She who must be obeyed would like gobs of outlets in her office.
I plan on surface mounting these to the block walls using metal handi boxes and emt.
Tapcons seem to have generated both good and bad responses in the forum and I was considering using 1/4 tapcons in plastic inserts; a kind of belt and suspenders arrangement. Callbacks are not an option.
Are tapcons in inserts the way to go; I dont mind the additional expense or the extra time involved.
Also how difficult is pulling wires through emt; these will be your equivalent of 20A
Thanks,
Hank.
Replies
Hank,
Skip the tapcons and just use sheet metal tapping screws. #10 PHP screws into #8 - 10 blues.
Have fun!
If you are using Tapcons you won't need the inserts unless you strip out a hole. Use a hammerdrill, go deeper than the screw length and use 1/4" x 1 1/4" screws. 3/16" in block strips out too easily.
Have you considered using the grey PVC conduit, fittings and boxes? The install would go a lot easier. Don't need a bender. Just cut to length and glue on the sweeps and boxes. Suck a string through with your shop vac and pull back the wires.
The nice thing about Tapcons is the ease and speed of instalation.
1. You put what you want attached where you want it.
2. You grab your drill with the correct masonry bit in it and drill the hole right through the hole.
3. You drive the scew in the hole. You're done!
If the Tapcon screw is hard to drive in run the masonry bit in the hole again. If it still is tight then run it in a little angled to enlarge the hole a bit more. After a while you will have it down.
With plastic anchors you will have a lot more steps and it won't be as strong. When the tapcons are installed correctly they won't pull out. Ever! They would break first.
Been reading up on the tapcons from Buildex.
They say use their "close tolerance" bit.
I have a Bosch SDS bulldog drill with 3/16 bit; is this bit close enough for 1/4 tapcons?
Also can you buy single wires to pull through emt or do you have to strip your own?
Thanks,
Hank.
Try drilling a hole and then driving the screw to see if it is right. I just finished a project with a screw that wasn't made for a bit. I wanted to use these screws because I had them and the head matched the rest of the project.
I ended up using a bit that was to small so I just reamed the hole out with the bit by going in and out several times with the bit angled a little to the side.
Then I would try to drive the screw. If it was tight I backed it out and drove it in again again until it drove all the way. Every time you drive it in it goes a little further.
Another thing you can do is to take a dremel to your masonry drill bit. Take some of the carbide off the sides of your masonry bit and then do a test hole. See if you have taken off enough. Keep reducing the dia. of the bit until you get a good grab with your screw.
You can get 250' spools of at any electric supply house or even Lowes or HD. I'm not sure but the big boxes likely sell it by the foot. If you are wiring 20 amp circuites ask for # 12 THN or THHN. One each black, white and green. My personel preferance is stranded wire for pulling long runs or runs with more than one bend, Some guys like solid wire because you can just push it through short pulls and it is easier to make up on most devices. I always use spec grade devices with thewire clamp scews, so stranded is nevera problem for me.
Set up a ladder with a piece of emt laying across the braces. Slide all three spools on the emt and pull away. It is also a good idea to have a second set of hands to feed the wire into the pipe as you pull the fish tape or string line. They keep the enevitable tangle straighten out and also keep the wire from getting skinned up as it goes in.
That is right, 3/16 for 1/4 and 5/32 for the 3/16. Some of the generic/cheaper bits tend to drill a little large and make sure it is not bent, that will oversize the hole also.
I have only had trouble with old mortar, old brick, some cruddy block. Generally great results with tapcons or "tappers" from Rawl I believe. I have not had very good exp with the Wall Dogs". To be fair the last attempt (yesterday) was a 45 yr old church with plaster over concrete block and I used a cheapo bit that probably was the problem. I ended up sticking toothpicks in the holes to get some grab.
wiring for 20 amp circuits wont be hard to pull, you have to use 12 guage single conductors and if its not too long a run you shouldnt need a fish.
Unless you plan on pulling a lot of wires.
You could always use wire lube if need be.
"You could always use wire lube if need be."
I believe wire lube is always used regardless of how many conductors are pulled. The idea is that the lube prevents friction from burning through the wire's insulation layer.
Electricians, please pipe in if I'm wrong about this.
I used to use Tapcons and had lots of trouble with them. One time, I was out at a jobsite and a guy there was using split-drive fasteners. That's all I use now. Just rotohammer the hole and hammer them in. I've yet to have one get messed up.
