We are replacing the flooring in our house. WE noticed some areas along an interior wall were sinking, and thought we needed to jack the house up. Had that done, didn't fix floor.

Pulled up a few pieces of the cheap laminate, and realized that the previous owners just put the laminate over top of the 100+ year old hardwoods that are terribly warped.

We are now being told we need to put a new subfloor down over the entire house.

Is this correct, or can we somehow just correct the problem areas?

I am no expert, but I thought this is what self-leveling compound is for, but as I type this - perhaps you can't put that stuff on hardwood flooring - it needs to be over a solid surface like concrete or plywood?

Someone I am sure can refute if incorrect...

In some areas, it's near an inch, which would be more in self leveling cement that subfloor

At least that's what we were told.

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I am no expert, but I thought this is what self-leveling compound is for, but as I type this - perhaps you can't put that stuff on hardwood flooring - it needs to be over a solid surface like concrete or plywood?

Someone I am sure can refute if incorrect...

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I don't believe SLC can be put over hardwood, it expands and contracts much more than plywood.

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We are replacing the flooring in our house. WE noticed some areas along an interior wall were sinking, and thought we needed to jack the house up. Had that done, didn't fix floor.

Pulled up a few pieces of the cheap laminate, and realized that the previous owners just put the laminate over top of the 100+ year old hardwoods that are terribly warped.

We are now being told we need to put a new subfloor down over the entire house.

Is this correct, or can we somehow just correct the problem areas?

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I'm confused about needing new subfloor... Is it attached to the joists or are there gaps? Is it otherwise damaged or rotten?

More than likely you need new subfloor, if you have particle board installed under the hardwoods you need to replace it. It also may be an issue of no vapor being installed under subfloor, of a failure of it all together. Just replaced mine at my home ( built in 69') and they put used plastic mulch and dirt bags under some areas.

If you do replace it, put a vapor barrier under plywood or a high grade osb (advantech) t/g.

The house was built in 1908, and these are original hardwoods. I can't imagine there being particle board or anything between them and the jousts, though I can see 1x6s (or 8s?) When looking up from the basement.


I would need a subfloor because there isn't one, and we cant/don't want to lay on warped hardwoods

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The house was built in 1908, and these are original hardwoods. I can't imagine there being particle board or anything between them and the jousts, though I can see 1x6s (or 8s?) When looking up from the basement.

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Probably 1X8 T&G or shiplap laid on the bias.

So I suppose there is no way to put subfloor only in some areas, and leave the areas that are fine?

TopNotch 350 is a good flooring that will not be overkill like advantech

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The house was built in 1908, and these are original hardwoods. I can't imagine there being particle board or anything between them and the jousts, though I can see 1x6s (or 8s?) When looking up from the basement.

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Probably 1X8 T&G or shiplap laid on the bias.

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Yep, and if it's undamaged it should be fine for installing new hardwood on. This still doesn't make sense to me...

We are not installing new hardwoods. We are putting carpet in our livingroom, and tiling the kitchen, dining,bathroom, and laundry room.

Ok now I'm starting to get it. For the tile my suggestion is t remove whatever hardwood may be problematic, then go back with a layer of 3/4" plywood on top of what you currently have. Then a layer of Ditra as a decoupling membrane and then you can tile. This is assuming your joists are good enough.

What's their unsupported span length, spacing and dimensions?

I bet those original hardwoods would look bad ass sanded and refinished

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Ok now I'm starting to get it. For the tile my suggestion is t remove whatever hardwood may be problematic, then go back with a layer of 3/4" plywood on top of what you currently have. Then a layer of Ditra as a decoupling membrane and then you can tile. This is assuming your joists are good enough.

What's their unsupported span length, spacing and dimensions?

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I don't know
They are roughly 12-15" apart
They appear to be maybe 2x8 or 10?

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I bet those original hardwoods would look bad ass sanded and refinished

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Maybe, but they would still be warped and bowed. We have the original hardwoods upstairs, and they look good, will just have to refinish them before we sell.

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Ok now I'm starting to get it. For the tile my suggestion is t remove whatever hardwood may be problematic, then go back with a layer of 3/4" plywood on top of what you currently have. Then a layer of Ditra as a decoupling membrane and then you can tile. This is assuming your joists are good enough.

What's their unsupported span length, spacing and dimensions?

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I don't know
They are roughly 12-15" apart
They appear to be maybe 2x8 or 10?

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You definitely want to know 100% for sure what the measurements are if you are planning on installing tile. If you have too much deflection the tile will crack. You should be able to find several good flooring deflection calculators/wizards online.

RTT is correct. You know to know these things for sure to know the tile won't self destruct.

They run 11 feet unsupported, then another 11 feet.
They are 14.4" apart
And are 2x8

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They run 11 feet unsupported, then another 11 feet.
They are 14.4" apart
And are 2x8

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http://www.johnbridge.com/vbulletin/deflecto.pl

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For joists that are SYP or Douglas Fir, in good condition, 7.25 inches tall, 1.5 inches wide, 16 inches on center, and 11 feet long between supports, the deflection calculated is 0.350 inches.

This translates to a deflection of L / 377.

Since the maximum deflection for tile is L / 360, and for natural stone is L / 720, your floor is rated for Ceramic tile, Congratulations!

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It's a good thing I bought ceramic tile

This is what we found under the laminate





This is our living room. It used to be 1 bedroom (in the back), and the living room for the downstairs apartment (was at one point a duplex, with one unit downstairs and one upstairs).

Interesting. It's a shame the stuff is warped, it would probably clean up otherwise.

It looks like you're in a colder climate? Is tile going to be a bit cold to walk around on in winter?