We've just moved into a house that was converted from a bungalow a few years
back; all the interior walls upstairs are plasterboard. I want to install a
DAB aerial on the roof and ideally run the cable through the loft and down
through the gap between the wall by our study. My draft action plan is:
Install aerial and run cable up to just above my study (need to find some
method of measuring distances to ensure I'm in the right place)
Drill a hole through to the cavity
Drop cable down into cavity
Drill hole through wall in study and attempt to locate cable
Install wall mounted coax point
It all sounds fine in writing but I wonder whether I'm setting an achievable
goal, so I'd welcome opinions from the experienced!
the studwork ensures you wont have
far to look - from above it's usually easy
to see where you are in relation to the
room beneath - drill through and drop a cord
with a weight on it, this can be tapped on the floor
if you really don't know where you are - you can then
work out where your studs are and drill the access
hole somewhere in between, using a straightened coat
hanger you can fish for the cord - much simpler than
I've never done this but how about dropping a plumb down there (it will hang
nicely unlike the wire) and then attach the wire to the end of the plumb and
pull it back up?? instead of trying to fine the wire
before you drill use a strong magnet on the end of a string dropped
down the cavity, then lift a few inches off the floor so it hangs
free. Tie it off to something large on the upper floor! - careful
exploration with a decent magnetic compass will pinpoint where it is.
Gives you the vertical line and if you want to be really finicky you
can pull it up the required amount to give you the horizontal position
Had excellent results using a strong magnet from an old disk drive
through single thickness of brick doing this.
Over the years I've gone from taking out a half brick to just removing
the vertical mortar between a couple of bricks, and just an inch or so
of that. Pity that the "regs" now don't approve using the cavity as a
big cable duct ....
(Please put out the cats to reply direct)
Achievable - certainly; fiddly - also certainly. The long "wot I did in
the last few days before getting back to work" screed I posted earlier
today - "Adventures in Loft Land" or some such title - describes recent
cable-fishing experience in gory detail. Those were all *internal* stud
walls, i.e. plasterboard both sides; I'm assuming you have the same (since
if it was an external wall you'd just come right through from outside,
In which case: when you go up in the loft you'll probably be able to
work out quite quickly from stable reference points - e.g. overflow
pipes, end walls, etc. - roughly where the internal wall is. I find it
a Good Idea to confirm the guess with a small hole drilled up through
the edge of the ceiling - your smallest masonry bit at 4mm is plenty,
or poke up with a bradawl - then feed a stiff bit of wire or similar
(hell, bamboo BBQ skewer will do, you won't be using them in this weather
;-) up through it and see just where it pokes up. You can fill this hole
with a dabette of Polyfilla or similar Later.
Now you know more certainly where the internal wall lies from the top.
This is a good moment to cut the hole for the back box of your coax point
where you want it; at "standard" wallbox size, about 7cm square, it's big
enough to poke in fingers, and a tape measure to get a good idea of the depth
of the cavity (tells you how far along from your trial hole to drill your
down-hole). Plasterboard is easy enough to saw with a full-size hacksaw blade
held in the gloved hand, or a sawblade you can get for Stanley knives, or
similar: you certainly don't "need" a Rotozip cutter (though if your heart
is set on one, far be it from me to stand between you and your tool-lust ;-)
If you have a mirror narrow enough, you can now look up the cavity, shining
a torch into it from a position close to your eye to carry the reflected
light where you're looking. If the gods of d-i-y want to trip you up on a
different part of the job, you'll find no noggins in the way. (If there
are, you'll have to cut out little bits of pboard above each one, drill
through at an angle, and then fill the hole, e.g. by gluing scrap bits of
pboard or similar to the back of the neat piece you cut out, using glue/filler
on the front side of those wings, and pulling it up against the inside
surface of the pboard with a screw you put in the main bit of pboard, or
a bit of string/wire looped through it; then fill the screwhole and edges
when the glue/filler has set).
Now hie thee back into the loft; drill that hole in the pboard above the
cavity, within a couple of inches horizontally-speaking of the exit hole
you cut below, to increase your chances of fishing out the dropped cable.
Drop in either the DAB downlead itself, or a handy-dandy bit of spare cable;
something relatively heavy and neither very stiff nor utterly floppy is
best. Attach a weight to the end if you like; I don't bother. It's useful
to mark the vertical distance down to the exit hole on this dropped cable:
then you know you've dropped enough (in practice drop at least a foot more,
to allow for some gentle bending on the way down).
Now comes the fun bit: finding it in the cavity near to the exit hole.
Working with an Assistant can help - one to drop, the other to watch and
listen as it bumps and rattles its way down. But if you're working on your
own, it's not too bad. You may be able to see the dropped cable near the
exit hole (a white jacket shows up better in the gloom!); or you may be
able to feel it if you're very lucky; or you may find an improvised hook
at the end of a bit of wire coat-hanger brings you the dropped cable -
worked for me on the very first attempt on one of this weekend's drops. Or
you can try the uk.d-i-y Tape Measure Trick, which has worked for me in
the past: feed a big loop of steel measuring tape, or the package-strapping
which comes round your Screwfix parcels (favoured access tool of the
car-nicking scrote), horizontally into the cavity, *before* you drop the
Expeditionary cable. The aim is to get it to form a loop around the edges
of the cavity. Now drop the cable, and pull the loop back out: with luck
it'll bring the dropped cable with it.
