ff conference 2013 - life of a building

8/11/2019 FF Conference 2013 - Life of a Building

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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 againststorm 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.


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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


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What effects the life of buildingmaterials

There are a large number of environmental and chemical factors whichcan 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


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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


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Warranty life, Design life and Real life


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Domestic Building Terms

1 Chimney stack

2 Flashing

3 Ridge4 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 tank15 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 pipe24 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 sewer35 Interceptor trap


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Commercial -Portal Frame Building


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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


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Policy Exclusions ( continued )

gradual causes including

deterioration or wear and tear

inherent vice latent defectgradual 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


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Cross section of a flat roof


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Flat roof - Common problems

Age related cracking

Gravel slippage


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Flat roof even more problems

Blisters

Ponding


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Felt Roof Failure


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Felt Roof Failure


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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 25years plus ??

Ballasted


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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


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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


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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


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Defective Chimney Stack


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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


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Rafters

Purpose

To support roof covering

Common Issues

Inadequate size sagging

Roof leaks and condensation

Lack of Straps


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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


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Condensation/Mould in Roof

Increased Insulation

Eaves are blocked with Insulation

Breathable feltTyvek

Potential Issues

Build of moisture can rot timbers or

cause water ingress damp into

rooms

L ki G tt


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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 causefailure


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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


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Air Bricks

Allows air to circulate under timber

floors

Potential Issues

If blocked air cannot circulate

causing rot

Flood waters will enter


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Drains

Pipes can be of various materials clay ,pitch Fibre or Plastic

Potential Issues

Pitch Fibre limited life span and collapseover time

All pipes can get blocked and cause

backing up

Other drains leak which can cause other

problems


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Ground Floor


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Sulphate attack

Moisture from general waterin ground can cause sulphate

attack .

Regional variations on risk

Potentially Insured peril but

possible gradually operating

cause


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Basement

Converted to habitable rooms with no

proper damp proofing

Potential Issues

Flooding / Rising Water tables Escape of

water causes water ingress.

Gradually Occurring ?


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Modern Timber frame

St d Partition Wall


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Stud Partition Wall


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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


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Plaster finish

Most common surface in do, Various types:Browning plaster,

Bonding plaster,One-coat plaster, LimePlaster, Finishing plaster

Potential Issues

Susceptible to movement and will easily

crack .

Flood or escape of water will cause salts toeffervescence causing paint to flake off

Lath and Plaster Ceiling


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Lath and Plaster Ceiling

Used up to 1950s. 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


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Render

Render is used as finishing coat onstone 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

External Render


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TyroleanPebble Dash

External Render


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Fl J i


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Floor Joists

Structural members supporting floorboards / chipboard floor

Potential Issues

Joists twist if not adequately braced

End of joist can rot if exposed to water -

End treated / separated from moisture

I d b W t P il ??


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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 coursestypes and performance - Control of rising damp and re-plastering Condensation - Condensation -v- other sources of dampness-

Dry Rot/ Wet Rot


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Dry Rot/ Wet Rot

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

Li t l


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Lintel

Purpose to support wall overModern lintels are metal or concrete ,

Older ones timber

Common Issues

Timber rots and twist

Metal rusts

Concrete spall

Lif f M t i l R fi C t


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Life of Materials- Roofing Components

Lif f M t i l W ll / Wi d


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Life of Materials- Walls / Windows

S


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Summary

Review actual policy exclusion wording

Look carefully at whether damage would have occurred but for theinsured peril operating

Further sources of info

Internet

BRE

Local Surveyors


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Questions ????

ff conference 2013 - life of a building

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