durability -Main Materials in Buildings

• Bitumen materials : felt , liquid coatings, asphalt

• Bricks and tiles : mostly clay and concrete some bricks calcium silicate

( sand lime bricks )

• Concrete

• Metals- copper , ferrous , lead and zinc

• Plastics

• Stone - limestone and sandstone

• Timber – softwood and hardwood

Warranty life, Design life and Real life

Domestic Building Terms

1 Chimney stack

2 Flashing

3 Ridge

4 Purlin

5 Slating or tiling

6 Hip

7 Felt and battens

8 Strut

9 Insulation

10 Electrical conduit/wiring

11 Soil and vent pipe

12 Cold water storage tank

13 Vent pipe with wire balloon

14 Central heating header tank

15 Rafters

16 Timber stud wall

17 Floor joists

18 Felt with stone chippings or reflective

paint

19 Cement rendering

20 Overflow pipe through wall

21 Hot water cylinder

22 Cavity brick (or block) wall

23 Gutter and rainwater pipe

24 Concrete or steel lintel over opening

25 Supporting steelwork

26 Water main within ground

27 Damp proof course

28 Air brick

29 Wall ties

30 Gulley with grating

31 Solid wall

32 Floor joists

33 Surface water to soakaway

34 To main sewer

35 Interceptor trap

Commercial -Portal Frame Building

Damage caused by wear and tear,

atmospheric or climatic conditions

(other than storm or flood), rot, fungus,

insects or any gradual cause.

Policy Exclusions

wear and tear, the action

of light or atmosphere,

moths, vermin or insects

corrosion, dampness,

dryness, wet or dry rot,

marring, or

scratching

Policy Exclusions ( continued )

gradual causes including

deterioration or wear and tear

inherent vice latent defect

gradual deterioration wear

and tear frost change in water

table level its own faulty or

defective design or materials

corrosion, dampness, dryness,

wet or dry rot, marring, or

scratching

Financial Ombudsman

• Drains – Accident in slow motion

• Water ingress into basements and cellars

– FOS view that a flood does not have to be a sudden and violent

event. “flooding can happen where water enters (or builds up in) a

property slowly and steadily”

– basement room – that was watertight before – has started to let water

in, and the insurer says that the damage was caused by failed

tanking – and that the tanking had failed because of wear and tear

and/or lack of maintenance. Fos view e say that the cause of the

damage was flood – not the failure of tanking

• Build up of snow

Examples of Moisture Sources

Roof Leak

Defective

Flashing Uncapped

Chimney

Condensation from

Flues Plumbing

Leak

Rising

Damp

Condensation

Leak from

Services

Defective

Guttering

Defective

Pointing/

rendering

Spillage

Ground Moisture

Defective

Drainage

High Ground

Levels

Flat roof

Typically found on single storey

extensions and many types of

commercial building

Common Issues

Lack of fall

Solar radiation

Thermal Movement

Poor workmanship

Cross section of a flat roof

Flat roof - Common problems

Age related cracking

Gravel slippage

Flat roof – more common problems

Splits

Pooling of

water

Flat roof – even more problems

Blisters

Ponding

Felt Roof Failure

Felt Roof Failure

Single membrane Roof Systems

Mechanically

fixed

Adhered

Single ply membranes are strong.

Used on large flat roof areas ,

they form complete, durable roof

systems. Typical products are

Sarnifil, Bauder

Problems Defects

in installations / design

Lifespan

Warranties 15 years . Life span 25

years plus ??

Ballasted

Asbestos Cement Roof

Use

Older Properties Garages and industrial

Buildings

Modern equivalent cement composite

Common Issues

• Brittle

• Too Shallow a pitch

• Brittle

• Rusting Fixings

• Inadequate support

Thermoplastic roof sheets

Use of Flash Band

Conservatory roofs

Used at joints and at junctions instead of

lead

Thermopastic Sheets Substitute for glass

Common Issues

-

Thermal movement ultraviolet light

Becomes Brittle

Flashband – inadequate primer

Step Flashing

Lead stepped flashing makes

water proof joint at junction of

chimney/ dormer window.

Soakers under flashing

Possible Problems

Roof might drop exposing

soakers

Flashing Pulls out

Lead perishes over time

Cement Fillet – Chimney

Purpose

The sand cement fillet is placed

around the base of the chimney

rather than lead

Common Issues

The cement haunching cracks and

is susceptible to water ingress and

frost damage

Water enters between stack and

tiles

T

Defective Chimney Stack

Felt and Battens

Purpose :

The felt is a secondary defence to water .

