Rotted subfloor, notched joist, & other problems that need repair

[highup]

Most likely vinyl sheet. Slight possibility that it could someday be vinyl plank, but right now I'm not getting my hopes up on the budget for that. I'm trying to keep it under $5k for the reno.

So far I have the prehung doors, the vanity, the vent fan/light, outlets, switches, screws, nails, paint, etc.

IIRC, you guys said if I do the vinyl plank I would have to install some sort of insulation underneath the house on the underside of the subfloor. So, it will probably be vinyl sheet.

I've been told the treated lumber corrodes aluminium, so I'm looking at using some sort of tape for the flashing and making sure to use galvanized screws and nails. I'll also need to get some sort of transition strips for any height differences between door threshold and the parquet flooring in the kitchen.

How much ground clearance under the house? If wind can blow water under the house, that really needs to be corrected.
About the treated plywood. Here's what it says:
For optimal performance of paint and stain coatings, allow treated wood to dry prior to application
Hot-dipped galvanized or stainless-steel fasteners and fittings are recommended
Safe when used as directed by the manufacturer's warranty

If it recommends to allow the plywood to dry before painting, it means something had to evaporate off of the plywood. What's evaporating or flashing, water or moisture, or petroleum products?
Some treated lumber needs to weather for quite a while if you want paint to stick.
You're not applying paint, but I'm concerned about what vapors might try to come up through the seams in the underlayment and affect the vinyl..... I mean by discoloration.
I'd find out the actual manufacturers name of that plywood and ask them about using it for interior sub flooring and especially about if it can affect vinyl flooring when used as you plan to.

They mention using hot dipped or stainless fasteners too. I'm wondering if the pressure treatment can affect the fasteners. That would mean you might need stainless or hot dipped fasteners fro the underlayment also.
Most ring shank nails are electro-galvinized, not hot dipped.

It would be nice to see insulation between the joists and a vapor barrier on the ground.

The 1/4" plywood doesn't mention flooring.:
Sanded panel for use in interior and exterior applications, such as cabinets, shelving, furniture, porch ceilings and soffits
Ideal project panel due to smooth, sanded face and attractive appearance when painted

This 1/4" plywood might not be smooth enough for underlayment and might have voids in the middle layer.... who knows. That's why it a lot less expensive.


You mentioned flashing...... not sure what you intend to flash.

 

[Nick]

You mentioned flashing...... not sure what you intend to flash.

I would think the joints where the underlayment butt together Hi..

 

[highup]

This may help a little. I 'll post it then read through it.......... how's that.
http://www.awpa.com/references/homeowner.asp

I looked again at the specs for the 3/4" plywood. It says non structural rated and not for floors walls book cases roofs etc.

Specifications
Series Name N/A
Actual Thickness (Inches) 0.47
Actual Width (Feet) 4
Actual Length (Feet) 8
Common Thickness (Inches) 1/2-in
Common Width (Feet) 4
Common Length (Feet) 8
Product Standards Non-structural rated
Weather Exposure Exterior
Finish Unfinished
Environmental Certification N/A
Water Resistant No
Fire Resistant No
Veneer Grade CC
Pressure Treatment Type Ecolife
Warranty Limited lifetime
Application as 4 x 8
For Use with Cabinet/Bookcases No
For Use with Floors No
For Use with Furniture No
For Use with Roofs No
For Use with Walls No
Type Plywood sheathing
Hardwood/Softwood Softwood
Wood Species Southern yellow pine
Edge Profile Square
Pressure Treated Yes

 

[highup]

More on moisture concerns with flooring.
https://www.apawood.org/high-moisture-and-wood-flooring

 

[Nick]

APA use to have 5 different on line tests For Certs .. Don't know if they still do ..

 

[Ernesto]

More on moisture concerns with flooring.
https://www.apawood.org/high-moisture-and-wood-flooring

As is the http://www.hpva.org/engineered-hardwood-flooring

Both are really steppin it up.

