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LazMan
Premium
join:2003-03-26
canada
reply to Subaru

Re: Drilling into concrete ceiling

Tapcons FTW... Sleeve or expanding anchors would work, but are WAY beyond overkill for this application.

If you have to put that much pressure on your drill, you've got either a crappy bit, or a crappy drill... I'm a Hilti guy, myself, my TE-5 is 10 years old, and works amazing - can drill 5/8" holes all day... Key is a good bit!

You can get a small package of Tapcons with the proper sized bit for few bucks - the bit's not great, but for 2 or 4 holes, it'll be fine. Be sure to hold the drill square to the ceiling, have good footing, and don't let it wander.

BTW - what kind of space are you mounting it in, that you've got a concrete ceiling?



Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18
reply to Jack_in_VA

said by Jack_in_VA:

said by Juggernaut:

And, depending on the concrete, expect to use one bit per hole.

If I had to use one bit per hole I would have bankrupted the company.

Agree. I have masonry bits that are still good after 10+ Years and 100's of holes. Buying quality bits pays hidden dividends like longer life than one use.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?

MaynardKrebs
Heave Steve, for the good of the country
Premium
join:2009-06-17
kudos:4
reply to Subaru

Watch out for electrical conduit embedded in the concrete (not knowing what the 'ceiling' is the floor of above you).

How thick is the ceiling slab? If it isn't really thick (8"+), don't use expanding anchors - use Tapcons, or threaded rod anchored in epoxy. If using rods, use lock nuts to hold the projector onto the rods.



Westofhere

join:2005-04-07
West Coast
reply to Subaru

OP, make sure you are not drilling into a post-tension layer. If you hit one of the cables in the concrete it will not end well for you.
»www.concreteconstruction.net/con···abs.aspx

If you are not in a post-tension layer, these are the best anchors I have used. »fasteners.stanleysupplyonline.co···-anchors

We use them to hold all sorts of HVAC mechanical equipment/ ducting. Far better than having to try and pound in a drop-in over your head.



Juggernaut
Irreverent or irrelevant?
Premium
join:2006-09-05
Kelowna, BC
kudos:2
reply to Doctor Olds

I would have thought that Bosch bits were good quality for the price I paid. But I do agree. I don't cheap out on equipment for the same reason. It's false economy to do otherwise.
--
I'm not anti-social, I just don't like stupid people.



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Westofhere

This building is old from the early 60's I think.. so does post-tension still apply?

nm saw the link dates



Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ

1 recommendation

reply to EGeezer

said by EGeezer:

Just curious - How does one avoid hitting a reinforcing rod? I'd hate to start drilling then be stymied by one of those.

one doesn't avoid rebar. you just make a new hole.

there are devices to sense rebar but they are too expensive for me.


Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Subaru

Well I now know how thick the ceiling is.. had some work done so I'd say it's about 1/2" or so.


bemis

join:2008-07-18
Reading, MA
Reviews:
·Comcast

Sounds like what I had in my basement... 1/2-3/4" thick concrete on a metal mesh?

I'd drill holes large enough to use toggle bolts. If you have the height, you could consider mounting a piece of wood up there, like a short length of 2x8 which you could secure very strongly up there on it's face using a combo of liquid nails and toggle bolts, then mount the projector to the 2x8...


sk1939
Premium
join:2010-10-23
Mclean, VA
kudos:10
reply to Subaru

Lots and lots of super glue.

On a more serious note, tapcons are probably the most effective, bulding a wood frame and base would look nicer but would take longer with questionable gains in terms of weight it holds.



Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to Subaru

said by Subaru:

Well I now know how thick the ceiling is.. had some work done so I'd say it's about 1/2" or so.

.........so it's cement board on studs? if so, get the stud centers and mount two 2x4's spanning at least two studs, spaced so the projector will fit over them, and fasten your projector to the 2x4's.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

It's plaster. No tapcons. My first choice would probably be molly bolts. Be sure to run this by the landlord. Plaster is not as easy to repair as sheetrock.



