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First of all as we have already mentioned - building a pond
using a liner is probably the easiest and simplest way to build
a pond - and of course the cheapest is to did a hole in the
ground, lay in a liner and then fill it with water .. but is it
really that simple .. in short yes if that's the sort of pond
that you want and that will suit you .. but installing a liner
into a 'hole' can be far more complex than that in real life ...
The Koi keeper on problem when electing to use a liner is how
to get a nice clean finish to the top edge .. not an easy task
at the best of times .. but one way is to build what is known as
a 'Concreter Collar' round the whole edge of the pond and this
will, or should if you do the job right, give you a clean and
tidy edge which will also support the liner a it is laid over
the top of the collar.
Having decided to have a collar then the first job you will
have to do is to mark out the shape of your pond taking care and
then to drive stakes into the ground at regular intervals using
small wooden stakes or pegs... When you are happy with the shape
then the next job is to dig out a trench which should be about
12" wide and about 9" or 10" deep to give the
concrete that you will pour into this trench some strength and
body ... Note that is the 'inside edge of this collar that
will form the actual size of your pond so make sure that you do
allow for this when you mark it out otherwise you could end up
with a pond smaller that you wished to have ..ok...
As the sides of the trench you have dug will be rough and the
edges may not be as straight as you planned then to overcome
these problems you can if you wish use 'Shuttering' using
suitable lengths of timber .. chipboard is cheap enough and
strong enough to hold the concrete firm whilst it sets ... so
spend a little time getting the shuttering right if you wish to
do a good job and one that you will be pleased with .. I
recommend that you do shutter both sides of the trench to
provide you with a nice neat and clean edge to your collar ...
but please make sure that your shuttering is level otherwise you
will not be able to use the actual shuttering as your top of
collar guide ...
When mixing the concrete you should use the standard mix of 3
parts gravel - 2 parts of course builders sand and 1 part of
cement ... Do not mix it too wet but it does have to be wet
enough for you to be able to tamp it down firmly making sure
that you get all the air bubbles, if there are any, out and then
you can use a suitable length of timber to finish it off leaving
you with a nice smooth top face . as this is what you will be
laying your liner on to .. so it does not want to have any sharp
stones or other object proud of the cement .. It is worth
spending a little extra time and effort to ensure that this
cannot happen ... Once you have got to this stage there may be a
tendency to rush on to the next job .. please don't be tempted
into rushing .. leave the cement collar to set for at least 2
days before you attempt to remove the shuttering ... as before
that period the concrete would not be hard and there is a
likelihood that you would damage the edges of the collar if you
removed it any earlier ...
Once you have removed the shuttering the next job I would
suggest will be to 'round off' the inside edge of the collar so
that the liner when it is placed into position will fit smoothly
over the edge without fear of damage to the liner .. You can
quite easily achieve a nice rounded edge by gently shaping the
corner with an angle grinder if you have one .. otherwise you
will have to do it slowly, so as not to chip or dig in too much,
with a cold chisel or similar tool ... When you have got to this
stage then my advice is to leave the concrete again to harden
off more for another couple of days .. as any work that you do
could cause damage to the collar and after all the work that is
not what you would wish to happen .. so take a rest and think
your plan out again making sure that you are working to plan and
that you do not wish to change your plan slightly as now is the
time to make any adjustment to your overall scheme ...
OK so we have left the concrete to harden off for another
couple of days so if you are sure that the work that has to be
done next will not cause too much damage to the collar - then
the next job is to start digging out your pond .. clearly this
is going to be extremely hard and heavy work .. and you will
find the help of a couple of friends (if they have not all
disappeared suddenly when they learnt what you were doing)
invaluable to assist you in this work - spade work can be very
tiring .. (so make sure that the spade you have bought is not
too large or too heavy for your wife to handle) only joking ..
but I am sure that your wife will at some time wish to be
helping in some way or anther and this is good if you can
encourage it .. this will provide additional interest once
the pond is done and you may find that your wife will derive as
much pleasure from the pond as you yourself ..
