I'm going to replace my current fiberglass tub with a tile shower, and replace the particle board/laminate/Pergo flooring with tile. I need some help with the fine details before I finalize all my purchases and really get going with the demolition. There's pretty much one question per paragraph. I'll underline them for the sake of clarity.
My current sub-floor situation is 1/2" particle board (can be easily shredded with just a screwdriver) over 2"x6"s which are over the joists. The particle board must go, that's for certain. Can I replace it with 1/2" plywood, or would something thicker be needed? Also, is there a specific type of plywood that is better than others? Like birch vs. oak?
I am hoping to use Ditra as a substrate over the plywood. It seems like it would be the easiest for me to install, and it's thin, which is what I need if I don't want to have to modify my door. I'm clear on how to install it, modified thin-set under it and unmodified over it. However, the tile I ordered says to set it with either latex modified thin-set or epoxy. Is this a deal breaker for the Ditra? I've tried calling the manufacturer, but their phone system keeps hanging up on me. The tile is a 6"x6" glazed porcelain tile by American Olean in the Urban Tones collection.
I had a few contractors give me a bid for parts of this project with the understanding that we would be doing most of the work ourselves. Both of them said to put felt paper under the plywood, but that was when we were talking about using HardieBacker. Is this still necessary if I can use Ditra?
For the shower walls I've ordered DensShield, which is pre-waterproofed. Does anyone know if I have to seal around the screws as well as the joints when using this product? The installation brochure doesn't mention sealing around the screws, but it's kind of light on the details.
One more question. I'm installing a Tile Redi shower pan, and the installation instructions call for laying down a thin bed of mortar under the pan. Assuming that everything is properly supported, can I do this over Ditra? I've had a few people say yes, and a few people say no. Which is it?
Sounds like your setting yourself up for the perfect storm for a total disaster of a remodel.
I'll just touch on a few of the items and I'm sure some of the full time tile guys will be right behind me at some point.
2 X 6 floor joist are way under sized for floor joist. What's the spans and spacing?
A subfloor needs to be a minimum of 3/4" T & G.I only use Advantech for a subfloor.
It comes with a 50year warranty and will never delaminate like plywood.
It needs to be nailed with ring shank # 8 nails every 6" and construction adhesive on top of the joist.
No way would I use any drywall product like Densshield, you need real tile board.
It's remodeling 101 to cutoff the bottom of a door to allow air flow.
To clarify, the joists are not 2x6s. I don't know the size of the joists, because I haven't been under the house to look, but the 2x6s are laid flat ON TOP of the joists with about 1/4" in between.
DensShield is real tile board. This is directly from their product information page: "DensShield conforms to requirements of the 2009 IBC/IRC Code for tile backer in wet areas. It is the ideal ceramic tile underlayment for new construction, bathroom remodeling, pool areas, and many other high humidity or wet areas." DensShield is basically like using Kerdi, only it's already put together.
I can't see any reason to modify the door if I can just as easily keep the floor at the same level. I assure you that the door is not hermetically sealed in its current configuration.
We already know the particle board is junk and must be taken out. Use a 3/4" subfloor that is rated exposure 1.
I knew the 2 x 6 were the subfloor and not the joists. Joe just misunderstood cuz it's not a normal thing. If you had told us you lived on the left coast (am I right?), he would have caught that too. That's why we ask that ppl tell us where the heck you're located. :laughing: So, northern California, Oregon Wash State?
Ditra is a good plan. Install it exactly as you stated. Mod under, unmod to set all tiles. The porcelain tile manufacturer doesn't know you're going over Ditra. You gotta use mod for all applications except Ditra and Kerdi installs.
Felt under the subfloor may be a local thing. If you're where I think you are you probably have a crawl space that may get pretty damp. While we're talking about under the floor. Get under there and tell us what you see for framing. A few pics would be nice too.
Are your shower walls a stall shower or a tub enclosure? Makes a big difference. If a stall shower, I do not like to use DenShield cuz of the way they want you to do the bottom part. Have you studied their sketch?
