# laminate flooring on uneven sub floor?



## ponch37300

Anyone have any advice on self levelers or if laminate can by installed on a subfloor that is in some spots out of level about an inch in ten feet? Thanks


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## HomeDepot23

It should be 1/6" over 6ft per most manufacturers recommendations.


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## ponch37300

So is a self leveler my best option to fix this? Or is there other solutions? Thanks


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## HomeDepot23

I have always shied away from the self levellers. Mostly, because none of the installers I worked with used them, so I never really learned about them. I just mix my own floor patch and find my own level. So I really can't answer your question on self levelling. It may be easier, I don't know.


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## ponch37300

Does anyone have a recomendation on either a self leveler or a floor patch brand or product? I really don't have any experience with leveling floors. thanks


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## dalerdaler

*laminate floor on uneven subfloor*

I'm in a similar situation in my kitchen, and I'm really under the gun (the appliances and cabinets arrive this weekend).
I was told I could install the laminate over the existing linoleum floor, but I'm finding sags in 2-3 spots from water damage (a bad sink drain) from 15-20yrs ago.
The floor isn't ready to collapse by any means, but there is some minor rot and unevenness.
I thought I could perhaps add some additional padding under the laminate in the trouble areas...not so?


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## Guest

I'm assuming it's a wooden subfloor since it's an attic. The thing about a lot of your standard self leveling compounds is that you can't use them on wood without adding a layer of mesh to give it flexibility to cope with the different expansion properties of the wood. Most are designed mainly for concrete. There is a brand I know of that has fiberglass in the compound which forms it's own flexible mesh when you mix it up and pour it out. When I get to work today I'll look up the brand name and post it for you. This would be the easier way to go than having to deal with a seperate mesh. With self levelers you basically mix them up, pour them out and trowel them roughly into place. They finish leveling themselves after that. (note you have to use a primer on the floor first).


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## AtlanticWBConst.

*Do not use a leveling compound.* Consider using the standard leveling material for hardwood floors. Roofing shingles, layered like shims to level the areas.


Good Luck on your project.


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## Guest

The leveler I was talking about is Drytec 7600. You can use this for your application but like Atlantic said there are other options since it floats. It depends on how much gap you have to fill. Smaller gaps would be fine with layers of shimming material.


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## ponch37300

Atlantic, Thanks for your repley. Can you explain how to go about leveling with shingles. Just lay them on the sub floor and then lay the laminate over the shingles or do i need any kind of barrier? Can you smell the tar ever? Thanks


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## ponch37300

Does anyone know if i just lay the shingles on the sub floor to level it out or if i need to do anything else to the subfloor or shingles after they are leveled? Do these shingles leave a tar smell in the house after the laminate is installed? Thanks for your help with this.


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## AtlanticWBConst.

ponch37300 said:


> Does anyone know if i just lay the shingles on the sub floor to level it out or if i need to do anything else to the subfloor or shingles after they are leveled?...


Cut the shingles to the size pieces that you feel you need. Add layers, based on size, to slowly build up (step up) to the level required for each area. 



ponch37300 said:


> ...Do these shingles leave a tar smell in the house after the laminate is installed?


No, you will not have a tar smell. Example: Standard material placed under hard wood flooring is roofing felt (tar paper). There are no complaints from it. 

Good Luck with the project.


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## ponch37300

Thanks atlantic. Do i need to fasten the shingles down at all so they won't shift over time or just lay them on the sub floor and then lay the laminate over them. Thanks again guys


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## monitron

Hi.. I'm a newbie here to hijack this thread.  but I can definitely see becoming a regular on these boards, due to the amount of DIY trouble I get myself into...

I have a newly finished basement where I'm planning to install laminate flooring. The floor is bare concrete right now. While mostly flat, it does have a high area and the slope up to it is pretty harsh -- almost an inch over four feet. The general contractor I'm working with says that if I install the planks perpendicular to this "hill," it should "bridge the gap" and produce a good result. I'm a bit skeptical... but I'd appreciate knowing what you folks think.

Am I also a candidate for shingles? It'd be great to be able to use some of these to even out this slope... I REALLY don't want to pour an inch of self-leveling compound over about 500 sq ft! If shingles are good, do they go under the underlayment? And to echo the previous question, do I need to attach it to the floor? 

And if shingles don't work, are there any other possibilities? 

Thanks so much 
Justin


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## AtlanticWBConst.

ponch37300 said:


> Thanks atlantic. Do i need to fasten the shingles down at all so they won't shift over time or just lay them on the sub floor and then lay the laminate over them. Thanks again guys


No, you do not need to fasten them down, they will not move at all.


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## monitron

Hi Atlantic and other flooring gurus --

I hate to bump, but I'm getting ready to start on my laminate job and hoped you could just give me a quick thumbs up or down on whether the shingle solution would work on concrete... and are there any special considerations?

I've done my searching and I can only find it recommended to folks installing over wood subfloors. Will it work for me too, or must I seek another solution?

