While removing guled down finished wood floor several section of the first layer of the plywood subfloor has pealed up.

The black mastic used to glue to the wood floor to the subfloor is black and very hard but when sanded agressively it doe not break down except where a lot of heat then becomes very gummy wilth no smell.  Any clue on how to remove the majority of the 1/4" v notched trowel marks?  Also given the amoun of damage to the top layer of the plywood I am considering removing it then glue and screw 3/8 plywood down covering old joints and only screwing in at joists.  The glue would be construction aheasive but is that good enough?  OR do I spread a layer of yellow glue then screw that down?  The damaged area is large and is the entierty of the hallway and the dining room.

If there is another self done method please share your ideas?  The fact that someone lost their mind and glued to the subfloor directly without laying down some underlayment is anohter issue.

 

What will you put down for the new floor?  That might be a factor in how you treat the existing situation.  For instance, if you're planning on tile, then 1/4" hardibacker or durock cement board would be the choice.

Jim

1 minute ago, JimM said:

What will you put down for the new floor?  That might be a factor in how you treat the existing situation.  For instance, if you're planning on tile, then 1/4" hardibacker or durock cement board would be the choice.

Jim

Thanks Jim I am going to be putting down Luxury Vinyl Planks.  That requrie a flat and smooth sub floor with very limited imperfections.

Maybe there is a rental place that has a powered floor scraper

Just a bit of brainstorming here...   If you can heat it with no resulting fumes, would it be softened long enough to get some 1/4" underlayment down without any bumps?   Or soften it enough to trowel it relatively smooth?

Heat is an option and wd40 may be a solvent.  If I heat it up I would flattten is enogh to be sanded.  

Buy I would scrape as murch off as possible.

Or and thoughts on removing vs. fixing the floor?

Upon reviewing the scale of the repair it has been determined that it would be better to replace the sub floor.

Thanks again for all your thoughts and cares.

 

Replacing the sub floor is some what striaght forward.  Any walls parallel to the joists insert another joist at the part line of the existing and replacement sub floor.    Where the floor lay perpendicular to the joists insert solid blocking again to join the old and new.  The new will be glued and screwed where the old is nailed and squeeeky.  However I beg to differ.  From the outside of the bottom plate stay 1.5" away and use the old floor.  Stress goes on 45deg and the old that line should not go thru the joint of the old and new.  

I am also wondering why i need full depth joists just to support a sub floor?  As long as I give it something rigid to bond both new and old I thinK the sub floor will act as one and then maybe a 2x4 under the joint line?

What do you think?

 

OH the solvent side 3 things are solvent for that black glue/mastic.

Turpentine slower and cheaper the acetone.

Acetone fast but does not penerate more than turpentine.

WD40 does eventually break it down but not has good nor as fast as turpentine.

 

I think the 2x4 would be more than adequate for what you want to accomplish. I've been following this, and thought replacement was the best choice regarding the original sub floor.....despite being a headache, and expensive, I would guess.

A couple other things to look at before going to town on it.  What will the LVP be meeting at the ends of the hall, or other rooms?  It would be good to get the LVP close to the same finished height.  Have the other rooms already had the flooring redone, or are there plans to do so?  Is there a subfloor and underlayment layers under the existing wood floor that you are pulling up?  Is it 3/4" plywood?

I have worked with both of the newer 3/4" T&G OSB subfloor materials.  One is Norboard, the other Advantech.  The Advantech is a bit more expensive, but hands down the better product.  No way on a remodel that I would use Norboard again.

Regardless of whether you end up needing two layers, subfloor and underlayment, coming in with additional blocking "may" be a bit of overkill.  Consider that anywhere else in the house where there is a seam in the subfloor it is not standard practice to have blocking underneath the seam - whether or not it was a T&G material being used.  And too, especially in a hall, the inclination is to walk in the center - not 2" from the wall.

 

Also, when considering the finished height of the LVP, be sure to add in any type of vapor barrier/underlayment that you might use under it.

Edited October 17, 20214 yr by Cal