You do not use Ditra inside a shower. Where did you read that? I do not use Tile Redi.
I am, indeed, a left-coaster. I'm in the damp half of Oregon.
As far as the felt paper goes, it was meant to be a vapor barrier. But it is my understanding that Ditra is a vapor barrier, so if I use both my worry would be that it would trap moisture in between and create a mold playground. There doesn't appear to be any kind of vapor barrier currently installed.
There is some confusion about my plan for the shower. I have already purchased the Tile Redi base. That ship has sailed. I read the thread of people having issues with it, but I saw a lot of people there installing it incorrectly and then complaining when there were issues. I hope to not be one of those people. I also hope the problem isn't in the base itself.
I would be putting the Ditra under the pan, not in the shower itself. So, the order of the floor in the shower would go substrate, plywood, Ditra, mortar, shower pan, tile.
As far as the DensShield in the shower is concerned, the Tile Redi base will act like a really short tub. The edges of the pan will be flush with the edge of the DensShield, both are completely vertical, and they will be sealed with silicone in between as per instructions. I have studied the DensShield installation instructions, and for my purposes it will be like I'm installing it in a tub enclosure. However, I'm still unclear on if I should seal the fasteners or not.
As far as the felt paper goes, it was meant to be a vapor barrier. But it is my understanding that Ditra is a vapor barrier, so if I use both my worry would be that it would trap moisture in between and create a mold playground.
That's correct. Ditra isn't exactly a good vapor barrier if the seems aren't sealed with Kerdi band (which is really easy, if that's what you want.) However I definitely wouldn't use Kerdi and tar paper together, as you said.
I would be putting the Ditra under the pan, not in the shower itself. So, the order of the floor in the shower would go substrate, plywood, Ditra, mortar, shower pan, tile.
Ditra is a waste of time under the shower pan. Ditra provides a layer between plywood and tile, because plywood is not a dimensionally stable substrate (i.e. it shrinks and expands.) Your pan isn't going to crack like tile might, so you don't need Ditra.
I just tried to link pictures, but I'm so new it won't let me until I've posted 5 times.
Anyway, I checked under the house and my joists are really far apart, between 5' to 6'. Not counting the perimeter of the house, there are only 4 of them. In a few more posts I can send a picture if it's needed. But it's basically just 2"x6" boards laid across joists that are about 5' to 6' apart.
As long as the particle board is in good shape, I would leave it in place and put 3/4" standard plywood right over the top of it. 1/2" total isn't enough support. This might bring up the level of your floor, but you're going to have to do it anyway.
High quality unmodified thinset is good over Ditra, regardless of what the tile manufacturer says.
Paper under the plywood isn't necessary with Ditra and tile.
I don't understand your question about your shower pan/mortar over Ditra. Ditra would not go in your shower area. Personally, I use Kerdi and the Schluter shower kit, so I can't comment on the Tile Redi.
That's very typical framing set up out there. It's not listed as an approved method in the TCNA Handbook, but we know of many floors covered with ceramic tiles built just like your.
Just gotta verify everything is well fastened and feels good.
Felt paper is not a vapor barrier, it's a vapor retarder. Ditra is not a vapor barrier in the true sense of what barriers do. The back of Ditra along with the interconnected channels actually allow moisture to escape and equalize. It does not keep it on the other side. However, if it's not a required thing, you shouldn't use it. Just make sure the crawl space is well ventilated, insulated and the ground has an appropriate barrier per local custom.
As for the Redi base, I think 99.9% of products work as advertised if installed and used correctly. My only contact with one was on a shower I did where one was installed before I got the job and was done wrong. The whole thing was bouncing like crazy. To the curb it went, and I did a Kerdi shower.
I guess I don't see any harm on installing Ditra on the floor under the pan. It's not necessary but...............
As long as the DenShield is not buried in the deck mud (which there isn't any here), it will be ok. If I recall the directions, it says not to apply a sealer over the fasteners unless the face is broken. It's a common thing that most ppl spot the heads and seams with liquid membrane though.