Of course you can, providing you can get one into your site,
hire a small 'Mini Excavator' which will make the job so much
easier and take all the hard back breaking work out of the
actual excavations .. you can hire one of these usually from
your local plant hire companies - or tool hire companies ...
They are available with a foot-print of not much more that just
3 feet - so they will pass through even the narrowest of places
if you are lucky and if all that is preventing you from gaining
access to the site with on of these wonderful labor saving
devices is a door frame then it is a relatively simple matter to
remove that door frame and re-instate this once the work has
been completed and would be well worth the effort or small cost
involved ..
If you are going to use a mechanical excavator - then please
be careful not to damage your collar .. learn how to control the
bucket and lifting arms before you cross that collar .... once
mastered you will be surprised how quickly the excavations will
be completed .. a smallish pond can be easily excavated during a
weekend when the Hire charges may be a lot less than during the
working week ... When all the heavy work has been done as far as
you can using the excavator ... then there will still be some
fine work to be done using the conventional spade with a little
bit of back-breaking work .. but these finishing touches are
very important ... so please don't rush the work ..
Bottom Drains....
I cannot emphasize enough the importance of the Bottom Drain
... so even if you are going to use a liner then give a lot of
thought into the fitting of at least one bottom drain rather
than just lowering a submersible pump into the pond .. yes
that is the traditional method and the one most widely used and
promoted by Garden Centre and other pond supply outlets that
simply do not have the knowledge to understand what the bottom
drain is ... and if they do know themselves then they are not
very quick to come forward and advise their own customers on the
use of them .. and as far as I am concerned 'They should'
because if they don't then they are not worth their salt or
worth dealing with ... If you have got this far and you still do
not understand what the bottom drain is for then please 'stop
right now' and go to our page which discusses the bottom drain
and learn about what it can do and how important they
really are ...OK
So I am now going to assume that you understand the bottom
drain and after reading all about them that you have decided,
very wisely, to use one in your own pond installation ...
That being the case then the next job is to begin to shape the
bottom of the pond - so that the base slopes from the sides down
to the middle (again see some of the drawings that we have done
showing this) .. I would suggest that the minimum fall from
edges to the bottom drain should be no less than 6" . this
will give enough fall towards the bottom drain making sure that
all dirt and debris are pulled towards the bottom drain ... Once
you have achieved this then the bottom drain should be set
temporarily in place so that the rim of the drain will be
level with the bottom of the pond. Then you have the job of
running the 100mm or 4" pipework from the outlet on the
bottom drain to where you are going to site your filter system,
when you are absolutely sure that you have it in the right
position, and remember that the actual pipework will rise up
'outside' the pond itself and beyond the liner .. then you can
carefully joint all the pipes together in the trench you have
previously dug allowing for you to set the pipework in a
concrete mix and also making sure that you place plenty of
concrete all round the bottom drain, especially underneath to
that they can be no possibility that the bottom drain will
move... One last point here please make sure that once you have
the concrete all round the bottom drain that the top is level in
both directions this is very important as you will see later
when you come to fit the liner itself...
Leave that new concrete round your bottom drain and pipes to
harden for at least 2 days.. and during that time you can make
sure that there are no sharp objects sticking out of either
walls or the bottom of the pond that could damage your liner ...
It is worth mentioning here that you can purchase a correct
under felt which fits underneath the liner .. it is well worth
the additional cost . but if these costs are prohibitive then
you can use pieces of old carpet that you have no further use
for ...
Either way, once you are satisfied that the concrete is hard
and neither the bottom drain or the pipework can move then you
can start to lay the underlay if you decided to lay one ... take
your time on this work it will pay you in the long-term... so
don't rush it ... remember any lumps you leave in the underlay
will also show under the liner ... and we don't really
want that to happen after all the work that has gone into it so
far ...
