# underlayment for stick on tiles or vinyl



## novice40 (Jul 11, 2008)

I need some help with completing a small job.
I am going to replace some vinyl tiles covering a small staircase in a garage.

I removed the old tile(there were two layers) from the landing.
Underneath there is hardboard (masonite) with the rough side up.

I want to elevate the landing for a cosmetic reason that would be hard to describe without seeing it.

So I figured on using one seemless sheet of 3/16 or 1/8 hardboard over the top but questioned which side should face up , smooth or rough side.

But in reading other posts some recommend against using hardboard , some say its ok for small jobs.

Help me to decide my best route here considering that this is a garage so it isn't an area that I want to throw a lot of money at .

The tile only cracked at the stair nosing which was a type that has a lip that goes under the tile .

I plan to remove that nosing and use a different type that just butts up against the vinyl.



So making a decision on the underlayment is my obstacle , the landing is like 4 x 5 and I dont want to spend a fortune on expensive underlayment.

Hardboard didn't seem to cause trouble with the old tiles but there were 2 layera and the bottom layer was a thicker glue down tile not self stick , so I doen't know if that helped it survive.

The seems weren't even filled on the old hardboard.



Also with the underlayment I'm reading that I should use staples but I don't have a staple gun.
I have a finish nailer and was intending on installing hardboard over what is there using construction adhesive and finish nails. 

These nails from this gun as hard to pull out and leave a small indent so I figured that would leave a surface that wouldnt show anything and wouldn't need to be filled.

I cant see renting a staple gun for something like this.

There is also a small storage closet that has a high step up (it's located over the staircase to the basement.
It has particleboard on the 3 x 4 'floor' , I figured I'd throw a layer of hardboard over it and stick the same tiles down.

I need your input and appreciate your help.


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## Nestor_Kelebay (Jun 17, 2008)

I'd pull out that masonite and use "fir plywood" type underlayment. The masonite will swell up and get soft if it gets wet. Also, the difference between ordinary plywood and "plywood type underlayment" is that plywood is allowed to have voids in the interior plies that can result in soft spots on the floor. In underlayment, these voids are filled so you don't get those soft spots.

You don't need a pnuematic stapler to put down underlayment. In the bathrooms in my building, it was just nailed down and that lasted 50 years. People recommend using ring shank nails to ensure the underlayment doesn't come up, but in my view a better solution would be to use deck screws on 6 inch centers.

So, just pull out that masonite and the tile that's stuck to it, and build up the floor height as desired before putting down underlayment. I'd screw it down so that it's easy to remove in future. Use flat head screws and counter sink them. Then, fill in the countersinking with a cement based floor leveler.

Then, just install your floor tiles over that.


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## novice40 (Jul 11, 2008)

Thank you for replying.
Here is what concerns me the most .
The subfloor is toungue and goove and has some movement it squeeks when you walk on it.
Although I could add screws after scrapping the old underlayment , I worry aboout the floor leveler crumbling (coming loose) and showing thruogh the self stick tiles.
The old floor had 2 layers of tile , the lower layer was a non self stick , it was a thicker tile.
I'm thinking it prevent any telegraphing of nails and seams, in fact the old underlayment has nails that were coming up and seams that weren't filled .
The masonite was rough side up yet the floor was smooth except for the top layer of self stick tiles cracking from the stair nosing underneath.
(I wish I could have saved that bottom layer of tile.)

I have never installed underlayment , can I feel confident that a single layer of self stick vinly tiles will work out ok ?
The stuff is very thin.
The stairs will be the same self stick , so if it doesn't hold up I either need enough spare tile on hand for the whole landing to make a repair, or I'll be stuck with redoing the stairs and risers with all new self sticks too.

I need to avoid any error on this with having done any underlayment prior.

You say screw 6" apart where should I locate them ?
Instinct tells me floor joists only to have as few as possible and screw right into the joists for a strong hold.

But should the screws only go in the floor joists or in the feild too ?
I see some people say dont put them in the joists , make them only long enough so they don't come through the subfloor and put them in the field too.


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## Nestor_Kelebay (Jun 17, 2008)

> Here is what concerns me the most .
> The subfloor is toungue and goove and has some movement it squeeks when you walk on it.
> Although I could add screws after scrapping the old underlayment , I worry aboout the floor leveler crumbling (coming loose) and showing thruogh the self stick tiles.


If it squeeks when you walk on it, you can drive some deck screws through the subfloor down into the joists to clamp the subfloor down tight to the joist again. That squeeking is the result of the joists being installed when they were still to wet. Wood shrinks as it dries, and if the joist wasn't fully dry when it was installed, it will continue to shrink and a gap will grow between the top of the joist and the bottom of the subfloor. The squeeking noise you hear is the subfloor and nail vibrating as they rub against each other when you walk over the floor.

If I were you, I would mark a line where the nails going into the joists are, and predrill, countersink and drive screws in along that line to clamp the subfloor down tight to the joists to eliminate that squeeking.

You put the screws down through the SUBFLOOR into the floor joists. Those screw heads will be covered by the underlayment.




> The old floor had 2 layers of tile , the lower layer was a non self stick , it was a thicker tile.
> I'm thinking it prevent any telegraphing of nails and seams, in fact the old underlayment has nails that were coming up and seams that weren't filled .
> The masonite was rough side up yet the floor was smooth except for the top layer of self stick tiles cracking from the stair nosing underneath.
> (I wish I could have saved that bottom layer of tile.)


