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

[Jon]

Used to use particle board here for sub flooring but now ply is used in all wet areas with the vinyl just glued on top of the ply after sanding or similar

http://www.plywoodcity.co.nz/shop/Flooring.html

 

[highup]

1. Would I do the floor in 2 layers like the floor in my bathroom? They did a bottom layer, then a moisture barrier with another layer of plywood on top. (It actually saved the subfloor from rotting when there was water damage to the top layer that turned to mud-- happened in the adjacent bathroom with only one layer & toilet fell through the floor with my brother on it). Or would I just use a single thick piece of plywood?

What is the current subfloor material and it's thickness? No manufacturer of vinyl flooring recommends installation over a single layer floor because of joint movement. The underlayment seams are always offset from the subfloor seams to eliminate that joint or seam movement. So yea, two layers bringing you up even with that kitchen doorway.

 

[Floorist]

I don't know enough about treated plywood or 2X material for the subfloor, but I think most of it has the ability to discolor the vinyl over time. I'd call the manufacturer first to see if they recommend it for an interior subfloor material. I know in Hawaii they use a lot of treated wood, but I'd make sure it's OK for use as a subfloor as far as vinyl goes. Call the manufacturer about a particular product that you may use.

You are right. Treated wood can bleed through the vinyl. At least the old treated wood (arsenic treated) did a lot of times. It also stayed damp and the adhesive had trouble holding to it.

 

[highup]

You are right. Treated wood can bleed through the vinyl. At least the old treated wood (arsenic treated) did a lot of times. It also stayed damp and the adhesive had trouble holding to it.

Yup, that's why I think it's best if Zannej checks out the type of treated wood available in her area, then calls the manufacturer for more info. Maybe there's some treated stuff that will work. Never seen anything but that green smelly stuff around here, and like you said, that won't work.

 

[zannej]

Pressure treated plywood seems to be about the only kind available here. I wonder if I should use two layers of that or one layer of pressure treated on the underside and untreated with a nicer finish on the top. Still need to work out the thicknesses.

I'm not certain what thickness the subfloor currently is because the only visual I have is the edge under the door threshold-- and it's rotted.

I'm going to have to find a way to cut through and take a look-- but it will have to wait until after the tropical storm passes. I need to find the attachment for my drill that cuts holes for doorknobs or something to see if I can get a sample chunk of the floor to see thickness. I also need to figure out where the joists are located. I know they run east to west (the exterior wall with the rotting door runs north to south).

I actually need to take down a wall to get a better look at some of the floor, but I need to get my prybar back from a friend (if his meth-head father didn't steal it).

 

[Ernesto]

Just drill a hole.

 

[zannej]

Still procrastinating on this and the weather has been really hot.

Is there a good/easy way to level the subfloor (without using leveling compound on top) if the joists are not level?

 

[zannej]

Now the weather has been too cold and we had some pipes freeze. Waiting for spring I guess, but in the meantime, I want to get a supply list together.
This is my latest sketch of the revisions I plan to make to the current layout (knocking down some non-load bearing walls).

By my math, if I took down the two walls plus the one between the laundry room and bathroom (temporarily) while working on the floor, I should be able to re-do it with either four 8x4 sheets or eight 4x4 sheets (I'm not forgetting I will have to double that but have half of them 3/4" and half 1/4"). I'll have to price them out and see which will give me the best bang for my $.

Since I don't expect there to be joists at all of the ends, I will want to add some extra ones to support edges near walls. I want to verify what size planks I will need. Should I go with 2x8 or 2x10? (I think the current joists are roughly spaced 24" apart). I was thinking, depending on how I do them, I could have 2x8s on the west (left) side but do 2x10s under where the washing machine and bathtub will be. What do you guys think?

Can I use drywall tape and spackle or something to smooth out seams so the floor will be smoother before I put down vinyl sheet?

 

[highup]

Now the weather has been too cold and we had some pipes freeze. Waiting for spring I guess, but in the meantime, I want to get a supply list together.
This is my latest sketch of the revisions I plan to make to the current layout (knocking down some non-load bearing walls).

By my math, if I took down the two walls plus the one between the laundry room and bathroom (temporarily) while working on the floor, I should be able to re-do it with either four 8x4 sheets or eight 4x4 sheets (I'm not forgetting I will have to double that but have half of them 3/4" and half 1/4"). I'll have to price them out and see which will give me the best bang for my $.

