Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Ceramic Tile Advice Forums - John Bridge Ceramic Tile (https://www.johnbridge.com/vbulletin/index.php)
-   Tile Forum/Advice Board (https://www.johnbridge.com/vbulletin/forumdisplay.php?f=1)
-   -   Old House Reno: Two Bathrooms, Many Problems to Solve (https://www.johnbridge.com/vbulletin/showthread.php?t=130200)

MesaTileworks 12-09-2020 11:15 AM

Old House Reno: Two Bathrooms, Many Problems to Solve
 
The missus and I bought a fixer-upper and are doing a bunch of renovations prior to moving in. Both bathrooms have been completely gutted so we have a blank slate. Old house.. almost nothing plumb or level. [emoji41]

First retrofitting question to arise is the floor in the small downstairs bathroom. Planning on making a mud pan for the shower and waterproofing with Kerdi. Floor outside the shower will be small hex tile.

The current subfloor slopes considerably—about 1.75” over 6’ and I’m weighing options for leveling it and trying to decide whether to remove the existing subfloor and sister-in new joists, or put down an additional layer of plywood and then pour a self-leveling compound. The floor joists are 2x8s, 16” OC—old framing so they are true 2x8s. The current subfloor is the original 1” floorboards.

What are the pros and cons of self-leveler vs. ripping up the old floor? Laticrete NXT level or something similar is attractive if it saves us time putting in new joists, but if there are compelling reasons to start fresh, I’m all ears.

Big gratitude to the folks on this site for taking the time to answers the many questions of us mere mortals! [emoji6]

https://uploads.tapatalk-cdn.com/202...04f24ded7d.jpg

condo-owner 12-09-2020 11:38 AM

old house = nothing level/plumb = i know the feeling.

if the 1.75 is even across = rip some 2x = 1/2", 1", 1 1/2", 1 3/4". fasten them down, then plywood.

john619 12-09-2020 12:59 PM

If you have a foundation repair contractor come in and re level the house to start would be the best bet. maybe add a few posts and shim others to get it pretty close. More expensive but a way better solution prior to undergoing a renovation. We re leveled again after 25 years in the areas we were going to remodel. It makes everything way easier in the long run and the house is stabilized.

MesaTileworks 12-09-2020 01:11 PM

Re: leveling the foundation, we actually have a contractor doing a bunch of work on that front. The 1.75” is as good as its going to get in this area of the house for various reasons.

As far as ripping shims (and did you mean putting them on top of the existing subfloor planks and then putting down new ply on top?) this is as an idea my father in law floated, but I was concerned that this wouldn’t provide a rigid enough surface, even with Durock over the plywood?

cx 12-09-2020 01:45 PM

Quote:

Originally Posted by Matt
The floor joists are 2x8s, 16” OC—old framing so they are true 2x8s.

Without an unsupported span, Matt, that doesn't tell you what you need to know.

I would advise against the shims and would advise sistering with some 2x6 to flatten and level the floor. Your tiles don't care at all about level, only about flat. If you want the floor level, that's a different matter.

My opinion; worth price charged.

MesaTileworks 12-09-2020 01:50 PM

Thanks CX, is a self-leveling compound not an advisable application for this kind of situation?

If I go the new-joist route and put 3/4” ply on the joists and then Durock, is that sufficient subfloor?

I’m not sure of the span. I can measure it and take some photos if need be.

condo-owner 12-09-2020 01:58 PM

Quote:

Originally Posted by MesaTileworks (Post 1554363)

As far as ripping shims (and did you mean putting them on top of the existing subfloor planks and then putting down new ply on top?) this is as an idea my father in law floated, but I was concerned that this wouldn’t provide a rigid enough surface, even with Durock over the plywood?

yes, most ideally on top of joists. you can put the shims every 6" and make it solid as a rock.

if you decide to go this route, i have a super easy way to make them flat and level.

cx 12-09-2020 02:03 PM

The unsupported joist span will tell you weather you need the sisters to provide strength or just to level and bring the joist tops into plane.

