On Mar 2, 12:09*pm, "John Grabowski" wrote:
wrote in message

...



OK I have a tricky situation.

I have to install quite a few recessed lights.

Most of them I have accessed (ceiling down), some of them I do not.
Of the ones I do not, some of them I need to drill large holes to
mount them, and some of them have existing non-functioning recessed
lights already in place I need to remove first.

I intend to use as much as I can get away with IC housings for new
work (not remodel) which means I need to get adequate access to the
space above.

The ones I already have 35 year old beat up non-functioning rusted
housing up there, with the flanges attached to the joists, and I need
to attach a new one (different diameter) I will have to figure out a
way to remove them, and attach new ones. *To make the matter more
complicated, the ceiling is not regular sheetrock, but a 3/4" thick
material which is composed of 3/8" of plaster on top of 3/8" of gypsum
board backing so cutting must involve a carbide blade.

I do have access to one of these:

http://www.holepro.com/powerseries.html#X-det

and can cut a large hole up to 9" in diameter. *I think my best bet
may be (I already disconnected the wirings) use a hammer to knock the
existing can back into the attic, then insert a piece of 1x2 wood into
the hole, and secure the wood to the drywall across the middle from
the inside using a few screws, then use this shielded hole cutter with
the starter screw going into the piece of wood in the center and cut a
9" big hole. *I tested this with a piece of scrap wall I demolished,
and it cut through it like butter and no dust.

That would allow me enough room to cut out the existing housing and
flanges, and probably enough room (I hope) to mount a new housing to
the joists. *The advantage is I can easily cut an identical piece of
9" hole and the patch would be perfect, and if I do that for all the
holes I do not have access (about 16 of them), the patching work would
be the same and no need to waste time measuring each hole being cut
slightly different sizes etc...

One other upside is that this hole cutter has a plastic see-thru
shield that collects the dust. *Using a rotozip angled up even wearing
eyegear there is no way to stop the nasty plaster dust from getting
into your eyes and nose.

The downside is I would be patching a round hole, which I have not
done before, how would you apply straight drywall tape to a round
hole? *Do you use short strips?

The other downside is in the event a 9" hole is not enough for me to
mount the new housing, I would have to further enlarge the hole until
I can...there is no going back to using remodel housing since the
drywall support from a patch would be inadequate.

Any thoughts or comments or alternatives?

*If you are able to get into the space above to install new recessed light
housings then why don't you just remove the old ones at the same time. *They
are probably just nailed to the joists.

To remove from below you should remove the trim and bulb. *Then loosen the
interior screws or clips holding the can in place. *Some are just held up
with friction and can be pulled with a good tug. *Cut out the can and you
are left with the frame in place. *You should be able to reach up through
the hole with a hammer or pry bar and pull the frame brackets away from the
joists. *I doubt that you will be able to pull the frame down through the
existing hole.

I have never used that particular tool for cutting holes. *I used a cheaper
version from Greenlee once and tossed it. *I have also used the specific
hole saws for each diameter recessed light with good results however they
can create a lot of dust. *Most of the time I just use a carbide tooth
compass saw and cut by hand and keep a small box on top of the ladder to
catch the bulk of the dust. *I am always afraid of cutting into wires and
pipes with the power tools.

A 9" hole is quite big for recessed lights. *Are you installing commercial
fixtures?

Thanks, the attic above is real tight I cannot get to it from above
for most of the lights. I have to deal with it from below.

I am not installing 9" housings. I am installing 5" housings. I am
saying to use the shielded hole cutter to cut a large hole so I can
have access to remove old housing and mount new ones (not the remodel
kind).

The problem is even if I can knock out the old can the existing holes
are too big, the existing holes are 6-3/4" for the old housing and
this is too big for the new housing anyways. I doubt I can mount a
smaller remodel can onto a larger hole. So my thinking is to make the
biggest hole possible, mount the new lights to the joists through the
9" hole (if possible, but I am really uneasy about this, I think I
might end up having to cut a 16"x16" square hole).

MC