ANTITERMITE
TREATMENT:
GENERAL
Pre constructional anti-termite treatment is a process in which soil treatment is applied to a building in early
stages of its construction. The purpose of anti-termite treatment is to provide the building with a chemical barrier against the sub-terrain termites.
Anti-termite treatment being a specialized job, calls for thorough knowledge of
the chemicals, soils, termite to
be dealt with and the environmental conditions, in order to
give effective treatment and lasting
protection to the
property undergoing treatment. It is therefore imperative that the works of anti-termite treatment should be got
executed through specialized agencies only. The specialized agency should be preferably a member of the Indian pest control Association and shall have sufficient experience of carrying out similar works
of
magnitude envisaged in
this tender.
The
pre constructional soil treatment is
required to
be applied during the
construction
stages of the sub-structure up
to plinth level.
The contractor has
to be
watchful of the various stages of sub-structure works
and arrange
to carry out the soil treatment in time after
proper
co-
ordination with Department and other
contractors
if
any, working
at site.
SCOPE
The scope of pre
constructional anti-termite treatment covers the
soil
treatment with
approved
chemicals
in water emulsion in foundation trenches
for
columns, plinth
beams, plinth filling, at junction of walls and floor, in expansion joints
etc. in stages as detailed
in this
specifications and
drawings. Unless otherwise stipulated, the anti-
termite treatment
will be carried out as per IS 6313 (part II) 1981 and / or as per direction of the Engineer-in- charge.
SITE PREPARATION
In
order to
ensure uniform distribution of the
chemical
emulsion
and
to assist penetration, the following
site
preparation shall be carried out:
a)
Remove all trees,
stumps,
logs or roots from the building site.
b) Remove all concrete form work if left anywhere, leveling pegs, timber off-cuts and other building debris from the area to be treated.
c)
If the soil to be treated is sandy or porous, preliminary
moistening will be required to fill capillary spaces
in soil
in order
to prevent the loss of emulsion through
piping or excessive percolations.
d) In the event of water logging of foundation, the
water shall be pumped out before application of
chemical
emulsion and it
should be applied only when the
soil is absorbent.
e) On clays and other heavy soils
where penetration is likely to be slow and
on sloping sites, where run-off of the treating solution is likely to occur, the surface of the soil should be scarified to a depth
of
75mm at least.
f)
All sub-floor leveling and grading should be completed. All cutting trenches and excavations should be completed with
backfilling in place, borrowed fill
must
be free from organic debris and shall be
well compacted. If this is not done supplementary treatments should be made to complete the barrier.
Chemical to
be used:
The effectiveness
of chemical
depends
upon
the
choice of
the chemical,
the dosage adopted and
the thoroughness of application. The chemical solutions or emulsions are required to be dispersed uniformly in the
soil and to the required strength so as to form an effective chemical barrier which is lethal and repellent to
termites.
Soil treatment:
One of the following chemicals in water emulsion, after approval from the Engineer-in- charge shall be used uniformly over the area to be treated.
Chemical
|
% of
concentration of
Chemical by weight in
|
I. Heptachlor 20 EC emulsifable concentrates
(I.S.6439 – 19781-R)
|
0
.
|
II. Chlordance 20
EC emulsifable concentrates
(I.S.2682-1984 II-R)
|
1
.
|
III. THIODAN 35 EC emulsifable concentrates
(Endosulphan)
|
0
.
|
IV. Chlorpyriphos 20 EC emulsifiable concentrates
(I.S. 8944-1974)
|
1
.
|
The
contractor should
produce
voucher(s)
for
the chemical
purchased and should get verified the
sealed
container(s) of the specified chemical from the Engineer-in-charge before preparing the emulsion / use
for t he treatment.
Mode and Rate of Application:
The chemical
emulsion as
stated
above
will be applied
uniformly by
sprayers
at the prescribed rates as detailed below in all the sages of the treatment.
Treatment in Foundation Trenches:
In case of
normal
wall load bearing structures, columns pits,
wall trenches and basement, the
treatment shall be at 5 litres/sqm. or surface area of the bottom and sides to a height of at least 300mm. After
the foundation work, the sides shall be treated at 7.5
litres/sqm. of vertical surface of substructure on each side.