 

[zannej]

How much ground clearance under the house? If wind can blow water under the house, that really needs to be corrected.
About the treated plywood. Here's what it says:
For optimal performance of paint and stain coatings, allow treated wood to dry prior to application
Hot-dipped galvanized or stainless-steel fasteners and fittings are recommended
Safe when used as directed by the manufacturer's warranty

If it recommends to allow the plywood to dry before painting, it means something had to evaporate off of the plywood. What's evaporating or flashing, water or moisture, or petroleum products?
Some treated lumber needs to weather for quite a while if you want paint to stick.
You're not applying paint, but I'm concerned about what vapors might try to come up through the seams in the underlayment and affect the vinyl..... I mean by discoloration.
I'd find out the actual manufacturers name of that plywood and ask them about using it for interior sub flooring and especially about if it can affect vinyl flooring when used as you plan to.

They mention using hot dipped or stainless fasteners too. I'm wondering if the pressure treatment can affect the fasteners. That would mean you might need stainless or hot dipped fasteners fro the underlayment also.
Most ring shank nails are electro-galvinized, not hot dipped.

It would be nice to see insulation between the joists and a vapor barrier on the ground.

The 1/4" plywood doesn't mention flooring.:
Sanded panel for use in interior and exterior applications, such as cabinets, shelving, furniture, porch ceilings and soffits
Ideal project panel due to smooth, sanded face and attractive appearance when painted

This 1/4" plywood might not be smooth enough for underlayment and might have voids in the middle layer.... who knows. That's why it a lot less expensive.

You mentioned flashing...... not sure what you intend to flash.

Thanks. I think the floor is about 3' off the ground, but the ground is not really level so it's higher in some spots than others. A good portion of the house has skirting-- some of which goes all the way to the ground and blocks rain. But, we get high winds and a LOT of rain. It's not so much the wind blowing as is the splashing of the rain when it runs off the roof. We currently don't have gutters or any sort of system set up to direct water flow away from the house. Underneath the house the dirt is quite sandy, so water percolates rather quickly. We are on high ground so we don't really get flooding. I think my two main concerns are pipe ruptures getting stuff wet and the fact that the air has high humidity.
OK. So that cheaper pine plywood might not be good for flooring?
Answer to flashing question under Highup's post.

You mentioned flashing...... not sure what you intend to flash.

I would think the joints where the underlayment butt together Hi..

Sorry, I should have clarified that the flashing was for under/around the exterior door. I want to protect the floor underneath the threshold so it doesn't rot like the current one did.

This may help a little. I 'll post it then read through it.......... how's that.
http://www.awpa.com/references/homeowner.asp

I looked again at the specs for the 3/4" plywood. It says non structural rated and not for floors walls book cases roofs etc.

Specifications
Series Name N/A
Actual Thickness (Inches) 0.47
Actual Width (Feet) 4
Actual Length (Feet) 8
Common Thickness (Inches) 1/2-in
Common Width (Feet) 4
Common Length (Feet) 8
Product Standards Non-structural rated
Weather Exposure Exterior
Finish Unfinished
Environmental Certification N/A
Water Resistant No
Fire Resistant No
Veneer Grade CC
Pressure Treatment Type Ecolife
Warranty Limited lifetime
Application as 4 x 8
For Use with Cabinet/Bookcases No
For Use with Floors No
For Use with Furniture No
For Use with Roofs No
For Use with Walls No
Type Plywood sheathing
Hardwood/Softwood Softwood
Wood Species Southern yellow pine
Edge Profile Square
Pressure Treated Yes

Ok. So that particular pressure treated plywood would be a no go for the subfloor. Lowes doesn't always have the search parameters I'd like to have. Home Depot has some better search tools but a lot of stuff there is not available in my nearest store nor is it available for shipping. I'm having a hard time finding stuff specifically for flooring.

Looks like from the chart I would need UC3A?

Just for funsies I'm in an online chat with someone from Lowes. Let's see if they actually know stuff or if they will give bad advice. LOL.

Edit: Looks like it was bad advice. They tried to recommend OSB. I'm going to go out on a limb here, but I don't think it would be a good subfloor. It might be somewhat ok for a substrate, but I've heard that some flooring installers refuse to install over OSB.
This came up as an option. Plytanium tongue and groove 23/32 plywood. It looks like it might be good for the bottom layer.
1. Would the top layer also have to be floor grade? (I'm guessing "yes", but figured I'd ask just in case). Looks like PS1-09 is floor grade.
2. Should I top it off with Plytanium 11/32 plywood? Or 15/32?
3. Is it worth the extra $1 for tongue-and-groove vs just regular?
4. Do you think it would be necessary to use some sort of wood sealant or treatment on it or do you think it would hold up as is?

