sealing a cable that passes through brick wall

[mic]

I have to get 0.25" cable through a cavity brick wall. I can drill the hole ok and get the cable though - but how to make a tidy job of it as regards sealing the ends? I could just squirt silicone into either side - but it wouldn't look that "neat". Is there a proper/better way to seal such things?

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember mic saying something like:

Angle the hole upwards from the outside so the sealant has less work to do. Loop the cable down and up before it enters the hole and use a dark mastic to seal the hole. Nobody will notice it at all.

[Lobster]

You aren't supposed to have exposed cables within cavity walls anyway - even just traversing the cavity. Probably because if you ever install polystyrene insulation in there it can attack the cables?

Neat way is to drill a large-ish hole (14mm? I forget) right through both inner and outer walls (angled upwards from the outside to stop water ingress) and to hammer through a length of plastic conduit (I used

0.5" polythene overflow pipe) making a tight fit to the brick at either end. Then seal the cable to the pipe at the outer faces as you've described. To get a good neat seal at the outside wall, extend the cable out of the wall for an inch, cover that liberally in silicone, then withdraw it into position - then you are sure to have plenty of silicone up the pipe.

There are grommit/covers available to cover the entry/exit points - cable TV installers use then - but don't know where you'd obtain them.

David

[Guy King]

The message from mic contains these words:

Telewest installers use a grommet where it's visible - basically they apply mastic but then shove a split grommet into the gunge just to tidy it up a bit.

Of course, if it's only a 1-off it needn't be a proper grommet - you may find something in the kitchen or bathroom like a small bottle cap you can cut down and adapt.

[The Natural Philosopher]

I would use foam to seal, mortar to prettify external wall and decorators caulk to do likewise inside.

[john2]

I ground up old old soft red brick (using a 1" masonary drill bit) and mixed the dust with white silicone filler. It looks the same colour as the rest of the wall now.

john2