Expert: Dan Griffin - 1/25/2008

Question
QUESTION: I am about to buy a basic Ramset gun... I'm looking at the inexpensive one on Amazon for about 25 bucks... it's the kind you hit with a hammer.  Since I'm not familiar with this tool, I have a few questions.  I will need to use this for securing some bracing for new framing to an existing concrete slab.  Down the line, I will secure sleepers on to this same existing slab.  Question:  Regarding the length of the nail, how much of the nail needs to be imbedded in the concrete for a secure connection?  There seems to be 2 kinds of nails -- one with or without a washer.  Other than spreading the connection over a wider area with a washer, is there some specific reason I would buy nails with washers? It's my understanding that once a nail is embedded, there is  no way to extract it.  To remove the bracing, I would have to split the wood and use a grinder to remove the nail until it is flush with the concrete.  Correct?  Thanks so much for your advice.  

Paul Myers

ANSWER: Paul,

I have no experience with the hammer actuated PATs (powder actuated tools).  PATs are great tools for base plates, etc on concrete floors, they are also great for shooting lumber and metal studs onto steel.  There are no set answers for using them.  There is a range of pins and loads to shoot into various substrates.  If you know you are only shooting down 2x material, get 2 1/2" pins.  Try a green load (lightest), if it is not burying the head, try a yellow or red load.  You want to find the load that will drive the nail the proper depth in one shot.  The professional directions are to not re-shoot a nail, though it is certainly done every day (I am NOT telling you that you can re-shoot nails that didn't set right).  You will probably be just fine without the washers.  They are there to provide additional pull out strength to the connection.  You can remove gun nails if you have a big enough crow bar, it will probably remove a cone of concrete about 3" in diameter and 2" deep.

There are several reasons to consider an alternate method.  You do not have much long term use for the pins and loads.  Sometimes when you shoot into old concrete, the nail will blow out a chunk of concrete or not get a good bite in the concrete.  Changing your mind is problematic.  Sometimes the nail will shatter the board that you are shooting.

You might be better served to consider two other methods: One is to use something like Tapcons.  They will require a hammer drill and an impact grade screw gun, either electric or battery.  The impact guns are the greatest thing since sliced bread, but they are expensive.  You can drive Tapcons with a regular screw gun, but you will strip out more fasteners.  Do NOT install Tapcons deeper than 1 to 1 1/2 " deep or you will break as many as you get in.

The method that I would suggest would be to buy the Tapcon drill bits.  YOu need a hammer drill, the only hammer drills I own run SDS style bits.  Place the 2x, drill through the 2x into the concrete about 2", drop in a piece of #12 electrical wire with the insulation on, and drive a 16d common nail or double head into the hole.  You will need at least a 3' crowbar to pull the nail out if you change your mind.  You can probably use 16d box nails, they might require 2 strips of wire.  You can use solder or tie wire instead of the electrical wire.  You can use deck screws instead of the nails if you have a way to drive them.  You  should test the first on you do by trying to pull it out -  you'll know right away whether you have a hold of it.  With experience you can tell as you drive the fastener.  FAST, CHEAP, EASY - stuff we always have along.  Great holding power.  We keep the PAT for shooting down metal stud base plates into concrete and steel.  It is only faster for us because we have 10 round clips - for you, no faster.


---------- FOLLOW-UP ----------

QUESTION: Thank you for your prompt and very complete answer!  I may need the Ramset for other things as well... the thing that I worry about it that it will blow apart the existing slab which is very old.  I may try the copper wire/nail method if I see that happening.  Tapcons are a good idea also.  I have an impact driver and a Bosch rotory hammer (spline) and I suppose I could invest in the proper bit and the tapcons... but something tells me that would be more expensive than the Ramset.  Question -- can you remove tapcons or is that in there for good?  Thank you again... I'm sure I'll be back with more questions as this project progresses.  

Paul Myers

Answer
Pins and loads run between 50 cents and a dollar a round, depending on how many you buy.  Tapcons run cheaper, but about the same - again depending on quantities.

Nails and wire are cheap even though copper has gone through the roof.

I think that Home Depot rents out a powder actuated gun.  YOu could try before you buy.  On a commercial job site, PATs require an operator's license which pretty much says all the don'ts, so maybe they can't rent one out.

Tapcons can be screwed back out.  With an impact, they will probably come out quite re-usable.  With a regular phillips drive, the slots will probably be too torn up to re use.  The hex drive tapcons seem like a more positive drive.