Moisture and Biodeterioration Risk of Building Materials ... · Moisture and biodeterioration risk...

Moisture and biodeterioration risk ofbuilding materials and structures

Hannu Viitanen1, Juha Vinha2, Kati Salminen2,Tuomo Ojanen1, Ruut Peuhkuri1,

Leena Paajanen1, Kimmo Lähdesmäki2

1 VTT, Technical Research Centre of Finland, Espoo, Finland

2 Department of Civil Engineering, Tampere University of Technology, Tampere, Finland.

VTT TECHNICAL RESEARCH CENTRE OF FINLAND

Ageing / biodeteriodation / damages

•During the service life of buildings, natural ageing of materials due to different chemical, physical, and biological processes can take place.

•Grey wood is a normal phenomenon in outside conditionson untreated wood (caused partly by discolouring fungi)

•In damage cases, more severe changes of material are associated (mould growth, decay, insects plants, animals)

2


Mould and decay in buildings

•Level and duration of moisture stress connected with temperature are the most critical factors for the durability of building materials and decay.

•Mould fungi, algae and lichens grow on the surface of many materials, e.g. textiles, leather, coatings, paper, wood, plastics, brickwork and concrete.


Loads on a building during the service life

humidity, temperature, material, time period, organisms

Moisture stress Ageing

4

MOISTURE DAMAGE tolerances are overloaded

MOULD

RH: > 75 95 % Temp: 0 55 C Time: d, w, m

DECAY

RH: > 90 95 % Temp: 5 50 C Time: w, m, y

Detection the damages and simulation the causes of problems

Indoor


Organisms causing problems in different building components

Attics: mould, bluestain, insects

Facades: mould, bluestain, algae, lichens(decay: Gloeophyllum,Dacrymyces)

Balconies, fences, terraces: algae, lichens,mould, blue stain, decay:Gloeophyllum, Coniophora,Leucogyrophana etc, insects

Wood in ground contact orwater damages: soft rot, white rot, bacteria, brownrot: Poria, Serpula etc, insects,

5


Problems in different part of building (1)

•Wet rooms: Water penetration through inside surface or pipe leakage High indoor humidity Connected with other problems in building envelope

6


Problems in different part of building (2)•Floors and lower parts of walls:

Moisture transport (capillary or diffusion), evaporation from the ground and water condensation high humidity and condensation in cold ventilated basement

wooden beams on uninsulatedconcrete slab in ground

pipe leakage and other water damages lower part of wall in ground contact

Typical organisms: Several types of mould and decay fungiBacteriaInsectsTermitesAnimals

7


Facades, claddings and fences: Problems in different part of building (2)

High weathering risk, building near open waterfront, driving rain, wood partly in ground contact, critical structure of details (water accumulation and sink), different type of defects

Typical organisms: Mould and blue stain fungi Gloeophyllum trabeum, Antrodia serialis Insects, rodents

8


Wood in ground contactor water damage of building

•Typical organisms: Dry rot fungus Poria placentaConiophoraputeanaLeucogyrophanaBacteriaDifferent soft rotand white rot fungiMould fungi

•Insects

•Termites

•Animals

9


A building is an individual and whole unit•service life and durability aspects of materials, building components and

buildings: intended use condition / damage condition

•environment, exposure and use conditions, design, construct, maintenance and repair of a building with overall functionality in mind

•simple, clear operating instructions and service

•preventive maintenance and repair •cooperation of different parties (experts of the building field, health and

building authorities and biology experts) •clear definition and concept of different problems and limit states:

> mould growth > decay development > damages > accepted functions of different building components > safety and security

•performance degree and limit states

•overall function / details: testing function of the components > worst case scenario / natural conditions

10


Service life, ISO 15686

SL of whole structure / details

moisture acumulation in details > critical also for the whole structure

testing of details > laboratory scale > worst case scenario for "wrong details"

Building perfromance life cycle

Operation over time Q

ualit

y / F

unct

ion

PD 0

PD 2

PD 3

PD 4

PD 1

Performance without preventive actions

Replacement

Maintenance

Repair Refurbishment

Aging / Failure

reparation of details ?

mould model is a tool Building performance life cycle as a

for evaluate lower function of quality, performance degree

exposure condtions (PD), failure, maintenance, refurbishment, repair and replacement (ISO 156867).

separete decay models

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12


Organisms involving damages and defects ofbuilding components [Viitanen and Salonvaara 2001]

Organism Damage / problem type Humidity or moisture range (RH or MC %)

Temperature range (�C)

bacteria biocorrosion of many different materials, smell, health problems

wet materials RH > 97 %

ca 5 to +60

mould fungi surface growth on different materials, smell and health problems

Ambient RH > 75 %, depends on duration, temperature and species

ca 0 to + 50

bluestain fungi

bluestain of wood permeability change of wood

Wood moisture content > 25 120 %, RH > 95 %

ca 5 to + 45

decay fungi different type of decay in wood (soft rot, brown rot or white rot), also many other materials can be deteriorated, strength loss of materials.

Ambient RH > 95 %, MC > 25 120 %, depends on duration, temperature, fungus and materials

ca 0 to +45

algae and lichen

surface growth of different materials on outside or weathered material.

wet materials also nitrogen and low pH are needed

ca 0 to +45

insects different type of damages in organic materials, surface failures or strength loss.

Ambient RH > 65 % depends on duration, temperature, species and environment

ca 5 to +50


Criticalconditions

for mould(weeks)

and

decay(months)

on pinesapwood

13

70

75

80

85

90

95

100

0 5 10 15 20 25 30 Time (weeks)

RH

(%)

1 °C 5 °C 10 °C 20 °C

70

75

80

85

90

95

100

0 4 8 12 16 20 24

Time (months)

RH

(%) 0 °C

5 °C 10 °C 20 °C


MATHEMATICAL MODELING OF MOISTURE BEHAVIOUR ANDMOULD GROWTH IN BUILDING ENVELOPES

5/2005 –12/2008

Project team

•TTY: Kati Salminen, Juha Vinha (project leader), Kimmo Lähdesmäki, Tomi Strander

•VTT: Hannu Viitanen, Tuomo Ojanen, Ruut Peuhkuri, Leena Paajanen, Hanna Iitti, Liisa Seppänen

•Industrial partners

14


TEST MATERIALS

Insulation materials

Glass wool Polyester wool EPS PU Stone materials

Concrete Autoclaved aerated concrete Expanded clay aggregate concrete

Wood materials Edge glued spruce board Pine sap wood (reference)

This study concentrates on materials and conditions which have not been tested or discussed in earlier studies.

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16


MATERIAL EXPERIMENTS IN LABORATORY

97% RH / 20°CConstant 90% RH / 5°CConstant 90% RH / 22°CConstant 97% RH / 5°CConstant 97% RH / 5°CConstant

50% RH / 22°C97% RH / 22°CCycle 4 –8 weeks



97% RH / 22°CConstant

Test condition 2 Test condition 1 Constant/cyclical conditions


RH 97%, +22 C

Spruce Glulamin Pine Sapwood Mineral Wool Paper of PUR Concrete

Response of some building material to mould growth at RH

0

1

2

3

4

5

Mou

ldin

dex

(05

)

97 –98 % / 22 °

Surface subjected to mould suspension

0 8 16 24 32 40 48 56 64 72 80 88 96 104

Weeks

RH 97%, +22 C


5

Mou

ldin

dex

(05

) 4 Surface without added 3 mould suspension

2

1

0

0 8 16 24 32 40 48 56 64 72 80 88 96 104

Weeks 17


RH 90%, +22 C


Mou

ldin

dex

(05

) M

ould

inde

x (0

5)


5,0

4,0

3,0

2,0

1,0

0,0

0 8 16 24 32 40 48 56 64 72 80 88 96 104

Weeks

RH 90%, +22 C

5,0

4,0

3,0

2,0

1,0

0,0

0 8 16 24 32 40 48 56 64 72 80 88 96 104

Weeks

Response of some building material to mould growth

at RH c.a. 90 % / 22 °C

Surface subjected to mould suspension

Surface without added mould suspension

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MATERIAL EXPERIMENTS IN FIELD CONDITIONS

19


STRUCTURE EXPERIMENTS IN LABORATORY

Cooling units

Heaters

Evaporator

Evaporator Structure to be tested

Sprinklers and radiation heaterd

INSIDE OUTSIDE

concrete + expanded polystyrene concrete + polyester wool

concrete + polyurethane concrete + glass wool

expanded clay aggregate concrete + expanded polystyrene

expanded clay aggregate concrete + polyester wool

expanded clay aggregate concrete + polyurethane expanded clay aggregate concrete + glass wool

edge glued spruce board + expanded polystyrene edge glued spruce board + polyester wool

edge glued spruce board + polyurethane edge glued spruce board + glass wool

light concrete + expanded polystyrene light concrete + polyester wool

light concrete + polyurethane light concrete + glass wool

Second test series First test series

Detected interface

20


STRUCTURE EXPERIMENTS IN LABORATORY

Lämpötila tutkittavassa rajapinnassa RH tutkittavassa rajapinnassa

30.00 100.00

90.00 25.00

80.00

20.00

70.00

15.00

Temperature 60.00 RH

10.00 50.00

40.00 5.00

Concrete Glass wool 30.00 Edge glued spruce board Glass wool 0.00

5.7.2006 24.8.2006 13.10.2006 2.12.2006 21.1.2007 12.3.2007 1.5.2007 20.00

5.00 610.006

M glass wool 0.00 M glass wool

10.00 5 M concrete 5 5.7.2006 24.8.2006 13.10.2006 2.12.2006 21.1.2007 12.3.2007 1.5.2007 Kevytbetonimuovikuitu Kevytbetonilasivilla Ksbetoni muovikuitu Ksbetoni lasivilla M edge glued spruce board

Kevytbetonimuovikuitu Kevytbetonilasivilla Ksbetoni muovikuitu Ksbetoni lasivillaBetoni muovikuitu Betoni lasivilla Kuusi muovikuitu Kuusi lasivilla

4 4 Betoni muovikuitu Betoni lasivilla Kuusi muovikuitu Kuusi lasivilla

3 3

2 2

1 1

0 022.6.2006 11.8.2006 30.9.2006 19.11.2006 8.1.2007 27.2.2007 18.4.2007 7.6.2007 2122.6.2006 21.8.2006 20.10.2006 19.12.2006 17.2.2007 18.4.2007 17.6.2007 16.8.2007


STRUCTURE EXPERIMENTS IN FIELD CONDITIONS

mould index = 0after 6 months

RHinterface = 60 70% or 80 90% (gw, pw)

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Modelling the mouldCriteria for mould growth

Generally, the models are

•based on measured data

•regression analysis

•isopleths

•implementation of hygrothermal calculation principles on mould spores!

•isopleths and models are based on laboratory results of test using different mould fungi and different growth medium at regulated humidity and temperature conditions

[Clarke et al 1999] [Sedlbauer & Krus 2003]23


C C o n s ta n t R H Predicted mould growth 6

1 2 /1 2 h 9 7 /7 5 R H

on pine sapwood indifferent varied

exposuresat RH 97 % and 75 % M

ould

inde

x 5

4

3 6 /1 2 h 9 7 /7 5 R H

2

(VTT model) 0

1 3 / 2 1 h 9 7 /7 5 R H

0 2 8 5 6 8 4 1 1 2 1 4 0 1 6 8 1 9 6

T im e (d a y s )