* Jeff misunderstood about the 2 x 6's too. I told you it's not common.:wink: That reminds me, once the particle board is out, you should go with 3/4" subfloor grade and not 1/2 ply.
Jeff, when I say that I need to put the base in mortar I mean a mud base, not thinset. That may have been the source of much of our confusion.
The instructions for the pan say, in bold, "Please note, do not place the mortar directly on a wood substrate," and I'm pretty sure it is to prevent the plywood from absorbing the moisture, as you said.
Ok, so I'm going to remove the particle board, replace it with 3/4" plywood rated exposure 1, then put modified thinset down under Ditra over the whole area. I will seal the seams with Kerdi-band using unmodified thinset (I was thinking of doing this anyway because I have destructive and water-loving offspring). I'll float the shower pan in a mud base, and install DensShield on the walls in the shower enclosure. I'll use some RedGard to go over the fasteners, because I also need to use some to cover the edges of the backer around shower niches.
For the order in which I install the tile, I was planning on starting on the walls around the shower niches, and going out from there. I will have some questions later about the best way to make the cuts around the shower head & stuff like that.
What kind of fasteners should I be using on the 3/4" plywood, and how far apart should they be?
Also, I'm not sure what to do about the baseboard. I got some matching 3"x12" bullnose tiles for the purpose. There is textured and painted drywall all the way to the floor, and I'm thinking that applying tile straight to it is a bad idea. Should I scrape off the texturing and apply the tile right to the drywall? I'm going to have RedGard anyway, so should I put it over the areas that will be receiving tile? What is normally done in this kind of situation?
Also, speaking of drywall coming down the floor, my new substrate will be higher than the old one. Do I need to cut the bottom of the drywall to fit the new plywood underneath the bottom edge, or can I just put the new plywood up to where the drywall starts and leave a little gap under the bottom of the drywall?
If going over 1/2" existing subfloor, use 1 1/4". If going directly over joists, use 2", driving directly into the joists.
Adhering tiles directly to the textured wall should be fine. Think ahead to how you will caulk or grout it.
As to your last question, I was with you until you said "gap under the bottom of the drywall". Do you mean your new subfloor will be 3/4" while your old one was 1/2", so now your floor is open to the crawlspace in that gap? If so, that gap should be filled with insulating foam or something to keep out bugs and drafts.
Jeff, my floor is not like what you're describing. I swear to you that my existing subfloor really is 2"x6"s laid 1/4" apart over joists that are spaced 5'-6' apart. There is, quite literally, only one joist that passes through my bathroom, and that is only in the narrowest section close to the door. There is no existing 1/2" subfloor, and there are no joists. Also, I thought attaching the plywood directly to the joists was a no-no in this kind of situation.
Yes, I meant that my new subfloor will be 1/4" higher and there will be a gap under the drywall. Insulating foam would not be a problem to get in there, so I'll just do that.
I understand what you're saying about the supporting mud under the Tile Redi. :thumbsup:
You should use 2" deck screws to install the 3/4" ply subfloor over your 2 x 6 subfloor. That means the 2" screws will bite 1 1/4" into the subfloor which is probably actually 1 1/2" thick. Be sure to gap the sheets 1/8" per normal. No glue is to be used. The new ply should be gapped 1/4" all around.
I don't think you'll need/should scrape the texture for the base moldings. It'l work as is. Grouting will be the same pain either way.
I've done some partial demolition to try get a clearer idea of what I'll need to buy for materials, and I've discovered that there was no waterproofing/vapor barrier of any kind behind my current tub setup. It was just the tub nailed directly to studs and plain drywall around it. So, it's not that shocking that there is some mold on the studs, though not as much as you might expect. Also, on the floor, there is some white discoloration on the 2"x6"s. (it can be seen a little in the picture above). I tried poking a screwdriver into the boards in several areas, and they seem sound. The whiteness scraped right off, but it was only about 1/32" thick.
Is there some product that I should put on the wood, either on the floor or studs? The studs framing the shower would fairly easy to replace, but the floor is a different story.
Obviously I meant to say that Jeff "hasn't dealt........." . above.
