Floor out of level

[b_m_hart]

I'm working on preparing a floor for tiling, and it is horribly out of level.  There is a bit of a crown in the middle, and then it slopes down toward the back of the house.  It looks like some solid settling has taken place after two major earthquakes, which isn't too surprising to me.

So, anyone out there have experience leveling a floor in preparation for new hardwood or tile?  To describe how the floor is, it is roughly level from the room next to it as you walk in, then it dips roughly a half an inch.  Then it rises up into a bit of a crown (about 3/4"), then drops off about an inch total at the end of the room (so about 3/4" down from the far end of the room).

 

[monte]

b/m

I had exactly the same issue a few years back on an upstairs bedroom in the L.A. area.

The floor I worked on was spread over two rooms and the extreme difference  was almost a ski run at an 1 1/2"

Think "subfloor" below the hardwood your going to put down.

First, redo your bid and think about doing the following......

Laying angled cut fir strips to compensate for the dips.

The angled cuts need to be, so that the top of the strips are level.

I made my cuts off the short end of a 2" by 12",

if you place side to side a couple of 2 by 12's over a sawhorse....you could set your rails,

and with the TS55 whack off your strips.

Do this to the two sides of the room, then lay a wooden straight edge across the room....sitting on those two strips.

You will then see the cuts you'll have to make to fill the middle, I did it so the strips were 12" apart.

Check level across all strips, then lay down 3/4 inch flooring ply over that.

Putting down chalk lines over the ply so your screws are going to go through the strip below.

Personally, I would screw the ply down as to prevent creaking.

Walk all over it to check for creaking.

Lay down your hardwood floor over that.

That's how we do it in LA, now Per could have a "Jersey" fix that may be different.

hope that helps,

Roger

ps. there is that issue about the segue from the other room, but without plans or photos this is the best I could do for now.

 

[b_m_hart]

I don't think there will be issues with the segue from the other room, as we're putting new tile in both rooms.  Given the cool and damp nature of San Francisco, we plan to pull the existing particle board subfloor, and put down something that's a bit more "tile appropriate" so it will minimize potential for it to swell or distort.

The angled slips seem like a good idea.  Once we've got the subflooring up it will be a bit easier to see the extent of the issue.

 

[Eli]

There's a PDF on JLC that deals with this installation. You'll have to screed out a flat surface, unless you are going to level the new subfloor pre-installation by sistering the joists.

 

[b_m_hart]

There's a PDF on JLC that deals with this installation. You'll have to screed out a flat surface, unless you are going to level the new subfloor pre-installation by sistering the joists.

JLC?

 

[danrush]

If you are pulling the subfloor anyway...  What I have done in the past is just sister some 2x lumber to the existing.  It doesn't have to be the same dimension as the existing floor joists, 2x4, or 2x6 should suffice.  I would glue and screw to the new level, and then install the new subfloor. Just a thought from a former remodeler.

 

[b_m_hart]

One other thing I see is that it's recommended to put down a cement backer board before installing floor tiles.  My understanding is that this helps prevent moisture from getting to the sub flooring, and causing it to swell or distort.  Is that so?  Does the age of the wood matter?

 

[jaegerhund]

Yeah the cement backer boards are "seamed" with fiberglass tape and mortar, usually giving a bit of water resistance --- and a nice surface for the tiles to adhere to --- you could always float a mortar bed if you feel adventurous  . 

Justin

 

[b_m_hart]

Here's a pic of what I'm talking about:

http://b.m.hart1.googlepages.com/IMG_0222.JPG/IMG_0222-full.JPG

(sorry, no low res version that I can embed here)

You can see the slope to the left, relative to the drywall (third coat goes on tonight, joy of joys)...

 

[Eli]

There's a PDF on JLC that deals with this installation. You'll have to screed out a flat surface, unless you are going to level the new subfloor pre-installation by sistering the joists.

JLC?

sorry, different time zone. Journal of Light Construction. A subscription is like having thirty cranky old rich contractors telling you the right way it's all done.

All right, that's an exagerration. About two of them are pretty well off, and five other ones had just finished paying off the new F-350 before gas started to go up.

 

[Cannuck]

There are three approaches to levelling the floor that I would propose, if you are planning on tiling.

The best method, IMHO, is to sister the joists.  If you are in an earthquake zone, than you probably need to use approved bolts (not nails or screws).  I

Given the crowning in the middle of the floor, this method might be better suited to your situation.  The easier method, is to use a self-levelling cement.  If you are on a wood subfloor, you will need to use a primer first, to prevent the subfloor from being damaged - and to increase adhesion.  Before you pour the self-leveller, screw the sub-floor down at 3 inch centres on the joists.  Scribe a level line around the perimeter of the room - level (or 1/2 inch below) your threshold, and do your pour.  The self-leveller is amazing - just oozes out to the edges and gives you a reasonably level surface to tile.

