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Gizmo
Re: Plunge cutting tools

Sophie,
Nice looking tile. I wouild never install that tile without durarock on the subfloor. If you install durarock on top of the subfloor there will be to much deflection on the 2x6 floor joist.

The room isnt that big so why not be safe than sorry and dble the joist.

SophieC
Re: Plunge cutting tools

hey Gizmo....

I was not planning to leave out the durock. I just never mentioned it because right now, I'm just trying to understand what I need to know about the structural elements. Durock is not structural.

My plan is to put down a 3/4" thick sub-floor...
Followed by a 1/2" thick underlayment.....
Followed by the durock.....
Followed by the tile. :)

What exactly is the process of doubling the joists? What is needed? Just the joists and nails? Does this task require the house to be jacked up? I just don't know. Also, will I need to double the joists all the way to the center of the house, or can I stop the new joists once I pass the inside bathroom wall?

Gizmo
Re: Plunge cutting tools

hey Gizmo....

I was not planning to leave out the durock. I just never mentioned it because right now, I'm just trying to understand what I need to know about the structural elements. Durock is not structural.

By adding the durrock your adding additonal weight to the existing floor joist.

My plan is to put down a 3/4" thick sub-floor...
Followed by a 1/2" thick underlayment.....
Followed by the durock.....
Followed by the tile.

How are you going to handle the height difference from room to room or are you going to add the 1/2" underlayment in the entire house.. You already at 1 3/4" height without adding the tile.
What exactly is the process of doubling the joists? What is needed? Just the joists and nails? Does this task require the house to be jacked up? I just don't know. Also, will I need to double the joists all the way to the center of the house, or can I stop the new joists once I pass the inside bathroom wall?

[COLOR=blue]Joist & plenty of nails is fine,maybe even add construction adhesive between them before nailing. Nope you wont need to jack the house up. Depending on where your beam suports are in relationship to the bath room is where the joist will be added. Cut a joist to the desired length from beam support to support,then slip the joist next to the one your going to add to. Tip the top of the joist up and beat the bottom of the joist tight against the existing joist with a sledge hammer of heavy mallet. The joist will rol into position.
Its pretty easy especially if there are no mechanical supplies in the way.
__________________[/COLOR]

JLMCDANIEL
Re: Plunge cutting tools

Sophie, the movement of constant deflection will crumble the grout and can crack tiles. With the tile you plan to use cracked tile is less likely but crumbling grout is still a problem.
Jack

SophieC
Re: Plunge cutting tools
A. Spruce wrote:

That's my thinking as well, but why cut along this wall at all? With it only inches from the nearest joist like that (joist is on the bathroom side ), there's no need to remove the subfloor from that area.

The reason I am wanting to remove all the flooring in the bathroom is because I was told that you do not want strip flooring as your sub-floor if you are installing tile over it. :)

HoustonRemodeler wrote:

If you want to match the height of existing flooring or finish height is an issue will determine which course of action you take with the joist spacing - that will determine your thickness of plywood.

I'd cut out the center section, throw more double joists under those side walls and for the added few dollars and ease of access, add more joists on center between the old ones. Its a cheap, fast and easy way to super stiffen that floor.

If you do that, you can use 5/8" plywood with ditra and get the lowest profile under your tile.

The height difference is not really a huge issue for me. I will do what I can to keep it to a minimum, but in the end it is not a huge issue for me.

So if I double the joists under the 2 walls and add an additional ones between the existing ones, I should be OK for support, yes??!

What is this ditra? I've never heard of it? I know I can google it, but at the moment I am short on time. Maybe you can give me a little crash course on it.

Gizmo wrote:

[COLOR=blue]Joist & plenty of nails is fine,maybe even add construction adhesive between them before nailing. Nope you wont need to jack the house up. Depending on where your beam suports are in relationship to the bath room is where the joist will be added. Cut a joist to the desired length from beam support to support,then slip the joist next to the one your going to add to. Tip the top of the joist up and beat the bottom of the joist tight against the existing joist with a sledge hammer of heavy mallet. The joist will rol into position.
Its pretty easy especially if there are no mechanical supplies in the way.
[/COLOR]

So if I add additional joists, how long do they need to be. I've included a new image that shows a bigger picture. Would the joists need to be the same length of the originals....from outside wall to center wall? Or could I get away with ending them a couple feet beyond the bathroom wall? Now that I think about it, it would probably be best if they spanned the same distance as the originals, right?

JLMCDANIEL wrote:

Sophie, the movement of constant deflection will crumble the grout and can crack tiles. With the tile you plan to use cracked tile is less likely but crumbling grout is still a problem.
Jack

Jack, will crumbling grout still be a problem if I do what I mentioned above?!

Have you guys ever heard of Auroco? I called the lumber yard yesterday to inquire about the wood for my sub-floor. He asked what I was using it for and when I said a sub-floor under tile, he suggested that. He said it uses marine grade glue. I tried to look up some info on it, but couldn't find anything.

Gizmo
Re: Plunge cutting tools

I would span them like the originals exterior wall to beam support. Looks like 12 footers will do it, make sure you have at least 1 1/2" bearing on each end.

How is the center beam constructed? Beam size width/depth along with distance between support post & post size. Can you take a picture from below to post ?

Lets make sure your center beam is large enough to handle the additonal weight if the floor joist get doubled up.

FYI
Arauco.....

http://forums.iboats.com/showthread.php?t=304639&page=1

A. Spruce
Re: Plunge cutting tools
A. Spruce wrote:

That's my thinking as well, but why cut along this wall at all? With it only inches from the nearest joist like that (joist is on the bathroom side ), there's no need to remove the subfloor from that area.

SophieC wrote:

The reason I am wanting to remove all the flooring in the bathroom is because I was told that you do not want strip flooring as your sub-floor if you are installing tile over it. :)

That's the thing, though, with what looks to be 6 inches or less between the joist and the wall, you're not going to have any deflection in that area, particularly when you sister the joist. If it were me I wouldn't go to the extra work and hassles for absolutely no gain. The other side of the room is a different story, though similarly, I'd put a new joist in front of the wall and cut the flooring there rather than try to remove the subfloor from under the wall.

Gizmo
Re: Plunge cutting tools

[QUOTE=A. Spruce;, I'd put a new joist in front of the wall and cut the flooring there rather than try to remove the subfloor from under the wall.[/QUOTE]

Im with Spruce ...I mentioned pretty much the same thing above. Double a joist at the wall,let one of the joist sit directly under the wall the other one thats nail to it will stick out into the bath room to support your sheathing. With only one joist sitting under the wall 11/2" will support the wall and still leave you 2" just in case you have electric going i the wall that may need to be tied in below.......

A. Spruce
Re: Plunge cutting tools

Hey Giz, lay off the beer, you're repeating yourself ... ;):p:D

Gizmo
Re: Plunge cutting tools

What you talking about Willis ??? lol

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