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Sc0tt

said by Sc0tt:

said by Subaru:

Well I now know how thick the ceiling is.. had some work done so I'd say it's about 1/2" or so.

.........so it's cement board on studs? if so, get the stud centers and mount two 2x4's spanning at least two studs, spaced so the projector will fit over them, and fasten your projector to the 2x4's.

You don't really understand I had exhaust fan installed in the bathroom which required a square hole cut so that's how I was able to see the thickness..

the best way would to just use the tapcons.
--
It's NOT Ni-kon It's NE-KON!




LG is NOT Lifes Good It's Lucky Goldstar!


robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

So what is the ceiling made of? Did you take any pics? Do you have the piece that was cut out?



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

Yeah I will get some pictures in a few, it's hard to say I'm not sure how laying concrete for a ceiling is and what they use for a base but it looks like it was poured.



Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to Subaru

said by Subaru:

You don't really understand I had exhaust fan installed in the bathroom which required a square hole cut so that's how I was able to see the thickness..

the best way would to just use the tapcons.

I do understand. I also know the entire ceiling can't be floating from only the perimeter of the room. there must be studs holding the 1/2" thick material or it would simply collapse.

tapcons are great in concrete----not so much in cement BOARD.


Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

When the hole was open I did not have time to peak above and look around that might be a little hard to do now since the exhaust fan is installed and all.

but here is a picture.

Looks like it might be cement board? It has a wire screen above it from what I can see.


robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

Just as I guessed -- it's plaster on metal lath. Use molly bolts.



John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:6

said by robbin:

Just as I guessed -- it's plaster on metal lath. Use molly bolts.

This. ^

For best results, make the holes carefully. You don't want to blow out the backside of the material by just hammering something through it. Doing that disrupts the integrity of the material surrounding the hole and reduces the support capacity.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

I wouldn't even use a hammer drill on it. Tape off the spot you want to drill so it doesn't chip out too bad and use a masonary bit in a regular drill at a slow speed. Start with a smaller drill bit because if you start with one sized for the Molly bolt guaranteed you will find the joist and only need to use a screw.



AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
reply to Sc0tt

said by Sc0tt:

i have a hilti te-7c. it will drill into anything, including steel water pipes

Cutting steel is easier than concrete.
--
* seek help if having trouble coping
--Standard disclaimers apply.--


AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
reply to MaynardKrebs

said by MaynardKrebs:

Watch out for electrical conduit embedded in the concrete (not knowing what the 'ceiling' is the floor of above you).

How thick is the ceiling slab? If it isn't really thick (8"+), don't use expanding anchors - use Tapcons, or threaded rod anchored in epoxy. If using rods, use lock nuts to hold the projector onto the rods.

i would never use chemical anchors in tension.
--
* seek help if having trouble coping
--Standard disclaimers apply.--

MaynardKrebs
Heave Steve, for the good of the country
Premium
join:2009-06-17
kudos:4

said by AVD:

said by MaynardKrebs:

Watch out for electrical conduit embedded in the concrete (not knowing what the 'ceiling' is the floor of above you).

How thick is the ceiling slab? If it isn't really thick (8"+), don't use expanding anchors - use Tapcons, or threaded rod anchored in epoxy. If using rods, use lock nuts to hold the projector onto the rods.

i would never use chemical anchors in tension.

He's talking about installing a 12lb. load with probably 3-6 anchors locating in a relatively small area (almost certainly less than 1 sq. ft., and more likely about 1/2 that area). That many expansion anchors in that small an area is just asking for cracking & spalling of the concrete.


PeeWee
Premium
join:2001-10-21
Madera, CA
reply to Subaru

There is a high likelihood of asbestos in that type of ceiling.
--
Iphone. Helping computer illiteracy become popular since 2007



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

yeah that could be a possibility



Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to AVD

said by AVD:

said by Sc0tt:

i have a hilti te-7c. it will drill into anything, including steel water pipes

Cutting steel is easier than concrete.

yes, with the proper tools. I am in construction and work with both daily.

it was a hammer drill bit (sds+ to be exact) that was put through the standpipe LOL.