The bottom layer of tiles were probably something called "linoleum tiles" which were popular back in the 50's and 60's. The had similar construction to linoleum; a tarpaper backing with a vinyl wear layer on top. The problem was that the tar would eventually dry out so that the paper backing would absorb moisture and swell. That caused the corners and edges of the tiles to lift, and often get broken off.




> I have never installed underlayment , can I feel confident that a single layer of self stick vinly tiles will work out ok ?
> The stuff is very thin.
> The stairs will be the same self stick , so if it doesn't hold up I either need enough spare tile on hand for the whole landing to make a repair, or I'll be stuck with redoing the stairs and risers with all new self sticks too.


I expect this layer of self stick tiles will last as long as the last installation did. Longer if you address the problem with them cracking on the stair nosings.
I need to avoid any error on this with having done any underlayment prior.



> You say screw 6" apart where should I locate them ?
> Instinct tells me floor joists only to have as few as possible and screw right into the joists for a strong hold.
> 
> But should the screws only go in the floor joists or in the feild too ?
> I see some people say dont put them in the joists , make them only long enough so they don't come through the subfloor and put them in the field too.


You screw your subfloor down to the joists with longer screws, like 2 or 3 inch screws.

You should nail or screw your underlayment down to the subfloor with nails or screws that are just long enough to protrude out the bottom of that subfloor. Basically, what you want is for your nails or screws to be 1 inch from the edge of your underlayment on approximately 6 inch centers.

So, for example, if your underlayment is 1/4 inch thick and your subfloor is 3/4 inch thick, then if it were me, I'd use 1 1/4 inch long flat head screws. I'd predrill the holes and countersink them so that the heads of the screws were below the surface of the underlayment. If the underlayment was 36 inches X 48 inches, I'd put my nails or screws in so they were 1 inch from the edge, so the "field" would be 34 X 46 inches. So, what I'd probably do is have 7 rows spaced 5 5/8 inches apart (with the last row being 5 7/8 inches from the previous row, by 9 rows spaced 5 3/4 inches apart. I wouldn't go much below a 5 1/2 inch spacing. Considering this is a flexible flooring you're going to be installing, I'd opt for a 7 or even 8 inch spacing between rows rather than go below 5 1/2 inches between rows of screws or nails.

Don't worry about the floorleveler coming loose. Mapei's cement based floor leveler, called "PlaniPatch" has a recommended "additive" (pronounced "adhesive" and called "PlaniPatch Plus") that you mix with the floor leveler to make it stickier and dry harder. You mix that Plus additive with 3 parts water and use that solution to mix up your floor leveler powder into a slurry. Then fill your seams and countersunk screws and nail holes with that slurry. It'll never come loose.


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## novice40 (Jul 11, 2008)

Thanks Nestor I hope I will be able to find that product at Home Depot when I get to that stage.

After I lifted the underlayment I found several problems with the subfloor for the landing .
They used 3/4 pine panel like used for cabinet work it's all splitting.
There is only one joist in the center , so it's 23 inches on center .
The pine panels werent sittiing flush due to the stucture (the floor joist isnt flush with the rim joists) and at the edge going toward the kitchen the pine panels were only overlapping the rim joist 1/4 inch.
The tongue and groove from the kitchen covered the rest of that joist.

I had to cut off some of the tongue and groove coming from the kitchen and I'll have to beef up the structure and lay a new sub floor for the stair landing.
NOthing is ever easy LOL.

Can you give me some ideal of what to buy/what not to buy for the plywood subfloor ?


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## Nestor_Kelebay (Jun 17, 2008)

If you're replacing a plywood subfloor, then you can replace it with the same thickness of fir plywood, but you will have a stronger subfloor if you replace that plywood with BOARDS going across the joists. As long as the wood the boards are made of is the same as what your plywood was made of, or stronger, you'll have a stronger subfloor with boards across your joists than you will plywood.

If you choose to go with plywood, be aware that plywood is strongest in the direction of the grain of the OUTER plys. So, if you choose to replace your subfloor with plywood, make sure the plywood you put in has it's outer grains perpendicular to your floor joists. If you have to add a second layer of plywood to the first layer to build up your SUB-FLOOR to the thickness you want, I would paint white wood glue down to both mating surfaces before screwing them together for maximum strength.

That is, if you use plywood to make a thicker subfloor, glue both layers together, and make sure that both layers have their outer plies perpendicular to the floor joists.

Then, install your underlayment over your subfloor.


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## randallS1 (Sep 3, 2008)

*Gluing subfloor layers*

I have a problem that has appeared here before. i need to layer a subfloor to raise it's elevation. the subfloor is 3/4" OSB. I need to install 3/4" BC plywood. I was going to just screw it down but then saw a post here that said to use white glue between the sheets for maximum strength. can I do this when attaching 3/4 plywood to 3/4 OSB? Will the OSB swell from the water base glue? I am also not sure what size screws to use. Thinking of using #12 or #14 1-1/4 to 1-1/2.:wink:

The 2 x 10 floor oists are 16" OC and 3/4" x 4" White Oak plank flooring is going over the top of it all.

Any replies will be greatly appreciated.


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## Bud Cline (Mar 12, 2006)

QUESTION!

How is using glue going to give you more strength in a subfloor application such as this? 

The worst that could happen would be deflection between the floor joists and with those particular sizes you are using, deflection won't be an issue.

If you have overall deflection _of the floor joists_ then the glue is no help there either.

Typically the subfloor is glued to the joists to prevent squeaks and then fasteners are used. Then the underlayment you are installing is attached only to the subfloor and not the joists, and no glue is used. The joints are swapped away from the previous joints. This method tends to help isolate the underlayment from the structure and allows a slight lateral movement between the sheets when necessary. Use screws they won't squeak like nails will.


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