Some Questions On Flooring

[Motorman55]

Our house was built in the late 1970's over a crawlspace. There is insulation between the floor studs. We are remodeling this spare bedroom into a hobby/craft room. To this end I'm replacing the old carpet/padding with vinyl plank flooring. The old carpeting had been down since before 2006 at least.

I am using: 'Lifeproof' brand, ridgid core, underlayment attached; high traffic, 22mil, waterproof vinyl plank flooring. It does not require any further underlayment.

Upon picking it up I found the following type sub flooring material which looks like MDF to me. I posted some pics. It is tongue and groove which you can tell thru the gaps between the panels.

Questions:

1. Could this be the actual subfloor or just additional flooring added on top of a plywood subfloor to raise or use just for the installation of the carpeting?

2. Would this be a special type of treated MDF specifically used back in the 70's for underlayment?

Once I removed the carpeting/padding I could smell that old damp musty mildew odor. No oders were detectable when the carpet was down. In fact the carpet was very clean with no stains and no apparent water stains on its underside when I pulled it up.

There is evidence of some water or moisture staining along the two outside facing walls. I hooked up a dehumidifier and ran it for a couple days. All the panels are dry and flat with no signs of warping or raised areas even along the those walls.

Although I didn't see any signs of black mold I sprayed some Mold Armor Rapid Remidiation around the walls baseboard perimeter to make sure before I remove the baseboards themselves. Of course now I have that bleach smell, but thats dissapating. Yesterday I opened the windows and placed a fan in one of them to draw fresh air into and out of the room.

Question: Should I proceed with the flooring as is or.....

A. Should I fill the gaps between the panels? If filling the gaps, should I use siliconized caulk or wood putty or ?
C. Should I paint the floor with a sealer type paint like KILZ? Maybe their Mold and Mildew Primer?

Note: Before going any further I will be removing the baseboards at which time I'll check for moisture and if everything is basically dry I'll spray more of the Mold Armor Rapid Remediator followed up with Mold Armor Mildew Preventer/Disinfectant.

Any help or advice appreciated. Thanks in advance.

 

[Motorman55]

Our house was built in the late 1970's over a crawlspace. There is insulation between the floor studs. We are remodeling this spare bedroom into a hobby/craft room. To this end I'm replacing the old carpet/padding with vinyl plank flooring. The old carpeting had been down since before 2006 at least.

I am using: 'Lifeproof' brand, ridgid core, underlayment attached; high traffic, 22mil, waterproof vinyl plank flooring. It does not require any further underlayment.

Upon picking it up I found the following type sub flooring material which looks like MDF to me. I posted some pics. It is tongue and groove which you can tell thru the gaps between the panels.

Questions:

1. Could this be the actual subfloor or just additional flooring added on top of a plywood subfloor to raise or use just for the installation of the carpeting?

2. Would this be a special type of treated MDF specifically used back in the 70's for underlayment?

Once I removed the carpeting/padding I could smell that old damp musty mildew odor. No oders were detectable when the carpet was down. In fact the carpet was very clean with no stains and no apparent water stains on its underside when I pulled it up.

There is evidence of some water or moisture staining along the two outside facing walls. I hooked up a dehumidifier and ran it for a couple days. All the panels are dry and flat with no signs of warping or raised areas even along the those walls.

Although I didn't see any signs of black mold I sprayed some Mold Armor Rapid Remidiation around the walls baseboard perimeter to make sure before I remove the baseboards themselves. Of course now I have that bleach smell, but thats dissapating. Yesterday I opened the windows and placed a fan in one of them to draw fresh air into and out of the room.

Question: Should I proceed with the flooring as is or.....

A. Should I fill the gaps between the panels? If filling the gaps, should I use siliconized caulk or wood putty or ?
C. Should I paint the floor with a sealer type paint like KILZ? Maybe their Mold and Mildew Primer?

Note: Before going any further I will be removing the baseboards at which time I'll check for moisture and if everything is basically dry I'll spray more of the Mold Armor Rapid Remediator followed up with Mold Armor Mildew Preventer/Disinfectant.

Any help or advice appreciated. Thanks in advance. View attachment 2475997View attachment 2475995View attachment 2475992

bump

 

[steves_001]

Looks like old particle board underlayment. You could kilz it if worried about smell. Otherwise usually there is a 1/2 ply layer under it as the actual sub floor. Look in a floor register to confirm. If so and you are worried about it, pull the particle board out and replace it with t&g osb.

 

[bluedog225]

I have no particular expertise. Having said that, I shop vac the perimeter and any cracks. Then bleach the entire area. Maybe 5%. Then dry very thoroughly.

Kilz seems smart.

I like the life proof stuff.

 

[MoonRise]

That's not MDF.

MDF is basically compressed sawdust.

That looks more like particle board, which is compressed small 'chucks' of wood bigger than sawdust.

Pick up/out that broken triangular corner of the piece shown in pic #2 and look at it and compare to pictures or in person looking at some examples of MDF and particle board. Or post a good picture of the broken triangular piece including the 'side' grain so we can see it.

MDF is not water resistant and it swells and disintegrates badly.

