Installing a new sub floor
#21
(07-30-2018, 04:04 PM)DogwoodTales Wrote: I have 2x10 joists at 16 oc with about 11ft of span.
Looks like my house is a little better than the recommended in that regard.

Sounds like a quality build.  

They probably used nails back then.  You might throw a bunch of screws in the existing subfloor and then check for squeaks.   That would be fast and easy.  Construction screws, not drywall screws.  

If that does not work then new subfloors sound like they are on the menu.


Note:   I think they use construction adhesive + nails nowadays.
No animals were injured or killed in the production of this post.
Reply
#22
I would first recommend removing some of the metal cross bracing straps in areas where you notice a squeak and replace it with solid wood blocking where possible. This is a common issue with the metal cross strapping and I have had to do the above in a couple homes, including my parents. The metal straps flex and do not create a rigid diaphragm to allow the joists to act as one solid slab.

I would at least try this before removing all of the subfloor and installing new. It may not help, but I think it will. Also try to screw down the existing boards in areas of squeaking. If that works then screw it all down. Cheaper and less labor than replacing. The nail holes elongate and work free over time.
Reply
#23
You got it covered.

Did anyone mention T&G plywood?
Reply
#24
IDK - since I'm going to have full access to the kitchen floor and the rest of the family will be out of town that week and my kitchen area is only like 9x12 and therefore I don't need many sheets ... I think I'll just tear it up and replace it (ounce of prevention ...). I was thinking of using t&g plywood and not osb.

I know about using the sub floor adhesive, but should I use that in the t&g as well as on the joists? Seems like it would only benefit. Is there a particular adhesive that's better suited for this, or does that not really matter?
Should I use some paper of some sort, like roofing paper? Maybe between the sub floor and the under lament floor?

Good ideas on the cross bracing. From what I've observed from underneath while people are walking above it doesn't seem to be limited to just where there is metal cross bracing, so maybe it's more just a function of old nails and ship laps rubbing.

Thanks for the feedback to all.
Ray
Reply
#25
Just went through this on my bathroom remodel.

Loctite PL400 is specifically made adhesive for subfloors. Gluing the tongues doesn't hurt. Nails or screws 12" OC in the field, 6" along the edges. If tiling, I'd use screws (construction or deck). You need a 1/8" gap on the panel ends where fastened to the joist.

Lots of good info here: Subfloors
Reply
#26
(08-02-2018, 06:38 AM)DogwoodTales Wrote: IDK - since I'm going to have full access to the kitchen floor and the  rest of the family will be out of town that week and my kitchen area is only like 9x12 and therefore I don't need many sheets ... I think I'll just tear it up and replace it (ounce of prevention ...). I was thinking of using t&g plywood and not osb.

I know about using the sub floor adhesive, but should I use that in the t&g as well as on the joists? Seems like it would only benefit.  Is there a particular adhesive that's better suited for this, or does that not really matter?
Should I use some paper of some sort, like roofing paper? Maybe between the sub floor and the under lament floor?

Good ideas on the cross bracing. From what I've observed from underneath while people are walking above it doesn't seem to be limited to just where there is metal cross bracing, so maybe it's more just a function of old nails and ship laps rubbing.

Thanks for the feedback to all.
I was always told that the cross bracing was designed to keep the joists vertical.  If they become tilted the load carrying ability is compromised.  I don't know how the cross bracing would affect squeaks.  But if it is absent it is a good idea to install it. 

There are a number of brackets designed to  eliminate squeaks but they all assume that you don't have topside access.  If the old subfloor does not have any rot, I can't see why you can't simply go over the old one with a new one.

There are quite a few discussions on this subject.  Apparently there are pluses and minuses to the idea:  https://www.google.com/search?q=adding+s...e&ie=UTF-8
No animals were injured or killed in the production of this post.
Reply
#27
So I took a look at the metal cross bracing last night.
First thing I noticed is that there doesn't seem to be a whole lot of it. I don't know how many there should be in a given length of a floor joist, but this has maybe one or two in the 11-12'  length. 

I pulled and pushed on the metal strapping and could hear the floor itself squeak above much like it sounds like above with 200 lbs walking on it.
I don't think I heard any squeak or rubbing from the strapping itself.
Also at least some of the metal cross bracing seems like it could use more tension, but I'm obviously no expert on the subject.

I'm still inclined to go the extra mile and replace the sub floor. That way I know it's glued down and I've done everything I could to eliminate the terrible squeaking noise.
I think I need to shore up the cross bracing as well.

What would  be the best way to go about that if I take up the sub floor and have top and bottom access?
The floor joists are 2x10s spanned about 11 ft.
Just use 2x10 cross bracing cut to fit and screwed in place on both sides?
How frequent? (spacing between the cross braces) and Distance from the ends?
I suppose more frequent is better than less, but I don't want to go way overboard on it either.

I've also noticed that while the sub floor is made up of 3/4" thick planks, which I think are ship lapped, there's also a 1/2 - 5/8" plywood on top of that.
Perhaps at least some of the squeak is being produced by those two layers rubbing on each other?

Thanks for your help guys.
Ray
Reply
#28
I just looked at my joists in the basement.  They are all 3" x 8" and no bracing at all.  I don't know what to make of that.  No squeaks though.
No animals were injured or killed in the production of this post.
Reply
#29
3x? Wow
Is it oak as well?

Is osb recommended instead of plywood for any particular structural reasons?
Ray
Reply
#30
(08-08-2018, 02:20 PM)DogwoodTales Wrote: 3x? Wow
Is it oak as well?

Is osb recommended instead of plywood for any particular structural reasons?

I think the reason was that it was originally the builder's own home.  It also has plaster walls and all the other houses in area that he built have sheetrock.  

I drilled a couple of holes in one and it smelled like Douglas Fir, but it is way harder than any Douglas Fir I have ever come across.  Hammering in nails is a Herculean chore.

I'm sure it is not oak.  I'm not 100% sure it is Douglas Fir.  

As to the structural reasons, I have no idea.  (But the floors don't squeak.)

This article in the Bob Vila site seems to say that OSB is preferred:  https://www.bobvila.com/articles/526-enh...-products/
No animals were injured or killed in the production of this post.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.