I own two stud finders and neither is giving me consistent results. Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. Symmetry is important. Would like to put in 14" diameter daylight tubes so joist placement is important.
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. This is throughout the house and is probably why the stud finders are not consistent. Complicating this is the fact that the joist are all over the place and not necessarily parallel. I have a few 13" gaps and a few 17" gaps etc. I know this from measuring up in the attic. Further difficulty is that I have about 24" of blown in insulation. If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below. Can't shove the awl through the plywood! So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. Needs to be repeated at the other end which takes just as many tries. The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. All together I have about 48 locations to do. Way to slow.

All alternative ideas appreciated. You're welcome to call me an idiot if it pleases you. Just help me save some time and effort.

Ivan Vegvary

P.S. I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

Ivan Vegvary wrote:
I own two stud finders and neither is giving me consistent results.
Need to find all of the ceiling joists in my kitchen so I can install
2 light tubes and 18 can lights. Symmetry is important. Would like
to put in 14" diameter daylight tubes so joist placement is
important.
My problem is that the ceiling consists of 1/2 inch drywall under 1/2
inch plywood. This is throughout the house and is probably why the
stud finders are not consistent. Complicating this is the fact that
the joist are all over the place and not necessarily parallel. I
have a few 13" gaps and a few 17" gaps etc. I know this from
measuring up in the attic. Further difficulty is that I have about
24" of blown in insulation. If I had drywall only (you lucky
*******s) I would simply go in the attic and shove an awl down along
side each joist, and then run chalk-lines down below. Can't shove
the awl through the plywood! So I'm working down below on a ladder
with a yogurt can attached to my portable drill (wife doesn't like
dust) and it takes me about 6-7 holes to locate a single edge of a
joist. Needs to be repeated at the other end which takes just as
many tries. The next joist can be measured out 16 inches and still
takes about 5 holes due to irregular placement. All together I have
about 48 locations to do. Way to slow.

All alternative ideas appreciated. You're welcome to call me an
idiot if it pleases you. Just help me save some time and effort.

You need a very powerful small magnet - like the ones I took out of old 5 1/4"
harddrives. They will quickly find the nails into the joists. They will probably
stick to them. I use them to find the joists on my lath and plaster walls and
ceilings. Of course, if the drywall is not nailed at the joists, this will
confuse things, but the magnets should still pull at least gently on the nails
1/2" away. If it sticks hard, that's probably a drywall nail. If it pulls just a
little, that's a plywood nail.

It seems you could just measure below, since with the plywood, you can hang
lights anywhere.

On Sat, 27 Aug 2011 20:13:53 -0700 (PDT), Ivan Vegvary
wrote:

I own two stud finders and neither is giving me consistent results. Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. Symmetry is important. Would like to put in 14" diameter daylight tubes so joist placement is important.
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. This is throughout the house and is probably why the stud finders are not consistent. Complicating this is the fact that the joist are all over the place and not necessarily parallel. I have a few 13" gaps and a few 17" gaps etc. I know this from measuring up in the attic. Further difficulty is that I have about 24" of blown in insulation. If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below. Can't shove the awl through the plywood! So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. Needs to be repeated at the other end which takes just as many tries. The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. All
together
I have about 48 locations to do. Way to slow.

Since you can get to the top side, instead of an Awl to make the marking
holes, use a drill.

I'd try the magnet idea first, though.

All alternative ideas appreciated. You're welcome to call me an idiot if it pleases you. Just help me save some time and effort.

Ivan Vegvary

P.S. I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

On Aug 28, 4:13*am, Ivan Vegvary wrote:
I own two stud finders and neither is giving me consistent results. *Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. *Symmetry is important. *Would like to put in 14" diameter daylight tubes so joist placement is important. *
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. *This is throughout the house and is probably why the stud finders are not consistent. *Complicating this is the fact that the joist are all over the place and not necessarily parallel. *I have a few 13" gaps and a few 17" gaps etc. *I know this from measuring up in the attic. *Further difficulty is that I have about 24" of blown in insulation. *If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below.. *Can't shove the awl through the plywood! *So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. *Needs to be repeated at the other end which takes just as many tries. *The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. *All together I have about 48 locations to do. *Way to slow.

All alternative ideas appreciated. *You're welcome to call me an idiot if it pleases you. *Just help me save some time and effort.

Ivan Vegvary

P.S. *I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

Tap the cieling with a hammer. Sounds different where the joists are.
Works with ply, not with drywall.

