Channeling plaster for cables?

[Sam Gangee]

I have to install some coaxial cables for my aerial system. I thought the aerial guy would do it but he says he normally gets an electrician to dig the channels then a plasterer to cap the cables and fill them in afterwards! This seems a bit extreme (and expensive) to me.

I'm reasonable at DIY so I wondered if anyone could give me tips about chiselling the channels, holding the coaxial cable (without kinking or crushing it), capping it (with what?) and plastering over. The cable is standard black "fully-shielded coaxial" about 7mm in diameter.

For example how wide/deep do the channels need to be and what do I do if the plaster isn't deep enough? It seems shallow - about 15mm - in the place I've just tested. Is it OK/easy to chisel the brick?

Also appreciate any advice about digging out the holes for the wall sockets. Apparently they need to be deep enough for a 32mm steel box.

Edit: and I've never plastered before. Will "Polifilla" be OK?

 

[mo2]

do a search, youll find many wall chasing tips

http://tlc-direct.co.uk/Main_Index/Cable_Accessories_Index/Capping/index.html

galvanised capping ^^ chanel slightly wider than that



for filling over, again search, plaster might be better than polyfilla

Make sure you don't go through any live cables or pipes

 

[Adam_151]

I'd use one of the cables approved by the CAI, such as ct100, pf100 instead of something thta you don't know the quality of... have a look at what you have got and see if it says anything like that on it?

Would try and put cable in oval conduit if it would fit

Mark the chase and the box cut out on the wall remember for the box that its smaller than the face plate, channel by holding the chisel vertical turning it at a sliught angle and cutting through the lines to get rid of the plaster, you then have a shallow channel... brick is a pig to channel in but it can be done, breeze block is easy, just put the chisel in the back corners of the channel, and hit it a few times and then move it more torwards the middle and work on removing the section... rinse and repeat.

For the box... set the depth stop on your drill (or wrap insulating tape round the bit!) gang drill along the edges of the box outline, chisel out the bit in the middle, kind of use the chisel to 'shave' the top few mm off, rinse and repeat, etc

Sorry, not that good at explaining it, hope you get the idea

 

[comms]

Capping you could use:
http://www.tlc-direct.co.uk/Images/Products/size_3/MTCAP12.JPG

To fix coax to wall and not bother with capping:
http://www.tlc-direct.co.uk/Images/Products/size_3/TCR7SLASHBROWN.JPG

To chase the wall & sink back box use these:

http://www.toolstation.com/messages.html?closeUp=33171

To fill the chase over the cable use something like this:

http://www.tlc-direct.co.uk/Images/Products/size_3/FXPL5.JPG

 

[Sam Gangee]

Wow, thanks for the fast replies! I expected my question to languish unanswered for weeks. I'll check out those links and I'll re-read your posts when I'm feeling less tired.

Yes, the cable is H109F so it will be fine. (I'm told that CT100 is no longer manufactured so this is the nearest equivalent).

 

[RF Lighting]

You should not clip the cable directly to the wall and plaster over it.

Use some oval conduit (or 2nd best capping).

For the cost of a length of oval conduit (about £3) it will save a whole word of hastle if one of the cables goes down and requires replacing, or something superseeds it in the future.

 

[Sam Gangee]

Darn, I'm not going to be able to sleep while I'm thinking about this!

Assuming I use capping, how do I hold it and the cable in place while plastering? Ditto the oval conduit?

What depth of plaster is needed to cover the capping? I'm trying to work out the total depth of channel. I looks like 7mm (cable) plus 1mm (capping) plus plaster depth.

(I can sort of see the advantage of oval steel channel - you could pull new cable through - but getting the cable through in the first place looks like too much of a challenge!)

I'm beginning to see why the quote seemed high. Not quite as easy as it seems!

What's wrong with plastic capping?
.
I did search the forum but most of the discussions are about professional wall chasing like this: //www.diynot.com/forums/viewtopic.php?t=39432&highlight=wall+chasing
//www.diynot.com/forums/viewtopic.php?t=8086&highlight=wall+chasing

 

[streetlighter]

Use capping nails to hold the channel in place,nothing wrong with using pvc capping but some prefer the metal stuff. Id go further to say use 20mm pvc conduit held in place with crampets idea as you can draw new cabling into it as requirements change.
An SDS drill with a chisel bit makes channeling brickwork a lot easier.
J

 

[Sam Gangee]

OK, I've done a Google search for "crampet" and they are rare as hens' teeth! (Apart from that, Google thinks I'm looking for "crumpet"!)

I assume this picture is what you mean:
http://www.tlc-direct.co.uk/Products/CO20CRAMP.html

But how do you hammer it in? There's no way to get a direct blow of the hammer on the "head". Do you need a specially shaped drift?

SDS drill noted. I think I know someone who might lend me one.

Edit: jeez, one of the brick walls has plasterboard on it. I think you call it "dry lined"? How do I thread the coax cable behind it?