Sistering a Joist

After cutting away the floor, I had a hand from a worker of mine to sister a joist.  Four of the old joists had been cut away in large part by what I imagine was a very thoughtless plumber. 

Here's a look at the joists and floor underneath what used to be the 2nd floor bathroom.  Many years ago, a plumber cut away the top areas of these joists to make room for pipes.  Over time, there was also extensive water damage.  As such, these joists are weak and need to be jacked-up and sistered.  I've got a 2 1/2 ton floor jack and a 4x6 beam that I'll use for that purpose.

Here's another view. Note the white marks and notches in the joists.  I've already sistered several of them, and you can see the structural connectors that were used.

Here's a view from the other direction.

That electrical wire is in the way and needs to be moved tomorrow before I can sister that corresponding joist.

I had to notch the joist in 2 areas -- at the far end  next to the wall, and also to accept the original structural beam.

First we test-fitted the beam.  Next we took it down to apply construction adhesive.  Also, I used an angle grinder to cut away several nails that would have been in the way.

After ***MUCH***  pounding with a 3-lb hammer and 5-lb sledge hammer, we finally got the board into place.

The last step was to jack up the paired joists with the 2.5 ton floor jack, and then when it was level, to use structural connectors to affix the new joist to the old one.  Tomorrow I'll move the electrical wire and get this part of the job done.

Construction Update - Cutting Back 2nd Floor For Staircase Header

Hello everyone! Here's an update on construction at my house.  It's been a loooooong time and a cold winter, so quite a lot has changed since my last update of this sort.  Yesterday I worked on two significant tasks on the house.  The first was to cut back the second level floor and joists so that there is enough "run" or space to be able to construct building-code compliant stairs down to a new landing and exterior door.   The second project is to sister a number of cut-away joists that hold up the main second unit bathroom.  These joists are long... about 16 feet each, so inserting them and jacking them up is a bit tricky.  More on that in a second post.  For now, take a look at the work to prepare for building the staircase.

Here is a view of the area on the second floor that needs to be cut back.  If it's not cut back and I build the stairs, then the stairway will be too steep, and it will fail the building inspection.

Here's a view from the bottom.  Actually I have already cut away the new double header that I'd originally built.  This was added primarily to strengthen the structure at the bottom of the old staircase that leads up to the third floor.

Another angle.

Here are my initial measurements and cuts.  I used a laser on the bottom side to ensure that everything was straight and square, and drilled small pilot holes up through the floor (which is about 2.5" thick).  I used my circular saw to make the bulk of the cut.  I set the initial depth to be shallow, then increased the depth by ~1/2" until it was fully extended.  Next, I used my sawzall to cut the joists

 

The last cut was along the right side, and ... "voila!" the whole floor section dropped down the the first floor.

...like so!

Here's a closer look at the piece.

....and another.

Here's a close-up of the cut itself.

The view from the top-down.

The view from the opposite side.

Next, it's time to sister the joists that run underneath this floor.   Stay tuned for my next post.

Catching Up! Subfloor Progress

Here is the partially completed floor.  Take a close look at the original, 101 year old plank floor.  These planks are old-growth wood, which is incredibly strong and has shown great rot and mold resistance.  These planks are 7/8" thick. The old subfloor rests on joists that are spaced 18" apart.  I put in >5000 new ring shank nails to tighten this down in order to prepare for the installation of the new subfloor.  I chose to use Advantech 23/32" OSB.  It has an increased moisture and water resistance.  This is important since the basement is a "fieldstone basement" and is a wet basement.  This means that the basement is not (and will never be), water-tight.

Here is another view.  Note my tool room.  This has steadily filled up as I've gotten further into the renovation project.  The halogen light is for when I work at night.  Also note my shop-vac.  I've filled and emptied this several hundred times in the past 6 months.

Each sheet of OSB / Advantech is glued and screwed down.   As well, it is "tongue and groove", meaning that the edges of the sheets fit together like Lego, increasing the rigidity of the final floor.

Liquid Nails!  This is the glue I'm using to hold down the flooring.   After this, I lay down the sheet, then use a laser and pen to mark screw holes along the joists.  This has to be exact, or else the screws will not have anything to bite into and the floor will exhibit play / movement and will likely develop squeaks.

Several sheets further along.  Starting to look much nicer!

Here is a close up.  OSB joints are offset, which improves rigidity.  Note the screws.  Each one is aligned by laser, then hand-marked.  Next I pre-drill each hole.  Then I switch to an "impact driver" and drive in 3" composite deck screws one-by-one.  This floor is not going anywhere!

Each sheet is cut to line up with the new 2x6 framing.  I'm done about 80% of the first floor now, and will try to finish it early this week.  This will lay the right foundation to install my Noritz combi-boiler and baseboard hydronic heaters.  With the recent New England snowstorm, some heat in this house would be very welcome.  I'll take photos tomorrow and post them to show how much snow we've gotten... it looks like a lot!