 

[highup]

Thanks. I think the floor is about 3' off the ground, but the ground is not really level so it's higher in some spots than others. A good portion of the house has skirting-- some of which goes all the way to the ground and blocks rain. But, we get high winds and a LOT of rain. It's not so much the wind blowing as is the splashing of the rain when it runs off the roof. We currently don't have gutters or any sort of system set up to direct water flow away from the house. Underneath the house the dirt is quite sandy, so water percolates rather quickly. We are on high ground so we don't really get flooding. I think my two main concerns are pipe ruptures getting stuff wet and the fact that the air has high humidity.
OK. So that cheaper pine plywood might not be good for flooring?
Answer to flashing question under Highup's post.


Sorry, I should have clarified that the flashing was for under/around the exterior door. I want to protect the floor underneath the threshold so it doesn't rot like the current one did.


Ok. So that particular pressure treated plywood would be a no go for the subfloor. Lowes doesn't always have the search parameters I'd like to have. Home Depot has some better search tools but a lot of stuff there is not available in my nearest store nor is it available for shipping. I'm having a hard time finding stuff specifically for flooring.

Looks like from the chart I would need UC3A?

Just for funsies I'm in an online chat with someone from Lowes. Let's see if they actually know stuff or if they will give bad advice. LOL.

Edit: Looks like it was bad advice. They tried to recommend OSB. I'm going to go out on a limb here, but I don't think it would be a good subfloor. It might be somewhat ok for a substrate, but I've heard that some flooring installers refuse to install over OSB.
This came up as an option. Plytanium tongue and groove 23/32 plywood. It looks like it might be good for the bottom layer.
1. Would the top layer also have to be floor grade? (I'm guessing "yes", but figured I'd ask just in case). Looks like PS1-09 is floor grade.
2. Should I top it off with Plytanium 11/32 plywood? Or 15/32?
3. Is it worth the extra $1 for tongue-and-groove vs just regular?
4. Do you think it would be necessary to use some sort of wood sealant or treatment on it or do you think it would hold up as is?

What is the total thickness you need to go up to meet any adjoining doorways?
On the other side of the doorway, do you have future plans to add new underlayment there at some point in time?

OSB is often used for the subfloor, but never the underlayment. Not being smooth is only one problem for underlayment. If you add glue, the wetness of the adhesive can cause some of the chips or flakes, to swell and show through.
For the subfloor, OSB works, but doesn't hold fasteners nearly as well as plywood.
T&G might work good for the subfloor, if the joist spacing is beyond what it should be. You wouldn't want T&G for the underlayment.... then again, you won't find T&G in 1/3", 3/8" or 1/2" anyway.

If I read your questions correctly, you mean 32/32 for the subfloor and 11/32 for the underlayment. Both say for flooring and the 23 /32 I see is T&G, which might work better if the joists were farther apart than they should be. You might want to add adhesive to the groove when you install the sheets.
The thinner one (11/32") is graded BCX. ACX would have a better surface then BCX, meaning less floor prep.
Problem you have is they show you a pretty photo, not what you are actually buying........... I hand pick the sheets I buy to avoid surface plugs, patching and irregularities in the plywood face that will need to be corrected after installation.
If I don't use a true underlayment grade, I hand inspect and look for the grade ACX or CCPTS.
CCPTS means it has no voids in the center core. The "P" is for plugged. ACX may have small voids in the center plys. When hand selecting, I have a way to "listen" for the voids by lightly rubbing the surface with my fingertips. ...when you rub across the surface, you hear a sort of hissing sound. The sound will change when you rub on a void or hollow spot under the surface layer.

Box stores have funny names for plywood. Platinum? sounds pretty cool.
We only have actual grade stamps, ACX, BCX, CDX, CCPTS etc.

 

[zannej]

What is the total thickness you need to go up to meet any adjoining doorways?
On the other side of the doorway, do you have future plans to add new underlayment there at some point in time?

OSB is often used for the subfloor, but never the underlayment. Not being smooth is only one problem for underlayment. If you add glue, the wetness of the adhesive can cause some of the chips or flakes, to swell and show through.
For the subfloor, OSB works, but doesn't hold fasteners nearly as well as plywood.
T&G might work good for the subfloor, if the joist spacing is beyond what it should be. You wouldn't want T&G for the underlayment.... then again, you won't find T&G in 1/3", 3/8" or 1/2" anyway.