Thanks much 
Justin


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## doitrighttim

tar paper i hear this allot I have a similar problem with an area of a floor im working on i need to bring it up a little so I'm going to use tar paper


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## scorp

don't mean to hijack this thread but i have a question pertaining to laminate install on uneven floor my house is approx. 100 yrs old and it has sagged over a concrete wall in my basement... now i read i can use shingles to bring up low points... but what about high points? i need to get the high point down or i will be left with a step where i meet ceramic tile....

floor planer be the best way?


i would say over 4' its probably out 1/2 - 3/4 out


any ideas would be appreciated and thx in advance


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## Floorwizard

you have to grind the high spots for sure.
Not sure which tool is best but others will chime in.


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## ponch37300

I would recommend being careful grinding down your subfloor. It is a high spot because the support is underneith the high spot and if you grind 1/2 to 3/4 of an inch off your subfloor there will be no strength left. Just something to think about.


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## scorp

ponch37300 said:


> I would recommend being careful grinding down your subfloor. It is a high spot because the support is underneith the high spot and if you grind 1/2 to 3/4 of an inch off your subfloor there will be no strength left. Just something to think about.



actually it isn't a sub floor... its the existing hardwood on top which is 3/4 thick and then i have subfloor below that which is also 3/4 thick..... i think i should be ok but any more input would be great..


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## ponch37300

I see. Maybe a belt sander or another option if it's 3/4" out of level in 4' would be to rip that 4 feet of hardwood out and then use shims to level it.


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## scorp

ponch37300 said:


> I see. Maybe a belt sander or another option if it's 3/4" out of level in 4' would be to rip that 4 feet of hardwood out and then use shims to level it.


now that sounds like a plan !!!
i thought about that and that would seem to be the easiest way to go...thx peeps :jester:


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## SurfnSun1176

*Late To The Party*

I see that this thread's last activity was in 2008, but I'm dealing with the same exact thing as these other gentlemen in this post (high spot in floor). I am using Blue Hawk 1/8" Underlayment from Lowe's in the hallway leading to our master bedroom (relatively small area), and so-far-so-good. I am using the same method that someone referred to with using shingles (stacking method) to build up the low spots.

My main problem is in our great room (living room and dining room combined) where I have a pretty good-sized high spot a little past the half way point. The most recent post was referring to cutting out the sub floor so that it's not a high spot anymore and then using shims, shingles (or underlayment in my case) to bridge the gap. I think I would much rather do this than to try to sand the sub floor to the extent that it would need to be sanded.

Any other options? Any draw backs to uninstalling the subflooring?


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## TheJerk

SurfnSun1176 said:


> I see that this thread's last activity was in 2008, but I'm dealing with the same exact thing as these other gentlemen in this post (high spot in floor). I am using Blue Hawk 1/8" Underlayment from Lowe's in the hallway leading to our master bedroom (relatively small area), and so-far-so-good. I am using the same method that someone referred to with using shingles (stacking method) to build up the low spots.
> 
> My main problem is in our great room (living room and dining room combined) where I have a pretty good-sized high spot a little past the half way point. The most recent post was referring to cutting out the sub floor so that it's not a high spot anymore and then using shims, shingles (or underlayment in my case) to bridge the gap. I think I would much rather do this than to try to sand the sub floor to the extent that it would need to be sanded.
> 
> Any other options? Any draw backs to uninstalling the subflooring?


1. If you remove the sub-floor you have open floor joists, meaning a hole in your floor. Then you have to install a new sub-floor and when you do you'll have the same high spot unless you fix it, as it's the joists underneath the sub-floor sagging, twisting or rising that is causing your issue. Measure where your high and low spots are and then go under the home and check the joists to see why your floor is uneven.

2. I have an 80 year old home and had a similiar issue with it. After inspecting the joists I discovered my high spot was cause by a single floor joist that had slightly twisted (warped) over the past 80 years. 2 possible solutions to this: Place a support between it and the joist it is warped towards and hope to drive it back to it's correct spot and run the risk of shifting the joist I'll be pushing against. Or find a way to work with it.

I chose option 2 as it does not run the risk of communicating further damage to other parts of the home. In my case I cut out the hardwood floor and sub-floor 32" x 42 " section that was affected. I then cut 2 x 4's into 32" lengths and ran them perpendicular to the joists over top the old ones. As I crossed each joist I marked how high it was at that spot vs. the actual flooring and then notched them on a table saw. 

Notching is very easy to do on a table saw, just set the blade to the desired height and then send the 2 x 4 over it for the section that needs notched. 

After each 2 x 4 was notched I had a very flat and level floor that was ready to receive it's new flooring. Keep in mind, you want to lay the 2 x 4 across the joists so it is only 1 1/2 " high as this will reduce the amount of notching you need to do. In my case I did 12 2 x 4's and covered the entire area screwing them to each floor joist.


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