Common Issues

Water penetrates the slates/ tiles at verges

/ eaves valleys etc –Overtime this will

cause rot to the battens and felt

Valley – Battens installed incorrectly

Rafters

Purpose

To support roof covering

Common Issues

Inadequate size – sagging

Roof leaks and condensation

Lack of Straps

Purlins

Purpose

To provide support to rafters

Common Issues

Very often inadequate size to

support weight of rood .

Particular problems with older

roofs when covering changed

Condensation/Mould in Roof

Increased Insulation

Eaves are blocked with Insulation

Breathable felt – Tyvek

Potential Issues

Build of moisture can rot timbers or

cause water ingress damp into

rooms

Leaking Gutter

Gutter formed from Plastic ,

Cast Iron , Asbestos

Common Issues

Joints fail Thermal

movement . Cast Iron rust

Gutters leak causing water

ingress

Weight of snow can cause

failure

Suspended Timber Floor

Wall plate supported suspended

timber floor

Sleeper walls

Common Issues

Lack of ventilation causes damp

Flood or escape of water can

cause rot if not dried adequately

Air Bricks

Allows air to circulate under timber

floors

Potential Issues

If blocked air cannot circulate

causing rot

Flood waters will enter

Drains

Pipes can be of various materials clay ,

pitch Fibre or Plastic

Potential Issues

Pitch Fibre limited life span and collapse

over time

All pipes can get blocked and cause

backing up

Other drains leak which can cause other

problems

Ground Floor

Sulphate attack

Moisture from general water

in ground can cause sulphate

attack .

Regional variations on risk

Potentially Insured peril but

possible gradually operating

cause

Basement

Converted to habitable rooms with no

proper damp proofing

Potential Issues

Flooding / Rising Water tables Escape of

water causes water ingress.

Gradually Occurring ?

Modern Timber frame

Stud Partition Wall

Stud Walls/ Timber Framed

Typical timbers with plasterboard

Some modern building metal studs

Common Issues

Excessive moisture will cause twisting ,

warping and possible rotting

Insulation contaminated following flooding

Plaster finish

Most common surface in do, Various types

:Browning plaster,

Bonding plaster, ‘One-coat’ plaster, Lime

Plaster, Finishing plaster

Potential Issues

Susceptible to movement and will easily

crack .

Flood or escape of water will cause salts to

effervescence causing paint to flake off

Lath and Plaster Ceiling

Used up to 1950’s. Wooden

lathes nailed to ceiling or wall

studs . Each lathe spaced

and filled with plaster

Potential issues

Overtime due to thermal

expansion and construction

the plaster debonds and loses

its key

Render

Render is used as finishing coat on

stone and block work

Potential Issues

Debonds from substrate over a period

of time .

In new build inappropriate mix

It will sound hollow if tapped

Water penetration and frost

Tyrolean Pebble Dash

External Render

Chipboard Decking

Originally used on roof decks

and on floors .Shredded wood

held together with glue .

On roof decks now use ply or

OSB

Potential Issues

Warps or disintegrate when it

becomes wet

Floor Joists

Structural members supporting floor

boards / chipboard floor

Potential Issues

Joists twist if not adequately braced

End of joist can rot if exposed to water -

End treated / separated from moisture

Issues caused by Wet Perils??

• Wood rotting fungi:

• - Dry rot (Serpula lacrymans)

• - Cellar fungus (Coniophora puteana)

• - Control of rot.

• - Other fungi in buildings

•

• Rising damp:

• - Presence and features/heights of rising damp

• - Remedial damp-proof courses – types and performance

• - Control of rising damp and re-plastering

•

• Condensation

• - Condensation -v- other sources of dampness-

Dry Rot/ Wet Rot

Dry rot (Serpula lacrymans) Wet Rot (coniophora puteana)

Lintel

Purpose to support wall over

Modern lintels are metal or concrete ,

Older ones timber

Common Issues

Timber rots and twist

Metal rusts

Concrete spall

Life of Materials- Roofing Components

Life of Materials- Walls / Windows

Summary

• Review actual policy exclusion wording

• Look carefully at whether damage would have occurred but for the

insured peril operating…

• Further sources of info

– Internet

– BRE

– Local Surveyors

Summary

• Discard preconceptions.

• Adopt a systematic approach.

– Collect all available relevant data

– Marshal the facts

– Observe the chronology

– Distinguish opinion from observation.

• Correct diagnosis provides a proper basis for policy interpretation

Questions ????