Mud Bed Over Cleated Planks / Ply

[Crestone Tile]

Was there ever an installation guideline for mud beds over wood framing where planks are fastened over cleats between the floor joists? I'm guessing not but thought I would ask. Curious if there is a guideline / standard to do so in present day tile installation over old dimensional joist construction. I can't find one in ANSI and I'm guessing I won't since today's IRC does not have subfloor construction like the old ways.

The old mud floors around here and old Denver that I've seen / replaced consist of 3/4" planking cleated between the joist where the planking top surface is near flush to the top of the joist. The installations were followed by paper and nailed lath. The tiles were never cracked / debonded that I could tell ... just getting replaced because they were pink or some other old color. It's different than what I've seen in the Northeast where the mud actually sits between the bays with a trimmed / peaked joist along with lower planking.

Has anyone ever witnessed problems / failures with these types of installations? Why isn't there a current method for mud over planking whether in between joist or above joist for old construction? (Besides that setting materials manufacturers won't make money off of the method)

[bulldog tile]

Matt, we still do that type of installation here. It's especially used when more clearance is needed. I have used paper back lathe and mudded for years with no problem. Actually tore out a 20 year old installation of mine a few years back and it was in great shape. The 8 x 8 tile was a little out of date for the new homeowners.

[bulldog tile]

Some of the really older houses here have concrete between the joists with a 2" or more mud bed on top. When you tear up the mud bed it usually peels right off the concrete. The one in the picture was 70 years old and was in perfect condition but the new homeowners didn't like the black and white moasic.

[tilelayer]

Matt,

When I retiled my sister bathroom her floor was like that. I tore out mud, not a single crack. I decided to install a 3/4" plywood subfloor and then mud ontop of that. It didn't affect anything, I used a single bevel threshold at the doorway.

I choose to install the plywood because we tore a ton of the planks out when replumbing the area wasn't worth trying to patch.

[Crestone Tile]

Thanks guys. When I'm doing mud floors over wood, it's always done with fastened lath over paper or poly. The floors that I have run into where it's cleated planking, I've replaced the planks that need it, and mud it right back in. I've also done new mud jobs over typical plywood / OSB subfloor construction.

I've never "created" a cleated type mud job where there wasn't one previously, and I'm wondering if there is a reason why not to do it. I think it's the way to go over a lot of these dimensional lumber floors that are out of whack, and when there is a desire to maintain even transitions. I wish there was an ANSI / TCNA guideline to back up the method.

I have a 600' job I'm considering using the method on ... old house, particle board sheathing for subfloor that has to come out, joists not level / flat with each other.

[Old World Tile and Marble]

matt i answered this ? for you................


















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[tilelayer]

Matt,

Davy has a picture of a job where he cleated the floor and its a huge room. The only reason that its done is to keep the floor height down you loose the 3/4" gain you would have for the subfloor.

[Crestone Tile]

Yeah ... that's why I want to do it. To keep height down and gauge the mud to flush out the tile exactly to the neighboring wood flooring.

I guess my biggest question is why it's not a contractor's option in current TCNA or ANSI guidelines.

[tilelayer]

Cause its alot of work, you gotta sister every joist and cut out plywood to fit between each bay.

[Mountain Tile]

You could cut 3/4" off the top of the joists, then sister the joists, then plywood over the whole floor, then your mud.

[Dave Gobis]

It is not an option because nobody asked to keep it. It used to be a method and said something to the effect ledger strips were permissible with 1x lumber.

[Davy]

Here is the pic Rick was talking about.

[tilejoe]

Interesting this came up now. I was considering doing this to give a barrier free shower. I'll figure more out on monday

[John K]

I did one a couple years back and the carpenter lowered the plywood inserts alot more than I wanted. Anyway it took a boat load of mud for a simple master bath. and to me running the lath up and over the joists was a pain in the ass.

I could have added a solid plywood subfloor and used some backerboard and SLC and been finished in no time. Each situation is different, I know, but that was my experience.

[eurob]

Here is a very nice article about mortar bed installation by Dave Gobis.
It says a lot. Thank you Dave.

http://www.fcimag.com/Articles/Featu...00000000886864