If I read your questions correctly, you mean 32/32 for the subfloor and 11/32 for the underlayment. Both say for flooring and the 23 /32 I see is T&G, which might work better if the joists were farther apart than they should be. You might want to add adhesive to the groove when you install the sheets.
The thinner one (11/32") is graded BCX. ACX would have a better surface then BCX, meaning less floor prep.
Problem you have is they show you a pretty photo, not what you are actually buying........... I hand pick the sheets I buy to avoid surface plugs, patching and irregularities in the plywood face that will need to be corrected after installation.
If I don't use a true underlayment grade, I hand inspect and look for the grade ACX or CCPTS.
CCPTS means it has no voids in the center core. The "P" is for plugged. ACX may have small voids in the center plys. When hand selecting, I have a way to "listen" for the voids by lightly rubbing the surface with my fingertips. ...when you rub across the surface, you hear a sort of hissing sound. The sound will change when you rub on a void or hollow spot under the surface layer.

Box stores have funny names for plywood. Platinum? sounds pretty cool.
We only have actual grade stamps, ACX, BCX, CDX, CCPTS etc.

After I talked to the folks at Lowes, I started looking on Home Depot now that I had a little bit of a better idea of what to look for.
I found this: https://www.homedepot.com/p/23-32-in-x-4-ft-x-8-ft-RTD-Sheathing-Syp-166103/100041308
And the link to the specs is for the Plytanium. It's not pressure treated but it's supposed to be exterior grade and it says it can be used as a subfloor. It's less expensive than what Lowes has. It looks like they have 62 in stock at the nearest store, so I could look at them.

Would it be a good idea to use a wood sealant on the subfloor?

I will have to see what the current thickness of the subfloor and underlay is before I know for certain what size it needs to be. From what I understand, the 23/32 is 1/32 smaller than 3/4". The 11/32 is more than 1/4" though.

Right now the floor is bare plywood because the cheap vinyl sheet ripped all to hell and we had to remove it (it kept getting caught on the bottom of the exterior door). The kitchen floor sticks up a bit more because it has parquet flooring so there is a teeny step down from that doorway. The nearby bedroom has thick carpet so it sticks up a bit more. The closet doesn't really matter (just that the door will have to clear) and the bathroom will be the same height bc it's being redone.

I think so long as the combined subfloor and underlayment are equal to or lower than the kitchen floor, it should be ok. But, I will endeavor to find out the total height when the weather warms up a bit more and I can poke a hole somewhere to find out.
Right now I'm leaning toward going with 23/32 and 11/32.

Just to clarify, the underlayment layer has to be floor supporting grade as well, yes?

What about this for the underlayment? https://www.homedepot.com/p/11-32-i...ellow-Pine-Plywood-Sheathing-166065/100003677
Nearest store has over 120 in stock.

I'm not too worried about the surface being pretty or smooth. My current floor sucks-- it still has some of the glue from the parquet that used to be there.

Is it a bad idea to put wood putty over the decking screws used to secure the boards?

Also, I read this:

To avoid damage to the surface, install underlayment immediately before laying the finish flooring. For maximum stiffness, install underlayment with the face grain perpendicular to floor joists, and offset underlayment panel ends from subfloor panel ends by at least one joist space.

I'm trying to visualize the offset, but my brain is not working. Is the offset necessary? I'm not sure how I would accomplish that given that the space is only 2 boards wide and 2 boards long.

Would using the nailgun be better than using decking screws? Or should I use a combo of both? (nail gun to secure first and decking screws to make sure it stays tight?)

Edit: on a side note, I'm seriously thinking of getting the sheets cut in half so I will have 4x4 to work with (since the full sheets weigh over 60lbs and will be harder to lift). 4x4 will also fit in my truck bed with the tailgate up. I know it's more seams, but it would make it so much easier for maneuvering and such.

 

[highup]

My brain's goin' fuzzy, so I'll take another look here tomorrow............ oh shesh it is tomorrow.

