Wood Screws/Lag Screws reusage in same hole

[adelz]

Hi.

I am wondering if there is a clause forbidding screwing more than once in a same hole with wood screws or lag screws. My feeling is that it will weaken the connection, but I can't find anything in the Canadian Standard CSA O86. Maybe in the American Standard?

 

[Deker]

As long as the hole isn’t stripped or oversized and you start the screw by hand to make sure it follows the original threads, I don’t see an issue with reusing the holes.

 

[MotorCity]

I am not aware of a code provision that prohibits this, and in general I think it would be ok as long as a replacement fastener of similar diameter and thread size as the original fastener was used. However, my concern would be that there could be distortion of the hole that is not visible due to a prior load. For example, if the original fastener was in shear or bearing and deformed the hole, such a deformation may not be immediately apparent to the naked eye. To mitigate this concern, maybe you could require that the replacement fastener be 1/16" larger in diameter than the original.

 

[phamENG]

For light duty applications, I wouldn't worry about it too much so long as you're going back with an identical fastener. Since you already have threads and don't need to tap new ones, you have to be careful that the existing threads are reused. Similar to machine bolts in tapped holes in metal, turn it counter clockwise a few turns until you feel the threads drop in and engage to prevent 'cross threading' and stripping out the hole.

If it's overhead or holding up a heavy shelf, maybe coat the lag with some epoxy before you put it back in.

For real structural applications, no. I wouldn't try it. Go a size larger, replace the piece, or reposition the connection (ledgers, etc.).

 

[NorthCivil]

What are your diameters?

lag screws are usually significantly bigger than wood screws. wood screws typically you just drive in with no pre-drilling, lag screws need some pre-drilling.

so if you withdraw the wood screw, drill the hole to accomodate the lag screw, then apply the lag screw, i see no issue.