At this point, with the dropped cable pulled through, relax with a beer,
tea, or similar. Sod & Murphy will get you later anyway - e.g. making
sure you cut the DAB downlead 50cm too short anyway, or by having your
draw-wire part company from the DAB downlead even though you taped them
together good&proper, or by arranging a lightning strike to take out
aerial, downlead, and that nice new DAB tuner a week after you've put
it in. So take your pleasures when you may...
Hope this helps - Stefek
It ain't easy! Stud partititions typically have uprights at 18" centres or
thereabouts. But they also have horizontal studs - often at about one third
and two thirds of the room height. So if you want to go from above ceiling
level down to nearly floor level, you'll have to drill through not only the
top member but also the two intermediate members - and I bet you don't have
a long enough drill!
If you don't mind bringing the cable out near the ceiling rather than near
the floor, or if you don't mind removing and making good a small piece of
plasterboard in the region of each horizontal stud sufficient to get a drill
in from the side, you might manage it.
There are 2 caveats here ... either of which could P** on your chips.
First if three is any insulation in the studding, this will prevent the
cable dropping ... I have always fully filled stud walls with insulation
... as it cuts down noise (now Blding regs requirement)
Secondly it is very unlikely that you will have uninterrupted space form the
sole plate to the header ... i.e. between the top and bottom of the wall
.... it is common practise ( and needed on plasterboard) to have
intermediate horizontal noggins .... this would mean your cable would stop
half way down where it meets the noggin.
Sorry if this is doom & gloom after the other positive posts ... but thought
I would mention what could happen.
If its a wooden framed stud wall there are bound to be horizontal noggins
which will stop your cable or weighted string going very far.
I cut short vertical slots in the plasterboard across these noggins and also
into the noggins to take the cable. Then you have to make good afterwards...
I'd probably use the same approach, although it can start getting messy,
have a look for another route - there is usually an sv pipe going through
into loft space (unless outside) have a look there, or possibbly where CW
pipes go to tank if you have a non-pressurised system.
Yup, a definite possibity for external dry-lined walls; is it common
(or indeed now required) on internal stud walls too?
Aah, thanks for the Naming Of Parts: "sole plate" being the horizontal
timber at the bottom which the studs rest on, and "header" being the bit
wot the tops of the studs attach to, right? Nogginses is indeed a strong
possibility - mentioned in a couple of the posts - but not a certainty,
in my very limited but non-zero experience.
Not doom and gloom at all, just realism. "It's not the despair. The despair
I can deal with. It's the hope..." ;-)
Depending on your adherence to regulations, you can find where the
noggins are, make a hole above and below, and chip away the plasterboard
in between, and lay vcables over the top, and kmake good with plaster
Or if you are a purist, notch the noggin.
One thing about plasterboard, its dead easy to fit bits onto holes, skim
and sand flat and repaint. Compared with chasing a slot down an internal
brick wall...its easy peasy.
If you do manage to get the cable into the stud wall there is a neat
trick for getting it out through a small hole. Get one of those
plastic covered wire thingys used to hold up net curtains and strip
off the plastic. Stretch the wire out so it forms a spiral and stuff
it into the hole. Spin it round by rolling the bit sticking out in
your palms and with any luck the cable will become twisted up in the
spiral and you can pull it out through the hole.
Saw a BT engineer do this about 20 years ago but have never had to use
The snag is there'll be noggins - horizontal wood - between the studs,
probably two, and maybe three. These are to add rigidity to the wall and
prevent the studs warping which would show by pulling the clouts out of
*Why is the time of day with the slowest traffic called rush hour?
Dave Plowman email@example.com London SW 12
Thanks Dave, you really have found the first upside to a house built by a
current-day "what-we-can-get-away-with" builder: they only put one noggin in
per section when the built the internal walls upstairs!!!
So, only one big plasterboard square badly cut out and covered for me
Now, where is that drum of CAT5e and my best swiss army knife saw blade...
plasterboard here we come ;-)
In uk.d-i-y, Paul <paul at javajedi dot com> wrote:
BUTCHER!! EEEVIL MAN!!! :-) I was going to add "or the saw blade on your
Swiss Army knife" to the list of plausible pb-sawing tools, but it seemed
like sacrilege; especially as I have in younger years used these for sawing
through fresh wood and found them suprisingly effective, so the idea of
blunting one to hell for a few linear inches of cut in plasterboard was
below my own level of tool-torture acceptability.
Still, if you hate your SwissArmy knife that much... As for where the drum
(or rather Non-Tangle [tee-em] box) of Cat5e's gone: it's still in the den
waiting for me to be arsed to take it back to the loft. And our resident
network geezer hasn't found his way back to work yet in the New Year (or
may be in the US for all I know), so still no Pentascanner loan for me :-(
From the experiences gathered thus far, it seems that nogginses - nassty,
sssneaky little nogginsses, what'sss it got between itss studsess, eh,
Preciousss? - seem to be common, but not universal; hence opining that
they were just one of the ways for Sod and Murphy to make their presence
felt on this job, but that a less expected bugger-factor might be their
preferred method of pain infliction instead...
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