Fitting the Liner:
Firstly let me make it clear that it is possible to obtain
what is known as a 'Box Welded Liner' that means that if you are
creating either a square or a rectangular formal pond that it is
possible to have a liner specially made for your pond which will
have welded corners and therefore have no unsightly folds or
creases . but you do have to make absolutely sure that you give
the manufacturers the exact measurements and you must make sure
that the hole you dig is exactly to those measurements .. We can
supply Box Welded Liners to order and these normally take
between 4 and 6 weeks to be delivered to your site ...
If however you are fitting the standard liner then the
following points may be helpful to you .
Normally the liner will be supplied as a single sheet and
this will, I assure you, be extremely heavy so do not try to
move this by yourself unless you are the son of Hercules - get
someone to give you hand and the more hands that you have to
help you then the better ... so be nice for a week or two
towards your next door neighbour and your friends and relations
... When you have the liner near the pond then the best plan is
to lay it out if you have sufficient room and then with friends
take hold of the leading edge and gently drag the liner over the
pond excavation making sure that you have equal distance round
the concrete collar if you have used one ... Once in place
you can begin to lower the center section down into the pond so
that it lays over the top of the bottom drain and you have
enough room round it to be able to work on the actual bottom
drain securing it to the flange of the bottom drain ....
So now lets move on to fitting the liner to the bottom drain
.... keeping the liner as tight as possible will allow you to
feel the edge of the flange on the bottom drain through the
liner and you may be able to identify the screw holes that are
located in the flange enough for you to be able to carefully
using a 'bradawl' or similar shape pointed tool through the
liner locating on of the holes into which you can insert just as
a holding point one of the stainless steel screws but do not
screw this in too far .... once you have done one then moving to
the opposite side of the flange do the same at that side - this
will then secure the liner firmly in place whilst you very
carefully cut the centre of the liner out to the shape of the
bottom drain flange using the inside edge of course....
Once you are happy that the liner is in the correct position
and the pilot holes in the liner are lined up correctly with the
holes then the next job is to use a good quality 'Silicone' -
mastic - or what we recommend for such 'Paraflex' (available
from us) and lifting the liner upwards, getting one of your
friends to hold it up, you can then a apply a generous covering
of the 'Paraflex' or other sealant all round the lower flange
making sure that you cover it all .. don't worry about any
excess sealant that can be cleaned off later ... when you are
satisfied that you have covered the flange with the sealant then
slowly lower the liner down so that you can then move it into
place trying to locate the same holes that you made in the liner
.. and again as a temporary measure fit the two screws back in
to secure the liner again whilst you prepare to do the next
thing which is apply the sealant to the top section of the
bottom drain flange (the loose section) and once this has been
done push a screw through one of the holes ready to push the
point of the screw into one of the holes in the liner after you
have removed the screw that is holding the liner temporarily ...
having located that hole you can then do the same to locate and
secure the other side and tighten them down half way .. proceed
then to screw the other stainless steel screws through the liner
through the remaining holes .. once these are all in place you
can then firmly tighten down all the screws and clean off any
excess sealant that will have squeezed out and can be cleaned
off ... and work on that can stop for the day ...OK...
After leaving the sealant to cure overnight (at least) you
can then very carefully begin to straighten the liner out and
then you can begin to fill the pond with water - but make sure
the upright pipe coming from the bottom drain and which is
outside the pond is well above the proposed water level at this
stage ... as you fill the pond the weight of the water
will stretch the liner into the shape you have dug.. fill it
slowly and this will enable you to pull out many of the folds
and creased that are unfortunately unavoidable when using a
liner - if you can remain in the pond and with one of your
friends at the top you can possibly fold the corners as the pond
fills ... Once the pond is full you can then carefully
pull out the folds at the top edges of the pond and stretch the
liner over the collar and secure it in place until you finally
do the work that you have planned round the top of the pond ....
We can supply Double Sided Liner Tape for use with any PVC or
Rubber Based Liner -
Click on a shape below that best suits your pond to use our
handy Liner Size Calculators. |