Particle board also is typically NOT water resistant, but there are some special versions of particle board that are somewhat water resistant.

Evaluate the condition of your existing (particle board?) underlayment for damage, smoothness, stains and odors, and flatness. Proceed appropriately.

You may be able to see what the subfloor is and how thick your underlayment is when you remove the baseboards or the broken triangular piece of underlayment.

Buy an actual moisture meter to check for moisture. Pin units are typically a bit more accurate than pinless ones, but either can work 'ok'. You can check the underlayment, the baseboards, the drywall (Ha! Check the moisture in the drywall, get it? ), etc.

I'm not familiar with any tongue and groove particle board panels, all I've seen have been square edge. Doesn't mean that you DON'T have t&g particle board panels, just that I'm not familiar with any such panels. Particle board is not all that strong to begin with and cutting the thickness into thirds for the t&g would make it even weaker there.

And those gaps between panels don't look to good either.

I would NOT apply any water based things to either MDF or particle board, because they can both swell and be damaged by water or moisture.

 

[Motorman55]

That's not MDF.

MDF is basically compressed sawdust.

That looks more like particle board, which is compressed small 'chucks' of wood bigger than sawdust.

Pick up/out that broken triangular corner of the piece shown in pic #2 and look at it and compare to pictures or in person looking at some examples of MDF and particle board. Or post a good picture of the broken triangular piece including the 'side' grain so we can see it.

MDF is not water resistant and it swells and disintegrates badly.

Particle board also is typically NOT water resistant, but there are some special versions of particle board that are somewhat water resistant.

Evaluate the condition of your existing (particle board?) underlayment for damage, smoothness, stains and odors, and flatness. Proceed appropriately.

You may be able to see what the subfloor is and how thick your underlayment is when you remove the baseboards or the broken triangular piece of underlayment.

Buy an actual moisture meter to check for moisture. Pin units are typically a bit more accurate than pinless ones, but either can work 'ok'. You can check the underlayment, the baseboards, the drywall (Ha! Check the moisture in the drywall, get it? ), etc.

I'm not familiar with any tongue and groove particle board panels, all I've seen have been square edge. Doesn't mean that you DON'T have t&g particle board panels, just that I'm not familiar with any such panels. Particle board is not all that strong to begin with and cutting the thickness into thirds for the t&g would make it even weaker there.

And those gaps between panels don't look to good either.

I would NOT apply any water based things to either MDF or particle board, because they can both swell and be damaged by water or moisture.

I'm going to start removing the baseboard today. I'll pull up a piece of that corner to compare. It could be this tuff was put down over plywood by the carpet guys back when it was originally installed.

 

[TurnipTruck]

We remodeled a similar vintage house ten years ago, and we found the same ratty carpet-covered particleboard infrequently nailed over rosin paper on 1/2” plywood subfloor on 16” center joists. We glued and screwed 3/4” t&g subfloor topped with the same lifeproof LVP.

 

[duneslider]

I don't know why, mostly cause I am not old enough, but when I was a kid (early 80's) they were putting 3/8 partical board down on floors before all flooring. We did an addition on our house in the 90's and had to add it to the addition to match the height to the rest of the house. I later was a flooring contractor and I have torn tons and tons of it out of house built in the 70-80's. Its a **** shoot tearing it out, a lot of it was glued down as well as nailed/stapled. If it was glued its a pain to get it out. If its just nailed it comes up easy.

If it is all secured down good and no bubbles, squeaks, etc and you are just putting carpet or laminate in just leave it. Its been fine for 50 years and will be fine for another 50.

If it has gotten significant moisture you will know it, it literally just crumbles apart, turns completely black, and usually has a smell. I don't see anything concerning in the pictures you posted.

 

[dscheidt]

I don't know why, mostly cause I am not old enough, but when I was a kid (early 80's) they were putting 3/8 partical board down on floors before all flooring.

It was cheap, it’s flatter than plywood, and is softer under foot. Other than the problem with water damage, not holding nails and generally falling apart if anything happens to it, it is a perfect underlayment.

Last time I had to deal with it, we cut it and the subfloor out in strips, cutting the screws holding the subfloor to the joists after the first strip was out. Strips were cut with a circular saw set to the total depth of subfloor plus the particle board. Fasteners met Mr Sawzall. The subfloor was glued, but either they didn’t do a good job, or it had failed due to old age, so it came up pretty quickly.

 

[Motorman55]

Well the verdict is in. This is the subflooring.

After reading thru the suggestions and researching various subfloor material, turns out this is T&G OSB that was used a lot during that 1970's period for subflooring to save money, which makes sense since our house was built as part of an Adult community village HOA.

As to its construction. I pulled out a few nails on either side of a corner which enabled me to lift it just enough to slipped in a flat putty knife and I could feel and hear the crinkling of the fiberglass paper backing that's between the joists. There is no other flooring under it. Its definitly T&G and just nailed directly to the joists. It's at least 3/4" thick or whatever the thickness and was used as subflooring back in the 1970's.


Since its not damaged, not wet and I see no sign of mold, I'm inclined to just leave well enough alone as duneslider suggested and proceed with the installation of the Vinyl plank flooring.

