Pulling up glued and nailed sub-floor

[MarvinWatkins]

We are in the planning stages of an attic renovation. We want to turn it into a Master Bedroom Suite. The designer came in and had a look at the ceiling/floor joists to see if they would do for finished space. As you could guess, they don't.

So I am going to have to pull up the sub-floor and put in 2x12 floor joist. No problem putting in the new floor joists and putting on the new sub-flooring. Unfortunately, the old sub-floor is GLUED and nailed to the existing joists.:no:

I figured I would be taking a crow-bar and maybe a circular saw to get it up. I like working smarter, not harder, so does anyone have an suggestions on a smarter way to get the sub-floor off?

 

[Bas]

Ugh. Wonderful project.

I'd first cut out the subfloor between the joists. To get the remaining subfloor strip off the joists, you could hold the circular saw vertically and cut at the glue line. The tricky point being holding the saw vertically. It might be easier to use a multi tool with a woodcutting blade. Cut in from both sides to avoid too much heat buildup. You may need a power planer to smooth the joists if they used construction adhesive instead of regular glue.

 

[scsmith42]

Lots of ways to do this. I think that I would cut out some pieces of the subfloor near the existing joists, so that you can measure over to the exact edge of the joist. Then set up a straight edge for your circular saw to follow and trim the boards out in one shot.

 

[Canuck]

Sounds to me like Bas and Scott's suggestion would work fairly well.

Best to do the work while things are cool up there in the attic.

The 1st thing that I think I would check would be any wiring running between the joists. You don't need another hassle with the flooring work!

Wayne

 

[MarvinWatkins]

Thanks guys. Sounds like I will end up with a bunch of 14 1/2" strips of plywood.

Unfortunately, I am pretty sure they used construction adhesive.

Fortunately, the new 2x12 joist that are going in will a little taller than the existing joists. I will likely sister the old ones to the new ones and not give it another thought.

 

[RayH]

Marvin, You type faster than I do.
Forget the below:


Most likely I don't understand the situation, but why are you cutting out so much stuff? Looks like Bas' approach to cutting the flooring back to the joists then laying in the new 2 x 12s along side the old (smaller?) joists would be easier. Is there ceiling under the existing joists? How will you deal with that if you pull the existing joists? Is there a problem leaving the existing joists in place?

Like I said, most likely I don't understand the situation.:dontknow:

Best of luck on your project,
Ray

 

[MarvinWatkins]

The old joists will stay in place because the 1st floor ceiling is attached to them. I am just getting the sub-flooring off so I can get the new 2x12 joists in place beside (possibly sistered, i.e. nailed to the old joists) the existing ones. Unfortunately, the difference in the old and new joists is less than 3/4". That would make it too easy.

There is a long story regarding the existing joists that I won't go into.

 

[thsb]

I agree with the other suggestions but also would not be too worried about messing up the ceiling below. it would be nice to leave it intact but i imagine you will be patching and repainting the ceiling anyway so if there is a big advantage to pulling some of it down i wouldn't hesitate too much.

 

[DaveD]

You might want to consider not sistering new to old and just run the new ones in between the old ones. Maybe even on 12" centers. The more you bang on and disturb the existing joists the more chance to get screw/nail pops on the ceiling below.

Since the existing joists are close to 2x12s they are probably spanning a pretty good distance to be that big. Don't skimp on the spacing for the new ones. Particularly if you are going to have a big tub and/or tile floor. Tile floors typically want less deflection than vinyl or carpet covered floors. They also impart a higher dead load.

Lastly don't let the plumber butcher up the structural integrity of the new joists. Some of those guys seem to hate floor joists with a passion.

 

[walnutjerry]

The old joists will stay in place because the 1st floor ceiling is attached to them. I am just getting the sub-flooring off so I can get the new 2x12 joists in place beside (possibly sistered, i.e. nailed to the old joists) the existing ones. Unfortunately, the difference in the old and new joists is less than 3/4". That would make it too easy.

There is a long story regarding the existing joists that I won't go into.

Just block the new joist up By placing a 1" block (or whatever it takes to get above the old floor level) under each end of the new joist, then there is no reason to remove what is on top the old joist.

Jerry

 

[Skymaster]

Egzachery; at the top plates cut a pocket thru subfloor measure over to joist face both ends, snap chalk line, run a circ saw and cut out sub; Then sister as you want dont even mess with the 1 1/2 pc glued to old joist. Construction adhesive and SCREW,REPEAT SCREW, did I say SCREW the new joists in place.NO HAMMERS ALLOWED. NOTE CROWN REPEAT CROWN the new rafters before u place them! Also shoot a level line PLATE to PLATE Do NOT rely on existing floor to be level. do this at both sides, once you establish a level line at the 4 corners,pull strings tight between corners of each top plate, set new joists to the STRINGS. This will get you the most flat and level floor.

In fact nudder thought; once you run the circ saw and chop old sub out you can actually grab a router with a flush trim bit and run the edges nice and flush real quik and ez. 1/2" router and 1/2" trim bit be nice.
Ok third important point set the depth of your saw ONLY deep enuf to just cut thru sub flooring! You need to hunt electrical wiring with you saw . if u have or can borrow a sawzall is great to get the starting pockets done at the plates,SHALLOW cutz

 

[merrill77]

If you need to get the nailed and glued leftover floor sections off the joists after removing most of it from above, then a reciprocating saw (sawzall) would be a good option. But if you can just leave it, it could save you a good bit of work.

 

[Jeff]

I'm curious and puzzled about the engineering of your new project.

It sounds like a structural load issue. What are the dimensions and spans of your existing ceiling/floor joists (2 x 8 x ?, 2 x 10 x ?)? While they're adequate and up to code for attic space they may not have sufficient load bearing capacity for a living area as planned. Is that correct?

What does your Orange county code require and will you have to pull a permit for the work? That's not a bad thing and you will likely get some good advice from the inspectors on what is required and how it should be done for proper load management. Specifically, how will the new 2 x 12s tie in to the existing structure at each end near the roof line? I'd want to be clear and safe on this point rather than just "sistering in" a new joist to the existing structure across that span. :dontknow: Perhaps the old and new joists should be bolted together instead of nailing or screwing (not lag bolts, but through bolts and nuts/washers with a steel plate). Maybe overkill, but you'll only get one chance to get it right IMHO.

Lastly, you may want to consider shelling out extra $ to have the work done by someone who is licensed, bonded, and insured. That protects your investment in your total home!

 

[MarvinWatkins]

We are having this work designed and engineered by licensed professionals. The work will be permitted and up to code.

I plan to check into how the originals are to be tied into the existing structure.

 

[MarvinWatkins]

Thanks all for your input. I will try to let you all know how this project goes, however this will be over the next year. So, don't look for updates tomorrow. I do have a day job.

 

[MarvinWatkins]

Closing thread.

I had actually forgot I still had this out here.

Thanks again.