 

[highup]

After I talked to the folks at Lowes, I started looking on Home Depot now that I had a little bit of a better idea of what to look for.
I found this: https://www.homedepot.com/p/23-32-in-x-4-ft-x-8-ft-RTD-Sheathing-Syp-166103/100041308
And the link to the specs is for the Plytanium. It's not pressure treated but it's supposed to be exterior grade and it says it can be used as a subfloor. It's less expensive than what Lowes has. It looks like they have 62 in stock at the nearest store, so I could look at them.

Would it be a good idea to use a wood sealant on the subfloor?

I will have to see what the current thickness of the subfloor and underlay is before I know for certain what size it needs to be. From what I understand, the 23/32 is 1/32 smaller than 3/4". The 11/32 is more than 1/4" though.

Right now the floor is bare plywood because the cheap vinyl sheet ripped all to hell and we had to remove it (it kept getting caught on the bottom of the exterior door). The kitchen floor sticks up a bit more because it has parquet flooring so there is a teeny step down from that doorway. The nearby bedroom has thick carpet so it sticks up a bit more. The closet doesn't really matter (just that the door will have to clear) and the bathroom will be the same height bc it's being redone.

I think so long as the combined subfloor and underlayment are equal to or lower than the kitchen floor, it should be ok. But, I will endeavor to find out the total height when the weather warms up a bit more and I can poke a hole somewhere to find out.
Right now I'm leaning toward going with 23/32 and 11/32.

Just to clarify, the underlayment layer has to be floor supporting grade as well, yes?

What about this for the underlayment? https://www.homedepot.com/p/11-32-i...ellow-Pine-Plywood-Sheathing-166065/100003677
Nearest store has over 120 in stock.

I'm not too worried about the surface being pretty or smooth. My current floor sucks-- it still has some of the glue from the parquet that used to be there.

Is it a bad idea to put wood putty over the decking screws used to secure the boards?

Also, I read this:

I'm trying to visualize the offset, but my brain is not working. Is the offset necessary? I'm not sure how I would accomplish that given that the space is only 2 boards wide and 2 boards long.

Would using the nailgun be better than using decking screws? Or should I use a combo of both? (nail gun to secure first and decking screws to make sure it stays tight?)

Edit: on a side note, I'm seriously thinking of getting the sheets cut in half so I will have 4x4 to work with (since the full sheets weigh over 60lbs and will be harder to lift). 4x4 will also fit in my truck bed with the tailgate up. I know it's more seams, but it would make it so much easier for maneuvering and such.

As far as the offset, always offset the seams. Most people want to do it the easiest way by starting in the same corner or a straight wall just like the original sheets were installed. Don't do that.
If the room is only two sheets wide, cut 6", 12" or 24" off one side of your first new board so that the seam in the top board does not line up with the seam or seams in the existing floor boards. That's a must do, not an option.
If you stack seams on top of each other it weakens the joint and allows movement of that joint. Offsetting may take a few more minutes but time isn't that important. Offsetting strengthens the floor.
Hope that's what you were asking about.
4X7's or 4X6's would probably fit in the truck too....... that puts seams closer to a wall instead of the middle. I'd try for full sheets personally, as long as you can strap them down well so they don't fly out.
If my diagram is same as your room, maybe leave one board full size and have em cut the second board into two 2'X8' pieces.

 

[highup]

Would it be a good idea to use a wood sealant on the subfloor?

I will have to see what the current thickness of the subfloor and underlay is before I know for certain what size it needs to be. From what I understand, the 23/32 is 1/32 smaller than 3/4". The 11/32 is more than 1/4" though.

Sealant, like marine varnish? I suppose that could be done and wouldn't hurt if the first layer is going over the actual floor joists. That would protect it from moisture under the house.
I may have missed something along the way. I'm confused about the construction and what you are doing here. Are you going over an existing plywood floor or over bare joists?
If going over existing plywood I think you need just a top layer ...which would make that layer your underlayment.

If going over existing plywood, how thick is it ......and also is that plywood a single layer?
I'm trying to determine how many layers are on the floor from the joists on up and how thick the layers are.
......then from there, how much higher do you need to go?

 

[zannej]

Thanks highup.
My plan is to pull up the original floor and put the plywood over bare joists. I know there is water damage all the way through the floor in at least some sections and it will be easier to just replace it all instead of trying to patch and match the existing level. It will also give me the opportunity to level and reinforce the joists (as well as to run plumbing while the floor is out).