If the boards are not rotten, you can keep them.
The way your tub was tiled is pretty common cuz everybody wants to pay less money and in many cases there's no enforced standard for it. I recommend surface waterproofing, I use Kerdi or sometimes a liquid membrane.
OK, well it sounds like Jaz knows exactly what you're talking about with regard to your floor construction. Every time you say something that sounds somewhat familiar to me, I'm probably making wrong assumptions and getting you off track in that regard.
Regarding potential mold or fungus, if the wood is in good shape, usually you can just spray an anti-microbial made for that purpose on the wood, and then just get it dried out before continuing.
As I understand these forums, we're not supposed to start a new thread elsewhere to ask another question about the same project. I now have a backer to drywall transition question about this project, so I'll ask it here.
I'm using DensShield as my backer, and I just want to confirm that in DensShield to drywall transitions I should use tape and drywall joint compound on the joints. For joints under the tile, of course, I will use silicon and then tape and thinset like the instructions call for.
I was also thinking about my ceiling as I was prepping my existing drywall for the transition. It's currently normal textured and painted drywall with no vapor barrier of any kind. It occasionally gets spots of mildew which I get rid of with Tilex. Would it be worth it to replace the ceiling in the shower enclosure with textured and painted DensShield? Would it prevent future mildew growth on the ceiling, or would it still be able to grow in the texture and paint?
I don't see where the directions say to use silicone, but their instructions are very vague in many areas. I wouldn't want to bond anything over silicone caulk, it won't stick.
This must be where you got the idea.
GPdirections said:
* 2" (51 mm) fiberglass mesh tape–embed in a skim coat of
material used to set tiles on all joints and corners that are
to receive tile; caulk corners and edges prior to addition of
fiberglass mesh tape. Seal penetrations and abutments to
dissimilar materials.
For the ceiling; there's no insulation up there? There's rooms above?
I probably wouldn't install a backer esp if there will be no tiles. But it's not necessary even with tiles. There shouldn't be any direct water contact. So, no tiles? Use a paint made for this purpose. Perma White by Zinsser.
It is never a bad idea to use mold resistant products in your bathroom. However, if you find you actually have a strong need for them, then you should fix the problem. If water is literally splashing on the walls, then you probably didn't tile far high or wide enough. If behind a sink, put in a backsplash. If the bathroom is humid in general, then put in a fan. If there is a fan, use it. If it's not working right, check that the duct is open and unkinked all the way through the roof. If it's too weak, replace it. If there's water dribbling over the corner of the tub/shower, then pull the shower curtain tighter, and make sure all is well caulked along the wall and floor/tub line. etc.
Jaz, I was going off the instructions that you quoted. I assumed that it meant to sandwich some silicone between the joints, and not so much to spread it all over. If they mean to just do open spaces, like between the DensShield and the wall of the shower pan, then that's one step less. But the instructions are ambiguous. I took "corners and edges" to mean the joints. I watched the Flash instructions, and they don't mention caulking anywhere but between the bottom of the DensShield and top of the shower pan.
There is some fluffy insulation above the ceiling, but if there's no reason to replace the ceiling drywall, I won't do it.
It's entirely possible that the ceiling fan is inadequate, but I was going to wait to replace it. The mold issue is not huge. I spray a few spots every 3 months or so, so I wouldn't say it's out of control.
I'm pretty sure I never said to use silicone. Where did I say that?
Their instruction are vague, and I believe it's on purpose. There's other issues with the instructions and with Dens in a shower. That's one reason I don't use it.
Bleach products do not work very well on porous surfaces. Try Concrobium. http://www.concrobium.com/
Jaz
The shower floor is a Tile Redi pre-formed pre-sloped pan. You put a mortar bed down and shimmy the base into the mud. The pan has walls that are about 5" tall. I got the flashing system that you put over the edge of the walls and attach to the studs. From there you bring the backer down to 1/8" from the flashing and the instructions say to use 100% silicone in the gap, but not to get it all over. The part of this process that I'm most worried about is getting the drain done properly, but I think I'll have my contractor help me with that bit.
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