I need a 4" hole through brick, for an extractor fan. The ony problem
is that its two floors up, and there's no access to the outside wall.
It's directly above a small tile roof and the only place to put a
ladder is about 6' to one side and too small to put a scaff tower.

Really I need to think of a way to core drill and fit this, working
entirely from the inside and without dropping the plug.

Any bright ideas?

I can probably lay some plywood and carpet over the roof temporarily,
just in case of falling masonry, but I'd rather avoid dropping
anything big and heavy.


Thanks

On Mon, 18 Apr 2011 05:52:15 -0700, Andy Dingley wrote:

I need a 4" hole through brick, for an extractor fan. The ony problem is
that its two floors up, and there's no access to the outside wall. It's
directly above a small tile roof and the only place to put a ladder is
about 6' to one side and too small to put a scaff tower.

Really I need to think of a way to core drill and fit this, working
entirely from the inside and without dropping the plug.

Been there, done that.

Core drill from inside. The plug *should* stay in the core drill (fingers
crossed!).

Drop rope out through hole from inside.

Fit vent terminal to bit of 4" soil/vent pipe using stixall or similar
sealant/adhesive - don't let it set as you'll need to allow a bit of
wobble as outside wall and axis of hole bound not to be perfectly
perpendicular.

Apply one-part PU adhesive to wall-mating surface of vent terminal.

Thread rope through pipe & loop around stick on outside of vent terminal.

Pull rope up from inside, reaching out through hole to help pipe & vent
terminal in and to align terminal & bed it against wall, keeping tension
on rope (tie it to something) until glues have set.

Repeat steps above applying industrial-strength Anglo-Saxon as it all
falls apart leaving your hands coated with glue.

When adhesives have set release rope, attempt to remove any surplus glue
via whatever access you do have, job done!

--
John Stumbles

Hypnotising Hypnotists Can Be Tricky

"Andy Dingley" wrote in message
...
I need a 4" hole through brick, for an extractor fan. The ony problem
is that its two floors up, and there's no access to the outside wall.
It's directly above a small tile roof and the only place to put a
ladder is about 6' to one side and too small to put a scaff tower.

Really I need to think of a way to core drill and fit this, working
entirely from the inside and without dropping the plug.

Any bright ideas?

I can probably lay some plywood and carpet over the roof temporarily,
just in case of falling masonry, but I'd rather avoid dropping
anything big and heavy.

If you use a diamond core drill I wouldn't expect the plug to fall out,
especially if its still got the pilot drill in.
You would have to go easy on the last bit to avoid breaking the edges off.
I doubt if a TCT core drill would do as well as they tend to break the edges
if you try and breakthrough with them.

If you are any good at metal work you could always cantilever a ladder so
the top bit goes where you want it. Maybe even fasten one of those odd three
jointed "universal" ladders on top. Test it well before using it though.

On 18/04/2011 14:10, dennis@home wrote:


"Andy Dingley" wrote in message
...
I need a 4" hole through brick, for an extractor fan. The ony problem
is that its two floors up, and there's no access to the outside wall.
It's directly above a small tile roof and the only place to put a
ladder is about 6' to one side and too small to put a scaff tower.

Really I need to think of a way to core drill and fit this, working
entirely from the inside and without dropping the plug.

Any bright ideas?

I can probably lay some plywood and carpet over the roof temporarily,
just in case of falling masonry, but I'd rather avoid dropping
anything big and heavy.

If you use a diamond core drill I wouldn't expect the plug to fall out,
especially if its still got the pilot drill in.

That was certainly my experience of how it happened when I drilled for a
ventilator from inside my bathroom. I did have access to the oustide,
but didn't fancy standing at the top of a ladder holding an industrial
drill gun one handed and I didn't have any scaffolding.

You would have to go easy on the last bit to avoid breaking the edges off....

I found the anti-backflow shutter on the outside was large enough to
cover any spalling.

Colin Bignell

On 18/04/2011 14:09, John Stumbles wrote:
On Mon, 18 Apr 2011 05:52:15 -0700, Andy Dingley wrote:

I need a 4" hole through brick, for an extractor fan. The ony problem is
that its two floors up, and there's no access to the outside wall. It's
directly above a small tile roof and the only place to put a ladder is
about 6' to one side and too small to put a scaff tower.

Really I need to think of a way to core drill and fit this, working
entirely from the inside and without dropping the plug.

Been there, done that.

Core drill from inside. The plug *should* stay in the core drill (fingers
crossed!).

Drop rope out through hole from inside.

Fit vent terminal to bit of 4" soil/vent pipe using stixall or similar
sealant/adhesive - don't let it set as you'll need to allow a bit of
wobble as outside wall and axis of hole bound not to be perfectly
perpendicular.

Apply one-part PU adhesive to wall-mating surface of vent terminal.

Thread rope through pipe& loop around stick on outside of vent terminal.

Pull rope up from inside, reaching out through hole to help pipe& vent
terminal in and to align terminal& bed it against wall, keeping tension
on rope (tie it to something) until glues have set.

Repeat steps above applying industrial-strength Anglo-Saxon as it all
falls apart leaving your hands coated with glue.

When adhesives have set release rope, attempt to remove any surplus glue
via whatever access you do have, job done!

They are a little more expensive, but you can buy a vent kit that has an
extractor fan, outer cover with seal and the 4" tube, where the 4" tube
has grooves along the outer surface, designed to take screws from the
end. This means that you can screw the outer cover to the tube, use a
rope to pull it into place, squirt some low expansion foam around it and
then when it has set, simply screw the fan to the inner end of it.

I used one of these as my ladders were trapped in the garage by my
kit-car that had half the suspension disassembled!

SteveW