Why do you need to do this
On older caravans the window rubbers are prone to deterioration
and in order to prevent the risk of water ingress from
the window it is advisable to replace them. Our guide shows
How the window seals work
The basic construction starting from the outside is the
main window with its window locks and edging strip fitted,
this edging strip has a beaded edge along it which fits
into a groove in a strip which is then screwed onto the
caravan, seated with a suitable sealant.
Then we have the caravan side of it, starting with the
parts fitted to the caravan, we have the main rubber seal,
which is made to fit the caravans walls, each caravan is
different here, some have a thicker section than others,
and the rubber seal fits around this, with two lips. The
rubber seal is actually sealed onto the window aperture,
with a suitable mastic sealant, and then stapled into place.
On top of this there is a plastic strip that fits into
two small rubber lips in the top of the rubber seal, this
is a facing that covers all the staples but is necessary
also for appearance. On top of this, all the plastic fitting
for the window handles are screwed including the two window
Stage one - work out how you are going to do the
There are two ways of replacing the window seals
||1. re-do the seal only without removing the window
- and to do this, the window will need to be propped open,
to keep it up out of the way;
2. the other way, is to remove the window, and do the seal at the hinge
strip too, which will let you examine the condition of the sealant at the
hinge strip; if you took it off and found the sealant deficient, you'll
be glad you did.
|But lets look at the receiving end of the window
just now and we can deal with the removal of the actual window
and its hinge later.
Stage 2 - Removing the window and
The first job to do is to open the window. Then on the
inside of the caravan with a pencil and mark either end
of each of the plastic window fittings, so that they can
be put back in the right places.
Make a careful note of how this small hinge for the window
stay is fitted, which way up etc, take a screwdriver and
undo the two window props on the caravan so that they hang
Prop the window up out of the way, you can use a suitable
piece of wood but be careful not to open it too far, beyond
its limits, (some caravans have a window rail that runs
the full length of the caravan, in which case you can loosen
the small screw in the plastic clip in the window hinge
and slide it along, then slide the window along behind
Noting the way the fittings go, remove them and
keep them safe along with their screws. Go to the top end
of the seal and find the join in the top of the white plastic
now pull it out until the other end is seen, then mark
it. (Do not mark it on the rubber seal - mark it on the
interior of the caravan wall, just a small mark is necessary,
also put a small mark or take a note of what way up the
Pull out the trim all the way around, and keep it in a
safe place. You may be horrified at what you see when you
remove the trim; when I opened mine up I found that ALL
the staples at the lower part of the window had rusted
away, this may not necessarily be that the caravan has
rusted them all - remember that you caravan windows can
get steamed up at night or in wet weather, this is all
it takes, through time.
Stage 3 - check the sealant
Go around the lip of the seal that is in contact with
the body of the caravan, and pull it back a little if possible,
if no sealant sticks to your fingers then you need to replace
the sealant, using a screw driver, go around the staples
and lever them up a bit, you will find that some will break
and some will be non-existent, just lever up what you can.
Go around with a pair of pointed pliers and pull them out,
don't worry about the stubs that you can't get. Go to the
middle, bottom of the window seal and find the join, pull
one end up, and have a look at how it fits, and then carefully
peel it back all the way around, put it somewhere safe.
Get the ordinary pliers and go around the window opening
pulling out all the stubs of the staples that couldn't
be removed earlier.
| Check the timber and re-seal
How does the timber in the frame look? Is it dry and sound?
If so, good!
Go around the window opening with a chisel or a wide flat
bladed screwdriver and scrape away all of the sealant that
is left, it will probably look like putty but not sticky,
be careful when removing it from the outside metal panelling
of the caravan; just remove the most that you can, then
use petrol or white spirit to clean the rest.
Open the tube of Sikaflex and load it into the gun, and go around all
the holes in the wood filling them with the glue, if you find the metal
coming away from the wood in the frame, use a little Sikaflex to glue
it back too.
The rubber window seal now needs to be cleaned and examined,
just scrape off the excess sealant, then go around looking
at the general condition of the rubber, check for splits
and perished areas - Watch out for staples still stuck
in the rubber. Clean the white plastic strip too; the rust
from the staples can be cleaned out using a wire brush.
The tools you need
Replacing the window mastic is not easy, and it is time
consuming, there are a lot of things to remember and a
dry sheltered area is required, it is not the sort of job
you can just do out side on a whim, even if the weather
is excellent at the time.
The tools needed are as follows:
- A good selection of screwdrivers
- A good pair of pliers
- A good quality staple gun with 10 - 14mm staples
- A small hammer
- A selection of chisels (they don't have to be
- A pair of vice grips (you'll find out why, later)
- Some petrol and some good but, old cloths
- A sealant gun
- A small tub to put small parts into
- A bin
- A tube of IDL99 sealant
- A tube of Sikaflex adhesive/sealant
- A drill/driver and screwdriver bits
- A set of HSS drill bits
- A few pairs of rubber/latex gloves, and some
old clothes, and
- A Stanley scraper with its plastic blade.
|The advice and tips on
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