Home>Discussions>YARD & GARDEN>Decks, Patios, & Porches>Deck repair question - removing lag bolts
9 posts / 0 new
Last post
twinsrus
Deck repair question - removing lag bolts

I have a deck that is sinking at one corner. My plan is to remove the lag bolts, jack the deck up up, then put in new lag bolts on opposite corners of the first set to stabilize the deck at the new height.

I can't get the lag bolts out that are there now. I backed them out about an inch - no farther. (They are lag bolts - smooth with threads at one end for a nut.) Suggestions?

dj1
Re: Deck repair question - removing lag bolts

One way to force the bolt out is to pound a same size bolt from the threaded end (after you remove the nut of course), then use a wrecking bar from the head side, to bring it out.

Still having problems? cut it off.

ed21
Re: Deck repair question - removing lag bolts

The weight of the deck may be stopping the bolt from coming out. Try jacking it up a little to relieve the pressure.

jkirk
Re: Deck repair question - removing lag bolts

sounds like either the hole was predrilled too big so the threads arent doing anything allowing it to back out or the rim board is rotting do to improper flashing of the deck ledger

A. Spruce
Re: Deck repair question - removing lag bolts
twinsrus wrote:

(They are lag bolts - smooth with threads at one end for a nut.) Suggestions?

Lag bolts have a very course thread on them that bites into the wood itself, they do not have huts.

Standard bolts have machined threads that accept a nut to provide the clamping force.

As suggested, use a bolt of similar size to drive out the one you're trying to remove. If you have a slide hammer, attach it to the head of the bolt and have at it.

Gizmo
Re: Deck repair question - removing lag bolts
A. Spruce wrote:

Lag bolts have a very course thread on them that bites into the wood itself, they do not have huts.

Standard bolts have machined threads that accept a nut to provide the clamping force.

As suggested, use a bolt of similar size to drive out the one you're trying to remove. If you have a slide hammer, attach it to the head of the bolt and have at it.

Spruce is right there machine or carriage bolts. Drive them out with another smaller diameter bolt. Your a hammer or pry bar behind the head adding pressure as you turn the bolt out.

dj1
Re: Deck repair question - removing lag bolts

Chances are that the bolt is bent. Bending bolts is an old trick to make them fit drilled holes which are not perfectly straight.

Still the answer to your problem will be to pound it out.

twinsrus
Re: Deck repair question - removing lag bolts

I appreciate all the answers I have gotten.

The couple of you suggesting I try and hammer them out - that would be nice, except they are almost inaccessible unless I tear off several rows of boards on top so I can have at it. Trying to avoid that. Lying on back back under the deck gets me no leverage.

Since I was going to jack the whole thing up anyway, I'll try that and see if I can get them out. Otherwise, I may resort to the final suggestion and just cut them.

I used the term lag bolts because a lag screw is something that screws in - no nut - at least that's what I thought they were.

If anyone else has a better idea, I'd love to hear tit.

Thanks again for your responses.

A. Spruce
Re: Deck repair question - removing lag bolts
twinsrus wrote:

I can't get the lag bolts out that are there now. I backed them out about an inch - no farther. (They are lag bolts - smooth with threads at one end for a nut.) Suggestions?

twinsrus wrote:

I appreciate all the answers I have gotten.

I used the term lag bolts because a lag screw is something that screws in - no nut - at least that's what I thought they were.

Well, you either got one or the other. If you've got nuts, no pun intended, then you've got a standard machined bolt. If you have a super course thread and no nut, then it's a lag bolt.

If there is no nut, then you've probably got lag bolts, so I would suggest trying to get a pry bar or drive some shims under the head to tension the threads, then try to back it out with a wrench, adding more pressure with the prybar/shims as you twist the bolt until it backs out on its own.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.