Lastly, you could lay a dry mortar bed.  This creates a thicker subfloor though, and probably won't work well with tying into the adjacent rooms.

Whichever solution you use to level the subfloor, I highly recommend you put a substrate down for the tile.  Cement backer board is ok.  I would recommend you use Schulter Ditra membrane.  I tend to use Ditra whenever I tile.  Sometimes in the older Victorian houses, where there the floors are really out of level, I will do a dry mortar bed.  For dry mortar bed, you don't need a substrate.

Either substrate will absorb the movement of the subfloor from the tile floor.  The result is that you have less chance of getting cracks in the tiles or mortar due to subfloor movement (or earthquakes).

Good luck.

 

[Cannuck]

Oh, one last thing.

You may want to put an expansion joint at the threshold between the two rooms, if you are continuing with the tile throughout.  I only mention this because your re-levelling of subfloor in the one room may create different rates of expansion/contraction between the two rooms.  A situation that is bound to create a crack over time.

Alternately, create a seamless joint of Ditra membrane or cement board through all rooms.

 

[Michael Kellough]

15 years ago I tiled a bathroom in my old low end Victorian house that was pitched a lot in one direction and a little in the other.

I made a grid/screed of tapered 1x strips so that it was level in all directions (would have been a lot easier with the Festool stuff) and filled the thing with mortar. Over that I embedded something similar to the Ditra (another German company?) and the tile on top.

Actually, the supplier I bought the stuff from now carries only the Ditra stuff. While the name may have changed (?) the principle (even the color) are the same, and like Festool, there is a well thought out system involved. Another benefit of the Ditra membrane is that it makes changing the tile in the future much easier.

Designed specifically for ceramic tile and dimension stone installations, Schluter-DITRA serves as an uncoupling layer, waterproofing membrane, and vapor management layer that accommodates moisture from beneath the tile covering. Further, DITRA performs all these functions while still providing adequate support/load distribution for the tile covering.

It was one of the best last minute decisions I've made, spurred by the realization that the "baseboard-like" tiles I planned to put around the bottom of the wall wouldn't work unless the floor was square to the wall, as in level.

 

[monte]

Thank you Cannuck and Michael for the Ditra info input.

One comment though, it's been mentioned several times about floating mortar to level the floor.

(Michael, I like what you said about leveling mortar between the strips)

but...... I do have one question in regards to these aged buildings that these remedies are being applied/suggested,

that is depending on the slope that needs to be filled in,

all the added weight of this mortar has not been addressed in any of these posts.

As to the condition of the substructure below and the longtime effect of all this added weight will have over time,

in a structure that is already tweaking because of geological changes.

Keep in mind this is coming from a furniture maker/sculptor that sometimes

ventures beyond my own perview.

Roger

 

[Michael Kellough]

Roger, in my floor the deepest fill was about 1.5 inches so the extra load from the mortar fill was maybe 25# per sq. ft. But, this was only added to floor area covered with tile in a bathroom so there isn't much partying going on and there is usually only one person in there at a time so I don't think it's a real concern. Also, in my case, since the house is over 100 years old the settling more or less ceased a long time ago. No recent earthquakes in the NYC area.

I did have to make a compound tapered sloped threshold to transition to the unleveled hall floor.

 

[b_m_hart]

OK, so one point of clarification from my end - I don't know if I'm using the proper terminology.  Currently, there are vinyl (linoleum?) floors in my kitchen and back room where I intend to do this work.  Below that is a 1/2" sheet of particle board that looks to have been put there as "new subflooring" back when the linoleum was put in.  It rests on top of old floor boards that rest on top of the joists.

So, doing a sister joist would be horribly painful for me right about now, as I'd have to pull up WAY more wood than I'm interested in.  I believe that I will want / need to level the floor up from what was the original floor boards and then put a level subfloor on top of whatever is done to level things (the tile, of course).

So the Schluter stuff is used in lieu of backer board?  It seems like a pretty good product.  A bit pricier than backer board, but looks FAR easier to work with, and offers some dimensional flexibility that backer board wouldn't - which is nice in a place like San Francisco.

 

[Michael Kellough]

OK, so one point of clarification from my end - I don't know if I'm using the proper terminology.  Currently, there are vinyl (linoleum?) floors in my kitchen and back room where I intend to do this work.  Below that is a 1/2" sheet of particle board that looks to have been put there as "new subflooring" back when the linoleum was put in.  It rests on top of old floor boards that rest on top of the joists.