The only downside is that they aren't designed to be removed (although I have removed a couple on occasion when it was required).
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http://www.concretefasteners.com/anchors-fasteners/split-drive/index.aspx
using metal handi boxes and emt.
Skip that stuff and use plugmold strips. Easier, better looking, offers more outlets.
Tapcons - the "blue screws" - don't work so well on cement blocks. Save them for real cement / concrete.
Ordinary #10 screws, with the associated plastic anchors, work just fine. I've also had success with "wall dogs" (#10 screws with HUGE threads, made for just this).
Pulling a single circuit in 1/2" EMT ought to be quite easy. I recommend using 4" square boxes, and if the receptacles are GFI's, using the 'deep' ones. You'll appreciate the wire space inside.
Tapcons - the "blue screws" - don't work so well on cement blocks. Save them for real cement / concrete
Huh?
I have used them in light weight block for years and seldom have a problem. Using the correct length is crucial for installations on block, as is the right size bit.
Someone mentioned 1 1/4" as the size to use. They are correct. If the screw is to long it will finish blowing out the back of the hole and only leave a couple of threads biting into the block.
I have never pulled a box off of a block wall or concrete when mounted with tapcons. I can't say the same for plastic anchors. The key to drilling the hole is easing up with the pressure and speed as the bit nears the back of the block. You get very little blow out and end up with an 1" or better surface for the tapcon to thread through. If you can line up the hole over a web, so much the better, you don't have to worry about blow out.
Plastic anchors in block are ok but it involves a third step; drill, insert anchor, drive in the screw. With tapcons you just drill and drive.
If you go to tapcons web site, you can see the rating for shear and withdrawal. It is magnitudes higher than plastic anchors and panhead screws, not that he will need that kind of performance in this application, but it is there.
I wonder if some of the trouble people have with "Tapcons" is due to using a generic brand. I once used generic concrete screws - they were junk.-T
I've had far too many tapcons strip their the threads that they have made in either block, or soft 'terra cotta' brick. Even the 'good' threads are useless after one use; there's no removing and re-inserting the screw. Now, it is possible that the masonry pieces we have here are of a shabbier quality than what you are encountering; Reno brick & block sure isn't the same as Chicago brick & block!
A soft substrate definitely calls for plastic anchors or molybolts (winged type).
I absolutely gring when we run into that old soft terra cotta stuff. The glazed stuff is the worst. Sometimes just drilling it will crack the whole block.
renosteiknke--do you have a brand name or supplier for the #10 'wall dogs'? We are forever fastening to block/terracotta/gypcrete walls and are searching for a better way...
wall dog http://www.amazon.com/Hillman-Fasteners-42005-20PK-Wall/dp/B000ODQI8Gavailable at home depot / lowes also we use them mainly for drywall
I believe the ones I used - they are no longer carried by the supply house - were made / distributed by Dottie. They will turn up in a Google search, in a few variations. The ones I used had a diamond-shaped point, and extremely pronounced threads. Contrary to their 'use on everything' marketing, I found them best when used in the appropriate pilot hole in block or soft brick.
http://www.powers.com/product_2314.html
The wiremold and plugmold will look better.
My experience, if you are having trouble with Tapcons, you are not drilling the hole deep enough. The screw cuts a chip, which is pushed ahead of the point of the screw. You need to be at least 1/4" deeper than the screw length.
That aside, they work great for me.
Dave Richeson is about as right as can be on this topic. The one secret I can add is to install them by hand. Remember that thing that did everything before the battery drill? Makes a big difference if you've been having problems.
I learned that at an installation school a few months back. We were building security vestebules and the instructor didn't have one power tool.
Pop, lock, and drop it.
http://www.youtube.com/watch?v=c5K8sofXj5E
He who wants a little piece and no hard time should look at the proper surface mount materials.
Emt is just plain ugly. Look in lowes or HD they have sections with what you need.
She who must be obeyed will be much happy.
And I would use the plastic plugs and screws in cinder block.
You can't beat fischer or hilti wall plugs, fast and easy to install. I prefer them over tapcons, I didn't have good results with them. MartinInteresting fischer commercial: http://www.youtube.com/watch?v=aRoLj6_CJIE
Thanks for all the help and suggestions.
We now have lots of info to make decisions.
Hank.