How do you extract and replace bolts going into concrete?

Question

I am replacing a deck and I need to pull out some of the bolts that attached the old ledger board to the house. What is the proper way to do this without damaging the concrete too much?

Answer 1

Wow, done all of those ways (previous Answerers) and I think I found an easier way, guys.  This is after about  200 bolt "extractions", different jobs, over 2 or 3 years...

Try this...

Tools required:   1) A hammer,  with 3 - 4 lb head.

This can be a 3 or 4 lb sledge (long handle) or, my preference, a 12 - 14 inch (short handle) which allows you, actually, less work.   : >  .

Beat the bolt sideways, 3 to5 whacks at a time, then, same thing the other way.  The more you whack it, the weaker it gets, just keep going and it will pop right off!  90% of the time, level or below surface!

I found that a bolt of about 2 or 3 inches long is the easiest to handle.  If it's longer, you can use a pipe for leverage to bend it over and beat it  (now, now, time for that later ; >) or cut it  down to 3"with a big bolt cutter.

I found I could "whack" 4 bolts faster than grinding just one.

Side benefit here:"Whack" 20+ at a time, you will have forearms as good as Popeye!  Spinach or not!

Hope this helps...anyone.

Rong

Answer 2

if the bolts are hammered in, dont try to remove them!!! anchor bolts are designed to wedge themselves tighter as they are pulled out, thus giving the ability to tighten a nut without pulling out the bolt.advice: if the bolt threads arent too damaged, try to repair the bolt with a thread die of the correct size and thread taper,found in tap and die sets or as a single tool at most home improvement centers.worst case:if the threads are too far gone, i recomend cuting it off and seting a new anchor.firstly,determin the size bolt needed,purchase new ones at any home improvement center, then use a hammer drill with the corresponding size masonery drill bit to make a new hole a few inches from the old one,at the correct depth(hammer drills can be rented for a minimal cost)next,start a nut on the new bolt(about 3/4of the nut)this prevents damaging the threads, then carefully hammer the new bolt into the new hole.be sure to clean the hole of dust and debris first to prevent slippage.remember,when these anchor bolts are set, they will NEVER come out!!!! i sugest getting bolts that are several inches too long, then cuting off the excess after your ledger board has been attached.i hope this helps, and happy building!!

Answer 3

Cut them off flush with a sawsall or a hack saw if you don't have a sawsall. You also can use a small grinder with a fiber cut off wheel. Don't forget to use safety glasses.

  Then you can drill out the bolts and use special anchors to complete the job. A  lead one is called an ackerman. At a building supply store they can recommend what you need.

Answer 4

You won't damage the concrete, I'm sure the bolts go into a set-in anchor.   Some of the bolts may go  into the sill, or thru the rim joist as well.