Replacing subfloor

Shop deals on ebay
SpartanEpoxies
Advertise with us
House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Thanks for the suggestions. What would be the best bet for raising the 2 walls that run parallel to the joists? I was thinking about putting in 9'' tall 4x6 posts on the stem wall every 12''to support that wall or blocking underneath that wall to support it when I do the subfloor. It is more then likely going to be rotten whatever is currently their. Their may not be a sill plate their either. I think that those 2 walls will be the hardest part of the job. The interior walls I can attempt to put another joist under or just block them. I just don't know how much room I will have between the last joists that runs next to the stem wall and the space where the sill/rim joist should be.
 
Explain what you think a stem wall is.
It is not a term we use up here but I have heard a few different meanings.

Footing with wood wall below floor
footing and concrete wall below floor
footing concrete wall and wood would wall below floor.
Footing and piers below beams.

100 year old house most times the floor joist are just nailed and hung from the wall studs as they were balloon framed rather than platform framed as we see today.
So you might be looking at a mix of old and new systems.
 
I was just referring to the concrete foundation. The gap between the top of the concrete and the bottom of the old subfloor is the area I was referring to when I said I wanted to block it or put in some kind of 4x6 that is the same height as the gap to support it.
 
BrandonBoss said:
I was just referring to the concrete foundation. The gap between the top of the concrete and the bottom of the old subfloor is the area I was referring to when I said I wanted to block it or put in some kind of 4x6 that is the same height as the gap to support it.
Click to expand...

Yes you can do that even with short pieces but then you have to figure how to join the new floor sheeting.
 
If I am able to block it that should work to hold up the new sheeting between the wall and the nearest joist. I plan on cutting the subfloor flush with the wall so I can install the larger 1'' subfloor. I will try to make sure to have a block underneath the joints of the subfloor too. Any tips on jacking up the outer walls in case I have to?
 
In an effort to make us all stop & think for a second, is it possible that correcting the issues with the joists will prevent the need to do major surgery on the subfloor?:confused:

Side question: Is a 2x10 with a 1.5 inch notch any stronger than a 2x8 when it comes to joists?
 
slownsteady said:
In an effort to make us all stop & think for a second, is it possible that correcting the issues with the joists will prevent the need to do major surgery on the subfloor?:confused:

Side question: Is a 2x10 with a 1.5 inch notch any stronger than a 2x8 when it comes to joists?
Click to expand...

I think it depends on who you talk to.
The notch gives the timber a place to break or start to crack, but sistered to the smaller joist will aid with the bend or sag.
So really the same advantage should be obtainable with the sister cut short of the bearing walls.
 
The notch was to be level with the previous joists. 2x8's were a little to short so they used 2x10's and notched them enough to be level with where the house was before. It wasn't to provide extra strength.
 
I don't want to do this major surgery but at the same time when I am done with this fix I don't want to mess with it again ever while living here. I plan on ripping up the carpet, hardwoods, and underlayment to expose the subfloor first and see if it is salvageable. If it looks decent I will probably go underneath the house with one of the guys I use for construction work and clamp the two joists together and use a palm nailer on them. I may use bolts on them as well. The other thing though is underneath areas like kitchen cabinets / bathtub how would I connect the subfloor to the newer joists? Would I just try to toe nail some nails through the new joist into the old subfloor from the bottom? Or use screws?
 
When you install the new joist use a lot of floor glue between the joists and on the top edge of the new one.
Your first nails want to be sucker nails. Nailed near the bottom edge of the new joist on a 45*, once nailed all the way in, a few heavy swings with the hammer will suck the new joist up against the floor.
After that then nail 3 nails every 16"
 
I don't plan on installing new joists though because they were all replaced 6 years ago with pressure treated ones that were sistered to the old joists. So would I just try to get glue on the top of the joists that are already their and then try to send in screws at a 45 degree angle to suck the subfloor down onto them? I appreciate you taking the time and walking me through all this.
 
45* screws will not pull a gap closed, actually it will lock the gap in place.

Better would be to pre drill a 2x2 in two direction apply glue to top and side, screw it to the top of the joist first and the screw it to the floor. Pre drilling is important so the threads don't grab the 2x2 . Both screws straight in and straight up.
 
So I was planning on screwing down the 1x6 planks to the new joists. Will that not pull the joists and 1x6 together?
 
One more set of questions that I am wondering about. Which kind of screws/nails do you think I should use for connecting the old subfloor to the new joists and what kind of glue or adhesive do I use for the sistered joists that I plan on clamping together and screwing together? I was going to use the subfloor adhesive for on top of the 1x6's under the new layer of plywood. Wanting to know what kind to use for those 2x2's you recommended and also what to use in between the sistered joists that I am going to try to clamp together. Thanks again.
 
A few items to consider:
Hangers....use that palm nailer to drive the nails or you can also use screws.
Glue.....Any construction adhesive sold for sub-floors, roof decking, etc. will work. Both for use between the 2 joists or for the new sub floor.
Flooring......3/4" tongue & groove plywood is sufficient as a sub-floor.
Fasteners......screws are less likely to "squeak" later on. Nails loosen and that causes the noise when the board moves against the loose nail.
Screws........The coated exterior screws will work in PT lumber as well as galvanized screws.
You could also look into the Timberlock screws for use in pulling the 2 joists together. They have a hex washer head and will not pull through the wood as easy.
Planing/leveling......do not try and make everything perfectly "level". Just get the bumps and dips out of the joists and live with a minor slope if necessary.

If you pull the entire sub floor up, it will be much easier working on the joists. You can also do it in sections. And for the parallel wall, you could add a joist to catch the new flooring along that edge.
 
You must log in or register to reply here.

Latest posts

Back
Top