HHSRS VERSION 2
HHSRS VERSION 2
SEPTEMBER 2004
STRUCTURAL COLLAPSE
Vulnerable age
Related hazards
A) Foot of bath
Front elevation
All ages
Dampness, Personal Hygiene
Yes
Yes
No
No
Multiple locations
Secondary hazards
A) Head of bath
A) Floor below bath
DESCRIPTION OF HAZARDS
Dwelling:
1930s semi-detached house
A)
Floor below bath: The bathroom is on the first floor at the rear of the house above the kitchen. Wet
rot in the floor below the bath has caused the boards to rot and some of the end of the floor joists to
lose their bearing. The edge of the bath adjacent to the external wall has already dropped by up to 3
cm, resulting in cracks and bulging to the kitchen ceiling below. Immediately below the bath are the
kitchen units, which include an electric cooker.
LIST OF RELEVANT MATTERS
LIKELIHOOD
A
A
a
Structural movement
3
q
Defective internal walls
-
b
Structural cracks etc
1
r
Insecure internal frames
3
c
Open joints - to brick etc
-
s
Loose fittings & fixtures
3
d
Cladding defects
-
e
Loose coping(s)
-
OUTCOMES
f
Loose guarding
-
x
Height above ground
1
g
Structual damage
3
y
Size/weight of element
3
h
Disrepair to lintels/sills
-
i
Insecure frames or hinges
-
# Secondary hazard
j
Roof movement
-
None
-
k
Loose roof covering
-
l
Loose pots - to chimneys
-
m
Insecure rainwater goods
-
n
Staircase failure
-
o
Insecure guarding
-
p
Defective ceilings etc
3
Key
3
Seriously defective
1
Not satisfactory
Defective floors
3
2
Defective
-
Satisfactory/NA
Average likelihood, outcomes and HHSRS score for hazards from structural failure for all
persons in 1920-45 houses, 1997-99
Score
HHSRS VERSION 2
SEPTEMBER 2004
HEALTH AND SAFETY RATING SYSTEM SCORES
1920-45 House
LIKELIHOOD
Low
High
Average: 9,010
< 4200 2400 1300 750 420 240 130
75
42
1 in
18
Example
18
24
13
7.5
4
2.5
1.5 >
Justification
OUTCOMES
Class I
Class II
Class III
Class IV
Justification
RATING
The rot in the floor has been caused by penetrating damp through the walls where the
render has failed and is likely get progressively worse. While not immediately unsafe,
the weight of a full bath of water and person, particularly if heavy, is likely to lead
increasingly to a total collapse of the floor and bath. It is judged there there is a 1 in 18
probability of this occurring over the following 12 months.
%
Average: 0.2
2.2
< 0.05 0.15 0.3
0.7
1.5
3
7
15
26
38 >
Av: 0.0
10.0
< 0.05 0.15 0.3
0.7
1.5
3
7
15
26
38 >
Av: 9.6
31.6
< 0.05 0.15 0.3
0.7
1.5
3
7
15
26
38 >
Av: 90.2
56.2
2.2
10.0
31.6
56.2
1
< 0.05 0.15 0.3
0.7
1.5
3
7
15
26
38 >
Although the structural collapse is likely to be confined to the bathroom floor and bath,
the location of the kitchen, particularly the electric cooker immediately below the bath
increases the chance of a fatal, severe or serious outcome occurring, well above the
average.
Average: 1
I
J
Example
A B C D E F G H
2335
Score
RATING SCORES AFTER IMPROVEMENT
IMPROVE
Justification
NEW RATING
Av: Nos
Likelihood to
1 in 5,600
Outcomes to
0.2
0.0 10.0 89.8 %
Fully repairing the bathroom floor and external walls to prevent further penetrating damp
would, by solving the only structural problems in the dwelling, reduce the both likelihood
of structural collapse and the spread of harms to average.
Improved
A B C D E F G H
I
J