View Full Version : Wooden repairs, not boat.

04-10-2003, 03:45 PM
I think I know what to do, but ....

One of our joists has cracked. Some time ago, before we purchased this house, someone installed cabling for TV, phone, ... and drilled a bunch of holes in the joists. Some of these holes were located too close to the edge, and now one of the joists has cracked (and a couple of others are probably in some kind of "danger" situation, less than two inches of un-drilled joist.)

So I'm going to sister 2x10 into the floor, beside the joist, glueing, then hoisting the lot up with a floor jack, then nailing.

And then drilling proper holes to re-run the TV, phone, ... (thankfully no heating ductwork needs to be redone.)

Anyone else had to do this? Any hints? Cautions?

High C
04-10-2003, 03:53 PM
I think you're on the right track. Just be sure to get the sister lined up properly beside the old joist, pronounced "jerst" in New Orleans, using clamps and a jack to get it into place as necessary, then I'd use screws to attach it so as not to upset the alignment with hammering.

The structural demands of what you're trying to accomplish are not great, so I'd skip the glue or giant bolts or whatever. You're only trying to replace a small bit of lost strength.

Good luck!

Alan D. Hyde
04-10-2003, 03:55 PM
I assume you'll hoist before the glue dries? :D

If it's been that way for a long time, you might just bolt the middle of the sister (use big washers), then jack bit-by-bit over a long period to let the wood floors and adjacent joists bend back slowly to where they should be.

Then glue and nail when done.


J. Dillon
04-10-2003, 04:00 PM
JT is right on but like you mentioned I'd add the glue just for further peace of mind. ;)


High C
04-10-2003, 04:02 PM
Originally posted by J. Dillon:
JT is right on but like you mentioned I'd add the glue just for further peace of mind. ;)

JDUh oh, should I have used glue on my plywood boat?

Just kidding...

Bruce Hooke
04-10-2003, 05:50 PM
Another approach that could save you the trouble of disconnecting all the various cables is to bolt steel angle iron onto the bottom edges of the joist. We used this approach on a remodel job where the owner had notched out the bottom of the joists(!) so that he could push the water pipes up, so that he could have more ceiling clearance in the basement. Of course we had an engineer spec the size and bolt pattern for the angle iron...

04-10-2003, 10:06 PM
This steel angle on the bottom is an interesting idea. It could save a LOT of work (taking down the suspended ceiling & all of that wiring.) I'm going to ask a couple of better engineers than I about doing it this way.


04-10-2003, 10:19 PM
Well.... If you want to do it the complicated way....sure.... BUT.... You could also just sister on 2 pieces of 3/4" ply on either side of your weak joist. Jack it up first, squeeze a little 5200 on the surfaces, and bolt the damned sandwich together... Simple...See?