You can use the SLC if you want, but that's a lot of additional dead weight and expense. And that makes knowing the joist structure even more important.

If you'll download and read the installation instructions from the Durock website I think you'll find that exceeds the manufacturer's minimum requirements for subflooring.

My opinion; worth price charged.

MesaTileworks 12-09-2020 07:12 PM

Quote:

Originally Posted by condo-owner (Post 1554368)
yes, most ideally on top of joists.

I suppose I could put a ripped piece over top of each joist and ad one in between each for extra support. What do y’all think the pros and cons are of doing this vs taking up the subfloor and adding joists?

Handy Heather 12-09-2020 08:08 PM

1 Attachment(s)
If the subfloor is not rotten, the best advice is to not touch it. Even if the house is not level it is happy the way it is and the subfloor is part of it. If the floor is sloped from the bathroom entrance the fix is very easy. I deal with that all the time and I use the 1/4" Hardiebacker sandwich. You gradually build until everything is in level and in the end cover it with a final layer of Hardiebacker. The sandwich is much better than any leveling compound. The leveling compound could crack due to an unstable foundation. If the house is already settled then it's important to also look and see if the foundation needs any waterproofing for stabilization.
In my picture, you can see the way we build a curbless walk-in shower that needs a lower subfloor for the shower slope. In this case, we already had the slope because the house was unlevel so we simply leveled the rest of the bathroom around it.

condo-owner 12-09-2020 08:20 PM

Quote:

Originally Posted by MesaTileworks (Post 1554392)
I suppose I could put a ripped piece over top of each joist and ad one in between each for extra support. What do y’all think the pros and cons are of doing this vs taking up the subfloor and adding joists?

how about a pic of the room ....

cx 12-11-2020 12:44 PM

Quote:

Originally Posted by Heather
I deal with that all the time and I use the 1/4" Hardiebacker sandwich. You gradually build until everything is in level and in the end cover it with a final layer of Hardiebacker.

And just how do you make this "sandwich," Heather? Specifically, how do you fasten the various layers to the subfloor per the Hardiebacker installation instructions?

MesaTileworks 12-11-2020 01:34 PM

To answer the earlier question about the joist span, for this section of the house where the bathroom is, it’s 14’.

I plugged the numbers into the deflecolator and it says

“For joists that are SYP or Douglas Fir, in good condition, 8 inches tall, 2 inches wide, 16 inches on center, and 14 feet long between supports, the deflection calculated is 0.484 inches. This translates to a deflection of L / 347. Since the maximum deflection for tile is L / 360, and for natural stone is L / 720, your floor is rated for Sheet Vinyl or wood.”

So, I guess this means I have a problem beyond just getting the floor flat and level. I need to take a look and see if sistering in additional joists is still an option (the plumbers have been at work down there and it’s not as easy-access as it was, unfortunately).

I’m assuming that joists that get sistered in in this situation need to run the entire length of the span (not just under the area that will be tiled) to be effective? There’s a chimney and other obstructions that I need to deal with.

Yeesh. I’m flummoxed but open to suggestions.

The bathroom is over the area circled in the photo below. Basically behind the brick chimney shown in the first photo.

https://uploads.tapatalk-cdn.com/202...84c5f348e9.jpg


https://uploads.tapatalk-cdn.com/202...a703e8dfcd.jpg


https://uploads.tapatalk-cdn.com/202...5089123bfe.jpg

Kman 12-11-2020 02:32 PM

You'd need to sister 2/3 of the span to cut thee deflection, so you'll need a 10' 2x for that.

It should be glued and screwed to the joists to make it effective.

Or you could shorten the span a few feet as an alternative.

cx 12-11-2020 03:24 PM

And that must be at least the center two-thirds of the span, Matt.

My opinion; worth price charged.


All times are GMT -6. The time now is 10:56 AM.

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC