On Jan 3, 2:22*pm, RicodJour wrote:
On Jan 3, 1:07*pm, DerbyDad03 wrote:



On Jan 2, 11:28*am, RicodJour wrote:

I still use the term 'lag', also, when the state of the art has passed
them by. *Nowadays there would be very few situations where I'd reach
for a lag (and the drill to bore a pilot), instead of using self-
drilling structural screws that can be driven with an impact in a
couple of seconds.

In the OP's situation I'd rather have more smaller fasteners that were
easier to install, than a few larger ones that were more onerous. *In
the day sisters were simply nailed and they held just fine. *Now
everything is glued. *Either glue or structural screws would be fine
by themselves, but you need the clamping pressure of the screws if
you're going to glue, so...

Another thing about lags - their maximum diameter is restricted to 1/4
of the wood thickness that the business end is buried in - in this
case a 2x would allow a 3/8" lag. *Lags are notoriously crappy metal,
made in places where lag guilds never took off, and their load
capacity is not all that much greater than other choices such as
common nails and structural screws, which are easier to install.

There's really not a lot of load on a typical floor joist. *Figure a
12' span and 16" OC with a 40# live load, and that's about 640# total
for the full span. *A 10d common nail can take about 70# in shear, so
we're not talking about a lot of load, fasteners or concern.
Particularly since the OP's joist has been like that for decades.

One caveat - make it pretty. *Even if the repair is a straightforward
one and not structurally critical, a sketchy looking repair will raise
more flags when the house is sold. *So make it a neat, workmanlike
job.

Wouldn't lag screws be "gentler" on the tile floor above than either a
hammer or an impact wrench?

Depends on the tool and fastener. *A nail gun would be preferable to a
28 oz framing hammer in a dyslexic's hands, and an impact driver (not
wrench) driving a 2' or 3" screw would kick up about as much of a
problem as a fatass dog waddling around upstairs.

Drilling with a standard drill and using a rachet to drive the lags
wouldn't subject the grout or tile to any excessive vibration.

True, enough, just slow, and lags are problematic when they're
shallowly embedded. *Lag bolts have seen their day. *They had a good
run - let them pass in peace and don't make them linger.

R

"an impact driver driving a 2' or 3" screw"

I'm thinking that maybe a 2 foot screw would be a bit excessive for
this particular repair. ;-)