D 7 /1 4 d 9 7 /7 5 R H 6

3 /4 d 9 7 /7 5 R H Decline of the 5 mould index during 4

3 dry periods 7 /2 3 d 9 7 /7 5 R H

2 1 /6 d 9 7 /7 5 R H

1 6 /4 2 h 9 7 /7 5 R H

0 0 2 8 5 6 8 4 1 1 2 1 4 0 1 6 8 1 9 6

T im e (d a y s ) 24

Mou

ld in

dex


Measured climate for the material tests in field conditions

Measured climate data in Tampere experiments 30 100

25 90

20 80

15 70

10 60

T, o C

5 50

0 40

5 30

10 2048 per. Mov. Avg. (T) 15 48 per. Mov. Avg. (RH %) 10

20 0

0 5 10 15 20 25 30 35 40 45 50

Weeks (June 22 May 2)

% R

H

25


Comparison of VTT model (Viitanen) andWufiBio (Sedbauer)

0

1

2

3

4

5

0 5 10 15 20 25 30 35 40 45 50 Weeks (start June 22.)

Mou

ld g

row

th in

dex

MO

0

50

100

150

200

250

300

350

400

450

500

Wuf

iBio

gro

wth

, mm

Viitanen, normal decline Viitanen, no decline Measured (top) Measured (low) Viitanen, Espoo climate WufiBio, class 1

Comparison of Viitanen model and WufiBio results

Solution using Tampere climate data and TCCC2D simulations of

T, RH and Mo fields

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Calculation case: Construction

Construction from outside:

Jyväskylä weather

exterior sheating ventilated air cavity 12 mm wood chip board 150 mm mineral wool 12 mm gypsum board

inside difusion resistances: Sd = 0 m, 1 m and 3 m

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Critical boundary


Prediction of mould growthInfluence of diffusion resistance of vapor barrierVTT model (pine sap wood) vs. WufiBio (LIM I)

28

0

1

2

3

4

5

6

0 4 8 12 16 20 24 28 32 36 40 44 48 52

Weeks (start Oct. 1)

Mou

ld g

row

th in

dex

Mo

Sd,in = 0

Sd,in = 1 m

Sd,in = 3 m

0

100

200

300

400

500

600

700

800

0 4 8 12 16 20 24 28 32 36 40 44 48 52 Weeks (start Oct. 1)

Gro

wth

, m

m

Sd,in = 0

Sd,in = 1 m

Sd,in = 3 m

WufiBio growth prediction curves


30 Seinäkoe: Kevytbetoni lasivilla 100

25 95 Conditions on the 20 90

evaluated surface in 15 85

RH

, %

element componentsin the laboratory: light

10 80

5 T. 75 RH concrete + glass wool0 70

5 65

10 60 5.7.06 3.9.06 2.11.06 1.1.07 2.3.07 1.5.07 30.6.07 29.8.07 28.10.07

pvm

T, C

30 Seinäkoe: Kevytbetoni lasivilla 100

25 95

20 T. 90

RH 15 85

10 80

5 75

0 70

5 65

10 60 23.5.07 2.6.07 12.6.07 22.6.07 2.7.07 12.7.07

pvm 29

T, C

RH

, %


Development of mould on light weight concrete

30

0

1

2

3

4

5

6

5.7.06 3.9.06 2.11.06 1.1.07 2.3.07 1.5.07 30.6.07 29.8.07 28.10.07

pvm

Hom

eind

eksi

KBet laskettu

Mitattu Kbet

Mänty ref, laskettu.

Kevytbetoni lasivilla seinäkoe, mittaukset ja laskenta


Decline of the mould developmentH

omei

ndek

si

4,0

3,5

3,0

2,5

2,0

1,5

1,0

0,5

0,0

Kevytbetoni lasivilla seinäkoe, mittaukset ja laskenta

KBet laskettu

Mitattu Kbet

KBet laskettu Ei taantumista

5.7.06 3.9.06 2.11.06 1.1.07 2.3.07 1.5.07 30.6.07 29.8.07 28.10.07 pvm

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We thank for the financing:•TEKES

•VTT

•Industrial partners

Thank you for your attention !

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Moisture and Biodeterioration Risk of Building Materials ... · Moisture and biodeterioration risk...

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Transcript of Moisture and Biodeterioration Risk of Building Materials ... · Moisture and biodeterioration risk...