To this end I will...

1. Make sure there are no nails or staples protruding up from the boards and sweep and vac well to remove any loose dirt/particles/staples etc.

2. Use a siliconized caulk in the large cracks just enough to fill the void and still allow for expansion/contraction.

I checked for the height differance between this floor and the adjoining hardwood flooring in the hallway. I will need to lay down 3/8" smooth one side plywood. That plus the thickness of the vinyl plank flooring will bring it up close to the height of the hallways' wood flooring. I'll need 5 full 4x8 x 3/8" sheets of plywood.

Then:

3. (Optional) I could still add Lifeproof 1.5mil Thick underlayment, which is the only one specifically made for Lifeproof products, and still stay within the height of the hallway floor. It's probably not really necessary but it would add a moisture barrier so it couldn't hurt. ($90.00 per 100 sq ft roll, I'd need 1 full roll and a partial) so 2 rolls it is.

4. Install the Lifeproof 22mil Vinyl Plank flooring leaving 1/4" gap min. all around.
5. Install new baseboard.
6. Finish with shoemoulding/quarter round.

I know its not ideal, but seems reasonable considering the shape the subfloor is in, it previously only having maybe two sets of new carpeting and padding put down over the houses' entire 45-48 year life span and I'm sure as heck not going to replace it with a third one.

I just updated this post....Wed 9:05 pm 1/21.

 

[Burt Shaver]

I have no particular expertise. Having said that, I shop vac the perimeter and any cracks. Then bleach the entire area. Maybe 5%. Then dry very thoroughly.

Kilz seems smart.

I like the life proof stuff.

Bleach is a no no, it corrodes metals. Nail heads. I seen a post from a guy who admitted to washing out the hull of his boat with bleach, corroded the motor mounts to a point they were non functional.

 

[bluedog225]

Bleach is a no no, it corrodes metals. Nail heads. I seen a post from a guy who admitted to washing out the hull of his boat with bleach, corroded the motor mounts to a point they were non functional.

I guess. I agree put it on particleboard or whatever that stuff is isn’t the best idea. I bleached the **** out of my shed to get rid of the rat piss smell. Nails are fine. Though I only use hot dip stuff. Imagine, uncoated, steel, inside a boat hull, might not fair as well.

 

[steves_001]

Well the verdict is in. This is the subflooring. After reading thru the suggestions and researching various subfloor material, turns out this is T&G OSB that was used a lot during that 70's period for subflooring to save money, which makes sense since our house was built as part of an Adult community village HOA.

As to its construction. I pulled out a few nails on either side of a corner which enabled me to lift it just enough to slipped in a flat putty knife and I could feel and hear the crinkling of the fiberglass paper backing that's between the joists. There is no other flooring under it. Its definitly T&G and just nailed directly to the joists. It's at least 3/4" thick or whatever the thickness and was used as subflooring back in the 1970's.


Since its not damaged, not wet and I see no sign of mold, I'm inclined to just leave well enough alone as duneslider suggested and proceed with the installation of the Vinyl plank flooring.

To this end I will...

1. Make sure there are no nails or staples protruding up from the boards and sweep and vac well to remove any loose dirt/particles/staples etc.
2. Use a siliconized caulk in the large cracks just enough to fill the void and still allow for expansion/contraction.

I checked for the height differance between this floor and the adjoining hardwood flooring in the hallway. I will need to lay down 3/8" smooth one side plywood. That plus the thickness of the vinyl plank flooring will bring it up close to the height of the hallways' wood flooring. I'll need 5 full 4x8 x 3/8" sheets of plywood.

Then:

3. (Optional) I could still add Lifeproof 1.5mil Thick underlayment, which is the only one specifically made for Lifeproof products, and still stay within the height of the hallway floor. It's probably not really necessary but it would add a moisture barrier so it couldn't hurt. ($90.00 per 100 sq ft roll, I'd need 1 full roll and a partial, so 2 rolls it is.
4. Install the Lifeproof 22mil Vinyl Plank flooring leaving 1/4" gap min. all around the walls.
5. Install new baseboard.
6. Finish with shoemoulding/quarter round.

I know its not ideal, but seems reasonable considering the shape the subfloor is in, it previously only having maybe two sets of new carpeting and padding put down over the houses' entire 45-48 year life span and I'm sures as heck not going to replace it with a third one.

I just updated this post....Wed 9:05 pm 1/21.

Good plan.

 

[Motorman55]

When I was checking for the height differance between this room and the hallway flooring, I pulled up the hardwood transition strip and I could see that this subflooring runs under the hard wood flooring of the hallway so its probably runs thru the whole house too.

The hardwood flooring in the hallway and former dining room was put down years ago by my In-Laws when they lived here as well they installed new carpeting in the living room. The bedrooms had newer carpeting when they first moved in the mid- 2000's.

This house when originally built had wall to wall carpeting installed in all the rooms except the bathrooms and kitchen. I'm thinking the carpets were replaced at least once maybe twice over the years. All carpeting is going eventually.

But I digress...now back to work.