Hello All,
I recently bought a circa 1955 pier and beam house, and found out the kitchen subfloor under sink was absent. I looked into more of the subfloor and decided to pull it all up this past weekend. I’m gaining bits and pieces of knowledge online. I’m looking at putting down 1 1/8 inch tongue and groove plywood with cement board on top of that for porcelain tile. Does anyone have experience with subflooring install with tile? Any tips are appreciated.
Be sure your cement board seams are running bond and never line up with the tongue and groove, and you should be good. Ideally, make sure your joists are well enough marked on the walls that you can pull a chalk line and screw the cement board all the way down into the joists.
I’m a fan of two layers of 1/2 play, all seams staggered, screwed down, plus cement board, if your adjacent floor heights will support it.
Is that black mold? If so, address that while everything is open.
Yes it might be. I’ve been wearing a mask and need to tear out that sheet rock and plan to resheetrock both areas
Would you use regular plywood or tongue and groove for both 1/2 inch ply layers?
You probably won’t find half inch T&G, or even lap joint. I’d suggest one, or both layers 5/8 or 3/4 if possible, but most houses usually don’t have the ability to take that much thickness with the cement board, and keep the floor in alignment with adjacent floors.
And obviously, use some sort of adhesive between the wood layers. I suspect some sort of modern specialty product may exist for bedding the cement board to the plywood. I think the old style was a latex modified mud.
Before you get to the Tongue and Groove sub floor…
What are the piers made of ?
What is the condition of the piers? stable, sturdy,level etc?
What is the condition of your floor joists ? solid? none cracked, no insect damage, no water damage, no rot, etc?
What is the condition of the beams under the joists? (see joists above).
Note- this is not an all inclusive list of what to check or look for - but a start. Welcome to the world of owning an older home!
The key to having tile over wood is to have as little deflection in the floor as possible - a sturdy sub-floor is great - but if your joists are not up for the weight, it won’t matter.
Now is the time to make SURE you are building on a solid foundation (no pun intended)! I envy you - I’d prefer a pier & beam foundation over a shake and bake slab home any day.
Take a look at this system:
It’s a moisture resistant OSB subfloor that is T&G. Only need one layer.
You’ll also want to use construction adhesive on all the joists to help prevent creaking over time. Use screws specifically made for decking. Don’t use drywall screws.
Instead of hardiboard layer, take a look at Schluter Ditra underlayemnt membrane system. I use it all the time. This creates an uncoupling membrane that allows for some movement without grout or tile cracking. Being a wood floor joist system with a wood subfloor, there will be more seasonal movement than a concrete slab. This will help prevent cracking. (Matter of fact, I use Ditra on all flooring that will be tiled)
Also, with the floor open, you can add 1x2 or 2x2 cleats down on each side of the floor joists at an appropriate depth to allow you to add at least an R7 rigid insulation. I would get the exterior type with the radiant barrier placed towards the crawl space. This simplifies insulation prior to adding subfloor and make it much easier than crawling underneath.
Good Luck.
Tom makes a good. While it’s open and easy, how much extra cost to add a third support next to the existing ones? The photo already shows some that don’t go all the way across. You’ve done the hard work, ripping out the stuff so it’s exposed. Easy to do now and can prevent tile cracks later.
Haven’t done a kitchen but have done a bath. Have fun.
where does the dryer vent hose connect to & exit that is under the joists in a trench?
Interesting way to route whatever it is …
Owen you beat me to the crack isolation membrane by Schluter (dammit)!
Tom great minds think alike! You Da’Man!
There are other uncoupling membrane systems out there besides Schluter, but I really like the Ditra product. Simple to adhere with Unmodified thinset(less expensive) and just freakin’ works.
Trent -
I cannot emphasize this enough - if you discover any galvanized water supply piping during your remodel - now is the time to remove it and go with copper or pex.
Galvanized pipes may still “appear” fine visually but they are very deceptive since they rot from the inside out.
My $1.00 is on a downdraft cooktop vent.
You guys seem to really like Schluter, but I am not a fan. I’ve never used it because their marketing makes no sense to me. Do you use it strictly for “uncoupling membrane” or do you use it for “waterproof membrane” also (which is how I’ve seen it advertised the most)?
on the galvanized pipe replacement!
and clay sewer pipes.
I think those are cast iron waste pipes - something I’d have a camera down if it were my house due to the age. joints on those pipes with lead and oakum and were susceptible to root penetration, that and iron pipes tend to rust out on the bottom from decades of use…again, better now then after a new floor, new walls, appliances etc are installed.
As you are noticing, this is a great opportunity to really upgrade that 1955 home. As Tom mentioned, get rid of any galvanized water pipes. Copper is great if you know how to sweat, but PEX is the way to go. One thing to realize though, is rats will chew on it. You can create a manifold system very easily to route to all areas of your new home. Also, take a look at your wiring and waste lines. If you have cast iron waste lines, inspect closely and replace with SCH40 PVC. Of course, budget allowing to upgrade if possible.
It’s called remodeling creep. It will take longer than you expected and cost more than you thought. But by adding your own sweat equity, your home will be worth more than the dollars spent. Plus any satisfaction you may get by DIYourself.
Curious: Has anyone ever run PEX inside flexible armored electrical conduit to defeat rats? At least in areas of high exposure? Is there an aromored PEX?
Andrew, I use Schluter for everything. Uncoupling and waterproofing. It works great, much better than mud bed in my opinion. I have never demoed a mud bed system that had not failed. I’ve demoed one Schluter shower system and it had not failed.
I’m a believer. What doesn’t make sense to you?
That’s a good question. I’ve never seen it done, but not a bad idea. Maybe run it though PVC electrical conduit that is 3/4”?
There is NO WAY it’s waterproof, but they sell it like it is.
And I know contractors by the buckets love the stuff, and SWEAR it’s waterproof, but I just don’t believe them.
As an uncoupler, I’m sure it’s as good as anything else and maybe better…