After the earth filling is done, treatment shall be done by rodding the earth at 150mm centers close to wall
surface and
spraying the chemical with the above dose i.e. 7.5 litres/sqm. In case of framed structure, the
treatment shall start at a depth of 500mm below ground level. From this depth the backfill around the columns,
beams and R.C.C. basement walls shall be treated at 7.5 litres / sqm. of the vertical and at 5 litres / sqm. for
the horizontal surface at the bottom in the trenches / pits.
Treatment on Top Surfaces on Plinth Filling:
The
top surface of the filled earth within plinth walls shall be treated with chemical emulsion at the rate of 5 litres/sqm. of the surface area before sub-base to floor is laid. If filled earth has been well rammed and the surface does not allow the emulsion to seep through, holes up to 50 to 75mm deep at 150 mm centers both
ways shall be made with crow bars on the surface to facilitate saturation of the soil with the emulsion.
Treatment at Junction of Walls and
floors:
Special care shall be taken to establish continuity of the vertical chemical barrier on the inner wall
surfaces
from the finished ground level (or from level where
the treatment had stopped) up to the level of the filled earth surface. To achieve this a small channel 30 X 30 mm. shall be made at all the junctions of wall / column
with floor (before laying sub-grade) and rod holes
made
in the channel
up to the
finished ground level
at
150mm apart
and the iron rod moved backward and forward
to break the
earth
and
chemical
emulsion poured along the channel at 7.5 litres (or at recommended quantity per sqm. of the vertical wall / column surfaces so as to soak the soil right up to the bottom. The soil shall be tamped back into place after this operation.
Treatment for Expansion
Joints:
The soil beneath the expansion joins shall receive special attention when the treatment under
2.5.1
above is in progress. This treatment shall be supplemented by treating through the expansion joint
after
sub- grade
has been laid at the rate
of 2 litres per
metre length of expansion joint.
Precautions during Treatment:
1.
Utmost care shall be taken to see that the chemical barrier is complete and continuous. Each
part of the area shall receive the prescribed dosage of chemical emulsion.
2.
The treatment should
not be carried out when it is raining or when the soil is wet with
rain or sub- soil water.
3. Once formed, the treated
soil barrier
shall not
be disturbed.
If by
chance, treated soil barriers are
disturbed, immediate steps
shall
be taken
to restore
the continuity and completeness of the barrier system.
Precautions for Health Hazards and Safety Measures:
All the
chemicals
mentioned above are poisonous
and hazardous to
health. These chemicals can have an adverse effect upon health when absorbed through the skin, inhaled as vapours
or spray mist or
swallowed.
Persons
handling or using these
chemicals
should be warned of these dangers and advised that absorption
through the skin is the most likely source of accidental poisoning. They should be cautioned to observe carefully all the safety precautions particularly when handling these chemicals in
the from of concentrates.
These chemicals are usually brought to the site in the form of emulsifable concentrates.
The
containers should be clearly labeled and should be
stored carefully out of the reach of children and pets animal. They should
be kept securely locked.
Particular
care
should be taken
to prevent
skin contact with
concentrates.
Prolonged exposure to dilute
emulsions should also be avoided. Workers should wear clean clothing and should wash thoroughly with soap and water especially before eating. In the event of severe contamination, clothing should be removed at once and the skin washed with soap and water. If chemicals splash into the eyes they shall be flushed with plenty of
water and immediate medical attention should be sought.
The
concentrates
are
oil solutions and present a fire
hazard owing to
the use
of petroleum solvents.
Flames should not be allowed
during mixing.
Care should
be
taken
in the application of
chemicals
/
soil
toxicants
to see that they are not allowed to contaminate wells or springs and other sources of drinking water.
Guarantee :
The contractor has to furnish the guarantee for
10 (ten) years from
the date of completion of work,
starting that in
case
of
reappearance
of
termites within the
building area due to
defective
materials or
workmanship
or due to any other reasons, the contractor will carry out the necessary post constructional treatment
to
keep the entire area free from termite, once again, without any extra cost to the Department during the
guarantee period.
Mode of measurement:
The payment will be made on the basis of plinth area measurements at ground floor only for all the stages
of treatment in sqm. correct to two places of decimals. Rate includes
the
cost of materials, labour and all tools,
plants, sprayers required for complete operation.