On 8/27/2011 11:13 PM, Ivan Vegvary wrote:
I own two stud finders and neither is giving me consistent results. Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. Symmetry is important. Would like to put in 14" diameter daylight tubes so joist placement is important.
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. This is throughout the house and is probably why the stud finders are not consistent. Complicating this is the fact that the joist are all over the place and not necessarily parallel. I have a few 13" gaps and a few 17" gaps etc. I know this from measuring up in the attic. Further difficulty is that I have about 24" of blown in insulation. If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below. Can't shove the awl through the plywood! So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. Needs to be repeated at the other end which takes just as many tries. The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. A
ll together I have about 48 locations to do. Way to slow.

All alternative ideas appreciated. You're welcome to call me an idiot if it pleases you. Just help me save some time and effort.

Ivan Vegvary

P.S. I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

1. Get a piece of steel bar stock, say a couple feet long, and shove it
down through the insulation and lay it beside the joist, up tight
against it. That should give enough of a mass for your stud finders to
give a good reading. If not, borrow/buy/rent a low-end metal detector.
It'll hit on it. Or like the other guy said, some high-strength magnets.
Two points a couple feet apart will be enough to plot that joist across
the whole room.

2. Go look at the laser levels, including the spinning ones. Some also
work mounted sideways, and could 'paint' a line on both sides of a beam
from a tripod centered below the beam. The cheap alternative that I
would use for a single project is a small framing square , to make
witness marks on either side of beam, and carry them around the beam. Do
your joists run across the beam, or are they lapped there? Projects like
this are where high school geometry comes in handy.

3. For the solatubes, drill pilot holes up from below, and shove a piece
of piano wire straight up, and measure how far you are from nearest
joist. The tubes do not have to be straight up and down. Adjust your
layout till you find spots that are pleasing to the eye from below, and
clear the joists. Any pilot holes that are too far off will be easy to
patch with a dab of putty- you are gonna end up painting the ceiling anyway.

4. Having said all that, I would be hesitant to put that many holes in
an insulated ceiling. You do know all the lights will need the special
shrouds above them, and will still be heat loss points, right? I'd be
much more inclined to use pancake boxes recessed into the drywall and
screwed to the plywood, and use shallow surface-mounted cans, or even
puck lights. It'd still be a PITA daisy-chaining the lights through that
sea of insulation, but a lot less work than 20 big holes with drifts of
insulation coming down.

--
aem sends...

On Aug 28, 6:23*am, aemeijers wrote:

4. Having said all that, I would be hesitant to put that many holes in
an insulated ceiling. You do know all the lights will need the special
shrouds above them, and will still be heat loss points, right?

SURELY in these days, CFL'S will be used, and venting requirements
based on incandescents would not be applicable.
But the units still have their "Maximum 60 watts" stickers. Or more.
I would like to see replacement stickers that would be put over that
would say "Maximum 14 watts" or whatever.

On 8/28/2011 6:37 AM, Michael B wrote:
On Aug 28, 6:23 am, wrote:

4. Having said all that, I would be hesitant to put that many holes in
an insulated ceiling. You do know all the lights will need the special
shrouds above them, and will still be heat loss points, right?

SURELY in these days, CFL'S will be used, and venting requirements
based on incandescents would not be applicable.
But the units still have their "Maximum 60 watts" stickers. Or more.
I would like to see replacement stickers that would be put over that
would say "Maximum 14 watts" or whatever.

Unless code has been changed, the requirement still exists. Next owner
may not like CFLs, and put old-style bulbs in there. Now if he went with
something exotic where regular bulbs would not fit, it might be different.

--
aem sends...

On 8/27/2011 10:13 PM, Ivan Vegvary wrote:
I own two stud finders and neither is giving me consistent results.
Need to find all of the ceiling joists in my kitchen so I can install 2
light tubes and 18 can lights. Symmetry is important. Would like to put
in 14" diameter daylight tubes so joist placement is important.
My problem is that the ceiling consists of 1/2 inch drywall under
1/2
inch plywood. This is throughout the house and is probably why the stud
finders are not consistent. Complicating this is the fact that the joist
are all over the place and not necessarily parallel. I have a few 13"
gaps and a few 17" gaps etc. I know this from measuring up in the attic.
Further difficulty is that I have about 24" of blown in insulation. If I
had drywall only (you lucky *******s) I would simply go in the attic and
shove an awl down along side each joist, and then run chalk-lines down
below. Can't shove the awl through the plywood! ...

