Running cable through a tiled roof

[HDRW]

I am a Radio Amateur and want to run an antenna cable through my house's tiled roof up by the chimney (length of cable run is important and running it down over the tiles, over the gutter then up and in through the soffit is too long - and there's no way to fix the cable on the 5m run down the tiles).

I have a device (gland?) designed for taking flues and pipes through a roof, but sized for the cable I have. It's an aluminium plate with a silicone "cone" which you cut to fit the cable, and screw/stick the plate to the tiles with sealant underneath for weatherproofing (and round the cable entry, obviously).

I'm OK with the general procedure, but unsure where to drill through the tiles. They're red Marley 165 x 265mm tiles, battened at 100mm (actually 4" as it was built in 1937!) and the roof has a 40 degree slope.

I'm thinking the gland should be lined up with the bottom edge of a tile, so it doesn't cross any gaps, with the top edge tucked under the tile pair above. If I drill for the cable through the middle of that tile it will go through the gap in the pair of tiles beneath, and I think will miss the battens.

I'm not sure wherther to use the self-drilling screws that came with the gland, or just rely on the silicone sealant to keep it in place - I'm worried about cracking the tiles with the screws, which would be a disaster!

Any comments/advice?

Cheers,
Howard

 

[catlad]

You would be best to remove the tile from the roof and the offer your cable flashing to the tile and mould it to suite the profile of your roof tile, then I would pencil a mark on the tile were I need for the cables to come through then I would use a grinder to cut a piece of tile out.

 

[HDRW]

OK, thanks for the advice.

Not sure what you mean about the grinder, though - I'll need about a one-inch circular hole in the middle of the tile, and I don't know how you could grind that?

Cheers,
Howard

 

[Jackrae]

Does your roof have sarking (wooden planks) under the tiles. If not then, have you considered simply thread the cable down between a pair of tiles.

 

[HDRW]

No sarking, the tiles were originally just hung from the battens, and the inside of the roof was the underside of the tiles (not even roofing felt!) but it's since been insulated with sprayed foam on the underside of the tiles - I'm going to chop it away in the relevant area, but the tiles don't lift easily even when this is done.

And the size and (lack of) flexibility of the cable doesn't make this feasible - it's not TV aerial cable, it's 10mm in diameter and won't bend to less than about 150mm radius. I really don't want the bottom of the tile held 10mm "open".

I'm also planning to run the cable in a flexible metal conduit, which puts the diameter up to about 25mm.

Cheers,

Howard

 

[catlad]

If you can't remove the tile then a grinder will be tricky, just drill a 4mm hole with a masonary bit then 6mm then 8mm 10mm and so on till you have the hole you need.

 

[Nige F]

NOT on hammer though - or hire a diamond core drill Tuck the top of ali flashing under tile and use silicone only to fix it

 

[dobriain]

Howard, How did you get on back in 2014. I have the same problem and I am interested in your solution in the end.

 

[catlad]

You can fashion your own out of a piece of lead to weather proof any hole you make, but there are a few products available now with the solar panel boom!