Bathroom Renovation

[MelodyJoy]

Hi everyone! Renovating a 1961 bungalow and am looking for some advise about the subfloor please. The room I am working in is currently a bedroom but is going to become the new master bathroom. The demolition is complete and after scraping off the old vinyl type floor tiles there is a thin layer of felt like substance stuck to the subfloors and it is not coming off. The subfloor is 5/8" TG plywood running perpendicular to the 2X10 Douglas Fir floor joists which are 16" OC and the joist span is 12.5'. I used the deflecto tool and got a thumbs up for ceramic tiles.
1- I believe I need to increase the thickness by adding another layer of plywood to the existing subfloor to accommodate the weight of ceramic tiles. What thickness should I use?
2- Does all the "felt" like material need to be scraped completely off the existing subfloor before installing the new plywood on top of it or can I just make it really level and screw it on?

Thank you in advance for your assistance!

[Lazarus]

If it doesn't bulge up really high, I would think you could attach the new plywood over it. Having said that, can you use a 4" razor scraper to get it really close down to the old plywood? If you can, do it.

[MelodyJoy]

I have a scarping attachment for the sawzall and using it right now. It is taking up a lot of it thankfully. I was concerned if I had to glue the new plywood to the old subfloor it wouldn't bond but if I can just screw them together that will help a lot!

[PC7060]

Hey Melody, welcome to the forum and happy holiday!

Have you verified the vinyl was laid directly over the plywood subfloor? Usually it's installed over 1/4 luan plywood which will need to come up too. Forgive me if I missed this info in your original post.

[Lazarus]

He's right, Melody. ANY 1/4" plywood is generally a "No-No" to tile over. It really needs to be ripped out as it will swell when exposed to damp thinset and absolutely ruin your tile job. 1/4" is the only plywood that exhibits this problem.

If it's there, get it out!

[PC7060]

Hey Laz, cool tag line

[MelodyJoy]

Thank you Laz and PC. I double checked and there is no 1/4" plywood on the subfloor. So for the plywood I add to the 5/8" subfloor, would 3/8" TG be sufficient?

[cx]

Welcome, Melody.

I would recommend nothing less than nominal 1/2" exterior glue plywood for you second layer even though 3/8ths" is technically the minimum.

My opinion; worth price charged.

[MelodyJoy]

Thank you CX.. will go with the 1/2 inch T/G exterior glue plywood. I have been doing some online pre-shopping and can not find anything better than a C grade or in many cases grades are not mentioned. Is that good enough or should I wait until actual lumber stores are open on Tuesday?

[cx]

Any grade of C or better is fine.

You do not need T&G for your second layer of subflooring. This is a good thing as you will not find half-inch material in a T&G style.

My opinion; worth price charged.

[MelodyJoy]

Excellent! Thank you for the correction! Would this do the trick?

Taiga Building Products 1/2 x 4 x 8 Spruce Sheathing Plywood

•Moisture and Swell Resistant
•Plywood is a highly impact-resistant panel and continues to perform even when wet
•Barrier/House Wrap Applied: No
•Environmental Certification: CSA
•Glue Type: Exterior
•Nominal Thickness in Inches: 1/2
•Panel Grade: C-C
•Plywood Type: Sheathing
•Pre-Cut: Yes
•Printed Nailing Pattern: No
•Species: Spruce
•Struct 1: No
•Type of Pressure Treatment: Untreated
•Warranty: Subject to normal construction environment
•Weather Exposure: Exterior

[MelodyJoy]

Good evening.. Just wondering if anyone has a picture of rough shower framing that I could look at to make sure I have the right idea. The shower I have to frame is rectangular, dimensions 36" x 48", I am going to try the mud deck and use kerdi membrane for waterproofing. I found this on Google is it how you guys do it?

[cx]

Melody, residential wood framing is a pretty straight forward process of fastening material, usually 2x4 and 2x6 dimension lumber, together to get the shapes and sizes you want. No way I can look at that photo and tell you if that's what you want to do for your shower not having any idea what you might be starting with. And I think it's a very bad idea for you to be posting photos like that on accounta people are gonna wanna base their answers on that being your framing.

If you could be a bit more specific with your question it might help. "Is it how you guys do it" isn't gonna buy you much. If I were framing that particular shower for that particular application, I might do it much that way. But it has parts that are not applicable to a Kerdi shower and may be lacking parts that might be important in your application.

If you're looking for a tutorial on wood framing in general, I'm afraid that might be a bit beyond the scope of our forums. If you have specific framing related questions, though, ask away and someone will likely be able to field most of them.

My opinion; worth price charged.