HHSRS VERSION 2

SEPTEMBER 2004

STRUCTURAL COLLAPSE

Vulnerable age

Related hazards

All ages

Damp and mould

HHSRS VERSION 2

Multiple locations

Yes

No

Secondary hazards

Yes

No

A) Slipped and missing slates on rear roof

DESCRIPTION OF HAZARD/S

B) Dormer to top floor rear room

Dwelling : Top dwellings in pre 1920 HMO

Background: The house comprises two floors plus a basement and attic and is generally in poor

repair. The rear roof, particularly, is affected by 'nail sickness' with many slipped and some missing

slates. The rear eavesgutter is loose. Chimney pots also appear unstable. Immediately below the

affected roof is a roof terrace for the top floor maisonette being assessed, and one floor below a wide

landing to common external stairs leading to the basement level garden. The hazard affects more

than one dwelling, but to different degrees.

LIST OF RELEVANT MATTERS

LIKELIHOOD

A

A

a

Structural movement

-

q

Defective floors

-

b

Structural cracks etc

-

r

Defective internal walls

-

c

Open joints - to brick etc

-

s

Insecure internal frames

-

d

Cladding defects

-

t

Loose fittings & fixtures

-

e

Loose coping(s)

-

f

Loose guarding

-

OUTCOMES

g

Structual damage

-

a

Height above ground

2

h

Disrepair to lintels/sills

-

b

Size/weight of element

3

i

Insecure frames or hinges

-

j

Roof movement

-

# Secondary hazards

k

Loose roof covering

3

None

-

l

Loose pots - to chimneys

3

m

Insecure rainwater goods

2

n

Staircase failure

-

o

Insecure guarding

-

Key

3

Seriously defective

1 Not satisfactory

p

Defective ceilings etc

-

2

Defective

- Satisfactory/NA

Likelihood to

1 in 5,600

Outcomes to

1.00 0.0 10.0 89.0 %

To reduce this hazard to average, the minimum works would include stripping, felting and

re-slating the whole of roof; renewing the rainwater goods; and replacing or removing the

chimney pots. However, other works are clearly required to the house as a whole. For

the top floor flat, the damp and mould growth - also resulting from the disrepair of this

roof - represents the most serious hazard, as shown by the previous worked example

(WE 01.2 V2).

Improved

IMPROVE

Justification

NEW RATING

Av: Nos

A B C D E F G H

I

J

Average likelihood, outcomes and HHSRS score for hazards from structural failure for all

persons in pre 1920 flats, 1997-99

Score

2

HHSRS VERSION 2

SEPTEMBER 2004

HEALTH AND SAFETY RATING SYSTEM SCORES

Pre 1920 Non s/c Flat

1 in

56

LIKELIHOOD

Low

High

Average: 24,098

Example

56

< 4200 2400 1300 750 420 240 130

75

42

24

13

7.5

4

2.5

1.5 >

Justification

OUTCOMES

Class I

Class II

Class III

Class IV

Justification

RATING

The likelihood of a person being struck by a falling element is significantly higher than

average. This is due to the location of the roof terrace above the back addition, this being

the only outdoor space available to the top floor maisonette, and the presence of the

common outdoor landing and stairs providing the main access to the basement level

garden. The fear of being struck, limiting the enjoyment of these outdoor spaces, is also

a factor increasing the likelihood of health outcomes such as stress as well as of physical

injury.

%

Average: 0.7

1.0

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 0.0

0.0

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 8.6

10.0

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 90.7

89.0

1.0

0.0

10.0

89.0

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

The health outcomes are judged to be no higher than average. However, with the high

likelihood of 1 in 56, this spread of outcomes gives a score of 248 and a band E rating.

Average: <1

I

J

Example

A B C D E F G H

248

Score

RATING SCORES AFTER IMPROVEMENT