A) Bell-installer bit (or use an extension bit holder) and drill along
the joists from the attic; nothing says you have to be able to punch the
hold manually.

B) Measure (consistently) from one end to other in the attic the
location of each joist and transfer the measurements to below.

C) Just place openings where want them from function and aesthetics and
deal with it as needs be by boxing any joists that do need it after the
fact...

--

"Ivan Vegvary" wrote in message
...
I own two stud finders and neither is giving me consistent results. Need to
find all of the ceiling joists in my kitchen so I can install 2 light tubes
and 18 can lights. Symmetry is important. Would like to put in 14"
diameter daylight tubes so joist placement is important.
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch
plywood. This is throughout the house and is probably why the stud finders
are not consistent. Complicating this is the fact that the joist are all
over the place and not necessarily parallel. I have a few 13" gaps and a
few 17" gaps etc. I know this from measuring up in the attic. Further
difficulty is that I have about 24" of blown in insulation. If I had
drywall only (you lucky *******s) I would simply go in the attic and shove
an awl down along side each joist, and then run chalk-lines down below.
Can't shove the awl through the plywood! So I'm working down below on a
ladder with a yogurt can attached to my portable drill (wife doesn't like
dust) and it takes me about 6-7 holes to locate a single edge of a joist.
Needs to be repeated at the other end which takes just as many tries. The
next joist can be measured out 16 inches and still takes about 5 holes due
to irregular placement. All together I have about 48 locations to do. Way
to slow.

All alternative ideas appreciated. You're welcome to call me an idiot if it
pleases you. Just help me save some time and effort.

Ivan Vegvary

P.S. I have about 48 findings not because the kitchen is huge, but because
a steel beam runs down the middle of the room below the the ceiling and I
cannot run a chalk line through it.


Long thin drill bits no more than 1/8" wide by up to 2 foot long are sold.
A heavy wire coat hanger cut with pliers to a point works almost as well
even through wood.

I would pick a central or important location and find the ends of that
rafter. Careful measuring in the attic, transferred to masking tape on the
ceiling below will get you within 3/4" of the location of the remaining
joists. Another 1/8" hole can be drilled at each penetration point for
confirmation.

1/8" holes in any material are easy to fill.


--
Colbyt
Please come visit http://www.househomerepair.com

On Aug 27, 10:13*pm, Ivan Vegvary wrote:
I own two stud finders and neither is giving me consistent results. *Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. *Symmetry is important. *Would like to put in 14" diameter daylight tubes so joist placement is important. *
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. *This is throughout the house and is probably why the stud finders are not consistent. *Complicating this is the fact that the joist are all over the place and not necessarily parallel. *I have a few 13" gaps and a few 17" gaps etc. *I know this from measuring up in the attic. *Further difficulty is that I have about 24" of blown in insulation. *If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below.. *Can't shove the awl through the plywood! *So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. *Needs to be repeated at the other end which takes just as many tries. *The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. *All together I have about 48 locations to do. *Way to slow.

All alternative ideas appreciated. *You're welcome to call me an idiot if it pleases you. *Just help me save some time and effort.

Ivan Vegvary

P.S. *I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

Is the drywall nailed or screwed to the plywood, if screwed, is there
a discernable pattern? Have you tried a bright light shining
parallel to the ceiling right at the ceiling, to show up any nail
heads? Otherwise, a pointy coathanger wire in the end of an electric
drill should go up thru the sheetrock and any reasonble plywood making
for easy drilling and any subsequent patching. Unless this is an
antique farm house, ceiling studs are generally 16" on center due to
building codes and building inspectors.

On Aug 28, 4:28*pm, "hr(bob) "
wrote:
On Aug 27, 10:13*pm, Ivan Vegvary wrote:

I own two stud finders and neither is giving me consistent results. *Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. *Symmetry is important. *Would like to put in 14" diameter daylight tubes so joist placement is important. *
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. *This is throughout the house and is probably why the stud finders are not consistent. *Complicating this is the fact that the joist are all over the place and not necessarily parallel. *I have a few 13" gaps and a few 17" gaps etc. *I know this from measuring up in the attic. *Further difficulty is that I have about 24" of blown in insulation. *If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below. *Can't shove the awl through the plywood! *So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. *Needs to be repeated at the other end which takes just as many tries. *The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. *All together I have about 48 locations to do. *Way to slow.

All alternative ideas appreciated. *You're welcome to call me an idiot if it pleases you. *Just help me save some time and effort.