Since I don't expect there to be joists at all of the ends, I will want to add some extra ones to support edges near walls. I want to verify what size planks I will need. Should I go with 2x8 or 2x10? (I think the current joists are roughly spaced 24" apart). I was thinking, depending on how I do them, I could have 2x8s on the west (left) side but do 2x10s under where the washing machine and bathtub will be. What do you guys think?

Can I use drywall tape and spackle or something to smooth out seams so the floor will be smoother before I put down vinyl sheet?

Last question first....... Nope. Use a floor patching compound only. No mesh. Spackle or anything for wall repair has zero strength. Before any floor patching compound is applied, be sure the underlayment seams are properly spaced so there is no movement.

 

[Floorist]

And don't use a gypsum based floor patch.

 

[zannej]

Last question first....... Nope. Use a floor patching compound only. No mesh. Spackle or anything for wall repair has zero strength. Before any floor patching compound is applied, be sure the underlayment seams are properly spaced so there is no movement.

And don't use a gypsum based floor patch.

Thank you. I was concerned that the drywall stuff would crumble. The damage to the floor was patched by gypsum stuff in the first place and it broke apart (there had been some significant damage to the substrate and the flooring guy just poured in the white powder and added water) when we moved the appliances around. I'm hoping the seams will be smooth enough. I was also considering using wood putty or something on the plywood seams.

When you say "properly spaced" what do you mean? As in leaving a small gap for expansion between the plywood sheets?

Someone suggested that I should see what size joists I currently have and for whatever I add, I should use the same size. Will be "fun" measuring that. I wish I hadn't gained so much weight because I might have been able to squeeze under there-- although at 150lbs I still did get my fat a** stuck under a low pipe once (I was running some telephone wire from the box at the front all the way to the back of the house). As a kid, I used to crawl under the house all the time just for fun.

 

[Nick]

considering using wood putty or something on the plywood seams. NO..

Mix up some Ardex floor patch to a pea soup consistency..

I use a 6" trial.. Others may prefer a wider one ..

 

[highup]

And don't use a pre-mixed floor patch.
The guy I am working for used some from Home Depot. The patch had sand in it that prevented it from smoothing to a feather edge. I scraped it all off and used Feather Finish like Nick mentioned

 

[zannej]

Thanks guys!
If I get everything installed level, I'm hoping I won't even need to do anything on the seams.
A buddy of mine just used duct tape on his floors under the vinyl sheet. It didn't really work well. LOL.

 

[Nick]

Seem it .. It's not hard ..

 

[zannej]

I'm not sure I understand, Nick. You mean use the Ardex?

I saw that there is something called "seam tape" but I don't think it's for floors. LOL.

 

[Nick]

Yes .. Ardex Feather finish .. or you can use Henry .. A lot cheaper in price ..

https://images.homedepot-static.com...self-leveling-waterproofing-12163-64_1000.jpg

It's like $20.00 a bag @ Lowes ..

 

[zannej]

Thanks, Nick!
I know this was somewhat discussed before, but my memory is total crap.
I discovered that the plywood I was thinking of getting only comes in 3/4" and 1/2". Although, I could still put 1/2" on top of 3/4". I know I definitely want the 3/4" because it is "severe weather" above ground pressure treated since the underside may get splashed with water from rain and it's damp outside, but, would it be ok to use something else for the 2nd plywood layer? Could I do the 3/4" treated and 1/4" something else? Preferably something cheaper than $35...
Could I use Plytanium 1/4 CAT PS1-09 Pine Sanded Plywood on top? Or would it be better to use Severe Weather 1/2-in Common Southern Yellow Pine Plywood Sheathing?

We would get a 10% military discount but sales tax is 10.5%.

I'm also wondering if I could find some plywood online and have it shipped for a decent price. Right now I'm looking at about $284 (not counting gas expenditure to get there and back) for 8 sheets. Would be slightly lower if I could use the untreated pine.

What do you guys recommend? And what does all the CAT and other stuff stand for? category?

 

[Nick]

YW.. What kind of floor are you installing over the Plywood ?

 

[zannej]

YW.. What kind of floor are you installing over the Plywood ?

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.