I have a crew cab truck with a shortened bed-- it's only 5' long. I'm not worried about things flying out, I'm worried about boards hanging over the end breaking or getting damaged. It's an hour drive back home and the last 15 to 20 minutes is on unpaved roads (lots of bumps). But, it might be better to leave them at full length. I'll have to see when I go to get materials.

I know the subfloor is supposed to run with the grain perpendicular to the joists, but could I put the top layer running parallel to the joists as a way of offsetting? (I'm guessing not, but I want to be certain).

I'm exhausted from all the running around to doctors and taking my bro to the ER and stuff so my brain is in a fog.

 

[DarisMulkin]

They make an extension bar type thing that can be hooked into your trailer hitch and can be adjusted up to the height of the truck bed. I have one I use when hauling carpet. Or do like I did for years. Take a sheet of ply wood and only put it in the truck about half way. Then pile everything on top.

:camping:

Daris

 

[zannej]

Thanks, Daris. I'll have to look for that. If I can't find one I think what I will most likely end up doing is putting them at an angle with the tailgate up so they will be more visible to vehicles behind me and make sure they are secured and make sure I have a red marker/tape on the ends so they are clearly visible to drivers behind. I know carrying them flat is ideal, but knowing drivers in this area, they would likely run in to the boards-- and I wouldn't have use of my backup camera since it is on the tailgate.

I think what highup suggested is starting to make more sense now that my brain fog is clearing. So, I could cut one of the boards in half lengthwise and put the 24"wide (ok, I know it won't be a full 24") portions on the edges and the 48" portion in the middle to offset the seams, correct?

 

[highup]

24 isn't what it has to be, it just needs to be offset 6" or more... I think 6" is enough. So make it an offset, but an offset that puts the top seam where you would prefer it to be.
Even 1 foot makes the sheet lighter, so it's your choice.

 

[highup]

Another way would be putting a couple 2X4's or 2X6's under the stack of stuff for support, but even with 3 feet of overhang, I can't imagine 3/4" plywood getting damaged. ...if it does, you airbags will go off too.

 

[zannej]

Daris, I think I found what you were talking about. This? https://www.amazon.com/dp/B01AW6BEBK/?tag=skimlinks_replacement-20

That looks pretty sweet. I think it might actually have the center bar low enough that it would not interfere with the backup camera too much. I hope at least.

I forgot to mention that I intend to use something like Thompson's Wood seal on the subfloor boards (prior to installing). I think I have a bucket of it somewhere. I'm debating whether or not to use any sealant on the 2nd layer.

Highup, good point. I think the thing Darris suggested would work. I found one that comes with a red flag to put on the end of the lumber.

I was just thinking that getting a couple of the boards ripped in half would just be easier (plus I like things to be symmetrical). Also, that way I know that none of the seams will fall where I need to cut holes for plumbing.

Edit, Just another thought: It just occurred to me that since there are 4 boards total, there will be seams in the middle so I will need to stagger from side to side and top to bottom (if that makes sense). Or would it be ok to have the same seams for when the ends of the top boards secure to the joist?
Staggered idea:

 

[highup]

Daris, I think I found what you were talking about. This? https://www.amazon.com/dp/B01AW6BEBK/?tag=skimlinks_replacement-20

That looks pretty sweet. I think it might actually have the center bar low enough that it would not interfere with the backup camera too much. I hope at least.

I forgot to mention that I intend to use something like Thompson's Wood seal on the subfloor boards (prior to installing). I think I have a bucket of it somewhere. I'm debating whether or not to use any sealant on the 2nd layer.

Highup, good point. I think the thing Darris suggested would work. I found one that comes with a red flag to put on the end of the lumber.

I was just thinking that getting a couple of the boards ripped in half would just be easier (plus I like things to be symmetrical). Also, that way I know that none of the seams will fall where I need to cut holes for plumbing.

I'm not so sure about Thompsons for a sealer. Maybe others can give a recommendation. Definitely don't seal the second layer.

I was just trying to cheap out on a support system idea for ya. That support might be something good for future uses.

 

[highup]

The 1st image you showed needs to be staggered on the joists also. You never want 4 corners to come together. That severely weakens the floor structure. You need to move two of those sheets up one joist........... yes, even if it means creating one additional seam.
We're makin it hard ain't we.