Fastening Into Concrete?

[jyl]

I've got some projects coming that may require fastening into concrete. Not heavy loads.

What are the easiest ways to do this? Concrete drill - do you buy or rent these, how long and how much swearing per fastener, any skill required? Powder-actuated tool - same questions?

[dan88911]

Not a big deal jyl. You may want to visit your local Homedepot. They should some anchors on display with some infor. on application. And a tool rental shop.

[fred cook]

The best way to anchor to a new slab is to set J hooks before the slab is poured. This is done by placing a board along the edge of the slab with holes drilled in it. The J hooks are mounted in the board with the hook end down in where the slab will be located. Then, when the concrete is poured and cured, the nuts can be removed from the J hooks and the support board removed. Now, the hooked ends are firmly set in the concrete. Now all you have to do is drill matching holes in your bottom plate (wood or steel) to match the spacing of the J hooks, set in place, add appropriately sized washers and tighten down the nuts. If you wish, you can build the wall on the slab, add the holes in the bottom plate and then tip the wall up into place and fasten as described above.

Good luck with your project!

Tapcon brand fasteners. Home centers will have.

[jyl]

"The best way to anchor to a new slab is to set J hooks before the slab is poured."

Darn, should'a told them that in 1910 :-)

Seriously, thank you guys all, for the help. Now I'm not going to use sticky tape or repour the slab (just to mention two extremes . . . )

PPOT - the world's most helpful water cooler!

[kach22i]

Drill hole and epoxy grout in.

[sc_rufctr]

A regular hammer drill and masonry bit will will easily drill concrete.

Heat is the enemy of masonry drills so you need at least two so one can cool down as you use the other.
Depending on the size of the hole you may want to step up in sizes to get to the final size.
So if you're drilling a final hole of 12mm, I would use and 8mm first then finish with a 12mm.

You have several fastening systems to choose from but here's a run down on the three most common types.

1. Expansion bolts. These are good but can be tricky to install and if not done right can pull out.
The drill hole has to be the right size and if you're drilling into brick you could hit a void which makes the bolt useless.
There's a nut on the exposed end and when you tighten this nut it pulls the bolt back towards you expanding the out sleeve.
They are called "Dynabolts" locally... Not sure about the US.

2. Screw type fasteners: These are a hardened, galvanized steel fasteners with a largish outer thread with a sharp edge.
They work really well and are the strongest option but you need to get a lot of torque on them to bite into the concrete as you screw them in.
They have a bolt head on them so they are not as versatile as the ""Dynabolts".

3. Plastic Plugs and screws: Probably the easiest of the three to install but also the weakest.
You dill a hole, Clear it out, Insert a plastic plug, Then screw in a steel screw that bites into the plastic plug expanding it in the concrete.

The holes have to be the right size for all three systems and you need a blast of compressed air to clear out the holes once drilled. (Wear eye protection)
Go slow at first and "learn" how to do it in your circumstance. It's really not hard.

You can rent a hammer drill press that has a retracting right angle foot. The steel version of this drill has an elecro magnetic foot.
But unless you have hundreds of holes to drill I wouldn't bother. A regular hammer drill will do the job.

[jyl]

Would it be easier to use a nail gun, excuse me powder actuated tool?

Btw, I'm sorry for starting two identical threads, was an accident. I was going to delete one, but didn't catch it in time.

[eastbay]

Tapcon screws are the shizzle, and use the Tapcon drill bits that fit them

[sc_rufctr]

Originally Posted by jyl

Would it be easier to use a nail gun, excuse me powder actuated tool?

Btw, I'm sorry for starting two identical threads, was an accident. I was going to delete one, but didn't catch it in time.

That depends on the job. What are you planning to do?

There is a forth option. Hardened steel pins driven into prepared holes with a sledge hammer.
The pins have a profiled outer surface that is designed to grip into concrete in a similar way a barb fitting grips to the inside of a rubber hose.
These can not be removed without destroying the hole in the concrete.

[trekkor]

Red Head


KT

[Icemaster]

What are you trying to fasten? Tapcon's work for most needs. You can get a full kit that has the appropriate bit. A simple hammer drill will work for that application. Borrow or rent.

[VINMAN]

What do you have to fasten? and is it to a wall? floor?

[Dantilla]

Originally Posted by jyl

Darn, should'a told them that in 1910 :-)

Powder-actuated fasteners will not work with concrete that old.

[MotoSook]

Just installed a lift in the barn (2nd time I've installed this lift). Ten 3/4" holes with a $69 hammer drill (Ryobi from Home Depot) and the cheapest bit they had ($9 versus $39 for a Bosch branded one). I also had a bit from the last time I installed the lift. I started with the old bit and it was slow going. After 2 holes 20+ minutes each, I swapped out the bit and the new one took maybe 5 minutes per hole. Not bad for 3/4" holes 5 inches deep in very well placed concrete...good concrete.

I used REDHEADS (mechanical anchors) but I also used expoxy. I clean the holes well with a wire brush and a vacuum (1/2"'conduit attached to the end of the vacuum hose. Then I squeezed some ($15 tube) epoxy in the holes before I tapped the anchors in. The epoxy will do a better job of spreading the load within the hole and the mechanical aspect of the anchor will work with the epoxy to make the bolt immoveable.

I put a little tension of the bolt and let the epoxy cure. Next day I toque the nuts on the anchors and its solid as can be.

So if you have a bug job..I'd recommend the above. I'd still do that with smaller anchors because it's fairly easy to do bow that I have the big hammer drill.

[look 171]

I second Redhead anchors. Tapcon will do sometimes. What are you doing?

[jyl]

For example, sill plates on a concrete basement floor.

[look 171]

Do the screw have to sit flush? I would use Redheads expansive bolts. is the steel plate use to hold up lots of weight?

[A930Rocket]

Redheads used here or threaded rod epoxyed in. Clean the hole very well before using epoxy or the dust will prevent adhesion.

And I would say 5/8" - 3/4" redheads/threaded rods within 12" of the ends of any bottom plates and 24" spacing.

Of course, once the bottom plate is secure, what are your plans to keep the rest of the house there? We are required to secure the house from the footer to the ridge. No point in fastening the bottom plate down if everything else isn't secured.

[look 171]

He did say no heavy stuff, so I am unclear as to what his needs are. 3/4" might be over kill. Simpson epoxy with threaded rod will stay for sure.