So, doing a sister joist would be horribly painful for me right about now, as I'd have to pull up WAY more wood than I'm interested in.  I believe that I will want / need to level the floor up from what was the original floor boards and then put a level subfloor on top of whatever is done to level things (the tile, of course).

So the Schluter stuff is used in lieu of backer board?  It seems like a pretty good product.  A bit pricier than backer board, but looks FAR easier to work with, and offers some dimensional flexibility that backer board wouldn't - which is nice in a place like San Francisco.

I have no idea which would be better in the event of earthquake, cement board or Ditra.

That "1/2" sheet of particle board" was probably installed as underlayment rather than new subfloor to provide a smooth surface for the flexible flooring. The joints in old floor boards would telegraph through.

Your description of the floor, "To describe how the floor is, it is roughly level from the room next to it as you walk in, then it dips roughly a half an inch.  Then it rises up into a bit of a crown (about 3/4"), then drops off about an inch total at the end of the room (so about 3/4" down from the far end of the room)." suggests that you might be able to judiciously remove some of the 1/2" particle board in the center, add a layer at the far end, and maybe a bit of a thinner piece to the dip then feather the edges by sanding and adding patching compound where needed. Instal Ditra and tile and the finished surface will be about the same height as the present crown.

 

[Cannuck]

So, doing a sister joist would be horribly painful for me right about now, as I'd have to pull up WAY more wood than I'm interested in.  I believe that I will want / need to level the floor up from what was the original floor boards and then put a level subfloor on top of whatever is done to level things (the tile, of course).

So the Schluter stuff is used in lieu of backer board?  It seems like a pretty good product.  A bit pricier than backer board, but looks FAR easier to work with, and offers some dimensional flexibility that backer board wouldn't - which is nice in a place like San Francisco.

I didn't mention in my previous reply that when sistering joists, you'll often encounter other detail problems.  Usually the interior partition walls are built on top of the subfloor (old planks in your case).  When you're removing the sub-floor to sister the joists in only one room, you often encounter issues of the interior partitions interrupting the continuity of the sistered joists.  Furthermore, alot of planked subfloors are installed on the bias (45 degrees) - meaning that you'll often have no bearing points on some of the boards (they'll be cut in half).

I would definitely go with the self-levelling mortar.  Michael's idea of furring strips is a nice touch too.  I am confident the added weight is negligible - probably not much more than 3/4" plywood to be truthful.

As for Ditra versus Cement underlayment - I would go with Ditra if you don't mind the extra cost.  I live in Ottawa, on a fault line (nowhere near what California is).  Any tiling I've done with Ditra, I haven't regretted.  I believe it provides better dimensional stability than cement board.  Also in bathrooms and laundry room applications, you can tape  the seams and wall edges, to get a continuous water-proof membrane.

It also provides a cushioning affect.  You won't believe it until you walk on it.  It absorbs your steps a minute amount.

 

[Per Swenson]

You guys are going to think a lot less of me when you hear this.

But yeah, I do this all the time for customers and yes we have done

countless bathrooms in our career. All though none in a earth quake zone.

This job  requires three things and one day. Less time then it took to write this thread.

First, Level quick,

second, Thin set, the first one here

the multimax. Different companys make the same stuff.

Use this to glue down either 1/4 or 1/2 wonderboard level.

One day job, Tile it the next.

Go ahead, say hackery, but that slab won't go anywhere.

Per

After rereading that wasn't explicit enough.

Pour the level quick get it close.

It sets in a hour, two at the most.

glue your wonderboard as if you were setting very large tile. Actually you are. Nice and level.

That reads better.

P.

 

[monte]

You guys are going to think a lot less of me when you hear this.

But yeah, I do this all the time for customers and yes we have done

countless bathrooms in our career. All though none in a earth quake zone.

This job  requires three things and one day. Less time then it took to write this thread.

First, Level quick,

second, Thin set, the first one here

the multimax. Different companys make the same stuff.

Use this to glue down either 1/4 or 1/2 wonderboard level.

One day job, Tile it the next.

Go ahead, say hackery, but that slab won't go anywhere.

Per

After rereading that wasn't explicit enough.

Pour the level quick get it close.

It sets in a hour, two at the most.

glue your wonderboard as if you were setting very large tile. Actually you are. Nice and level.

That reads better.

P.

b/m,

See........I told you 17 posts ago that Per would have a "Jersey Fix"

R.