HHSRS VERSION 2

SPETEMBER 2004

DAMP AND MOULD GROWTH

HHSRS VERSION 2

Yes

Yes

No

No

Vulnerable age

Related hazards

A) Front end bedroom

Persons aged under 15 years

Excessive cold

B) Bathroom

Multiple locations

Secondary hazards

DESCRIPTION OF HAZARDS

Dwelling: 1960s, 2⁄3rd floor 3 bedroom end maisonette

Background: The 4 storey block is of brick crosswall and exposed concrete floor slab construction. Space heating

to each maisonette is by means of a gas-fired ducted warm air system.

Front bedroom: The concrete floor to the top floor front bedroom and bathroom projects over the access balcony by

approximately 1 metre. There is damp affected plaster and mould growth to the front main walls and to the exterior

flank wall to the front bedroom.

Bathroom: The front wall of the bathroom and adjacent ceiling and internal walls are affected by severe and

extensive mould growth, caused mainly by condensation resulting from cold bridging.

A)

B)

LIST OF RELEVANT MATTERS

LIKELIHOOD & OUTCOMES

A

B

-

-

3

3

3

-

3

-

-

-

-

-

A

B

1

2

3

4

a

b

c

d

e

f

g

h

Rising damp

-

Penetrating damp

-

Condensation

3

Mould growth

3

Energy efficiency

3

Background ventilation

-

Extract ventilation

Clothes drying facilities

-

Damp proofing

-

Disrepair

-

Exposed water tanks etc

-

Water using appliances

-

-

-

I

Plumbing⁄waste pipes

j

Rain water goods

k

Roof⁄sub-floor spaces

l

Small room sizes

# Secondary hazards

-

None

-

-

-

-

-

A

-

B

-

-

Key

3

Seriously defective

2

Defective

1

Not satisfactory

-

Satisfactory⁄NA

8

Improved

Score:

Av:11

The problems in the dwelling are mainly due to the cold bridges created by the exposed

ends and ceiling of the reinforced concrete slab forming the top floor to the block. Installing

insulated cladding and a better heating system would reduce the risk to better than average

levels.

Justification

NEW RATING

Av: Nos

IMPROVE

Likelihood to

1 in

560

Outcomes to

0

1.0 10.0 89.0

%

Example

RATING

RATING SCORES AFTER IMPROVEMENT

Average:11

Score:

9413

The risk of a severe or serious outcome occurring is increased by the severity of the mould

growth in the bathroom and in the smallest of the three bedrooms, this being most likely to

be occupied by a child. The output of spores will be significantly above the level given by

the damp and occasional slight mould found in more average situations. The psychological

effect may be a further contributing factor causing harm.

0.15

76.3

38 >

Av: 89.0

76.3

38 >

0.15

Average likelihood, outcomes and HHSRS score for hazards from damp & mould by persons

aged under 15 years in 1946-79 non-HMO,1997-99.

0.15

%

0.0

38 >

2.2

38 >

21.5

0.3

0.7

1.5

3

7

15

26

Av: 1.0

2.2

0.3

0.7

1.5

3

7

15

26

Av: 10.0

21.5

0.3

0.7

1.5

3

7

15

26

0.3

0.7

1.5

3

7

15

26

0.15

< 0.05

< 0.05

< 0.05

< 0.05

Low

High

Average: 0.0

0.0

The presence of such severe mould growth in the bathroom and, to a lesser extent, in the

smallest of the three bedrooms, means that the risk of causing or exacerbating asthma and

other respiratory illnesses due to the inhalation of spores becomes extremely likely over a

12 month period. Such a severe outbreak is also likely to have a pschological effect on any

occupant.

Justification

OUTCOMES

Class I

Class II

Class III

Class IV

Justification

240 130

75

42

24

13

7.5

4

2.5

1.5 >

420

< 4200 2400 1300 750

Average: 446

Example

1

Low

High

1 in

1

LIKELIHOOD

HHSRS VERSION 2

SPETEMBER 2004

HEALTH AND SAFETY RATING SYSTEM SCORES

1946-79 purpose-built Flat