Ivan Vegvary

P.S. *I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

Is the drywall nailed or screwed to the plywood, if screwed, is there
a discernable pattern? * Have you tried a bright light shining
parallel to the ceiling right at the ceiling, to show up any nail
heads? *Otherwise, a pointy coathanger wire in the end of an electric
drill should go up thru the sheetrock and any reasonble plywood making
for easy drilling and any subsequent patching. *Unless this is an
antique farm house, ceiling studs are generally 16" on center due to
building codes and building inspectors.

Heh Heh. They are/were 16" over here too. (UK) I suppose it is one
third the width of ply/plaster sheets.
400mm now.

You need a very powerful small magnet - like the ones I took out of old 5 1/4"
harddrives. They will quickly find the nails into the joists. They will probably
stick to them. I use them to find the joists on my lath and plaster walls and
ceilings. Of course, if the drywall is not nailed at the joists, this will
confuse things, but the magnets should still pull at least gently on the nails
1/2" away. If it sticks hard, that's probably a drywall nail. If it pulls just a
little, that's a plywood nail.

It seems you could just measure below, since with the plywood, you can hang
lights anywhere.

Thanks for the advice. The lights will all be recessed, so they have to go between studs. Not difficult to find six inch space between 16"± studs. However I would like to place 14" daylight tubes (2) and that only leaves about 1/2 inch of clearance. I will try the magnet scenario.

Thanks again, Ivan Vegvary

I'll try tapping. Thanks for the advice.

Ivan Vegvary

The drill idea from above seems the fastest and surest. As suggested further down I could get an electricians long bit and thereby be able to tuck up adjacent to the joist.

Thanks, Ivan Vegvary

I like the bar stock idea. Have plenty of 5/8" square tubing on hand along with short pieces of 3/4" pipe. More aluring however, is your idea of using 'puck lights'. We didn't want too much of projection into the room (e.g.. track lights) but I will look for lights that are minimally invasive.

Thank you, Ivan Vegvary

An electrician's bit and working from above might be the fastest. Miserable conditions up there. Vertical clearances are as low as 8". Additionally, half of the kitchen has a double roof over the ceiling. There has been an addition done and instead of removing the old roof they simply build another one above. W(Out West this method is called a 'California Roof').

Anyway, drilling from above and accurately measuring and diagramming from the attic should save a lot of time.

Thanks, Ivan Vegvary

On Sun, 28 Aug 2011 10:18:52 -0700 (PDT), Ivan Vegvary
wrote:

The drill idea from above seems the fastest and surest. As suggested further down I could get an electricians long bit and thereby be able to tuck up adjacent to the joist.

Just remember which side of the joist you drill on. ;-) My suggestion is to
remember N/S, or E/W, or perhaps "on the driveway side" (not L/R).

On Aug 27, 11:13*pm, Ivan Vegvary wrote:
I own two stud finders and neither is giving me consistent results. *Need to find all of the ceiling joists in my kitchen so I can install 2 light tubes and 18 can lights. *Symmetry is important. *Would like to put in 14" diameter daylight tubes so joist placement is important. *
My problem is that the ceiling consists of 1/2 inch drywall under 1/2 inch plywood. *This is throughout the house and is probably why the stud finders are not consistent. *Complicating this is the fact that the joist are all over the place and not necessarily parallel. *I have a few 13" gaps and a few 17" gaps etc. *I know this from measuring up in the attic. *Further difficulty is that I have about 24" of blown in insulation. *If I had drywall only (you lucky *******s) I would simply go in the attic and shove an awl down along side each joist, and then run chalk-lines down below.. *Can't shove the awl through the plywood! *So I'm working down below on a ladder with a yogurt can attached to my portable drill (wife doesn't like dust) and it takes me about 6-7 holes to locate a single edge of a joist. *Needs to be repeated at the other end which takes just as many tries. *The next joist can be measured out 16 inches and still takes about 5 holes due to irregular placement. *All together I have about 48 locations to do. *Way to slow.

All alternative ideas appreciated. *You're welcome to call me an idiot if it pleases you. *Just help me save some time and effort.

Ivan Vegvary

P.S. *I have about 48 findings not because the kitchen is huge, but because a steel beam runs down the middle of the room below the the ceiling and I cannot run a chalk line through it.

tear down the cieling for maximum symmetry placement.

otherwise you are just screwing around and theres a big likelyhood of
unknown obstructions

like water sewer fireblocks joists at wierd spots etc etc.

or go with surface mounted fluroscent fixtures that will be easier to
adjust location of.....