[123pugsy]

I was talking to a friend who's also a contractor and he recommended screen and scratch coat for my 48" x 8" porcelain tiles.

9-1/2" TJI's at 12" center, 12'-6" span with cross blocks at center.
3/4" Advantech sub floor.

If you use this method, what size staples do you use?
I have a good compressor to use, just want to be able to use good staples that aren't going to sticking up when I'm ready for the scratch coat.

How about staggering them?
What's a good way to do this to look good?

Fire away all other comments as well please. :wink2:

 

[JazMan]

You may have guessed no one here is gonna bless a "scratch-coat" "Jersey Mud" job as it is not considered an approved way to install floors. I know it's popular around your neck of the woods, and I also know it can work most of the time.

A question for you. Why? Why use a method that has never passed when tested by any testing association?

As for the floor, how flat is it when measured with a 10 ft. straight edge?

Jaz

 

[123pugsy]

Thanks Jaz.

I did not guess why there were no responses.
Scratch coat is very common around here, so I figured was acceptable.

However, since building the new house, I have noticed that every trade I've hired has not given a %$#^%$# as to doing things properly, just interested in getting paid.
Maybe that's why they use it still, as it won't crack for a couple or few years and they've gotten their money and moved on to other victims.

All that said, let's move on to the correct method.

Schluter or similar membrane?

I'll have to check with a straight edge later. I only have an 8'er though.

 

[JazMan]

An 8 footer will do, but I used to use several including some short ones too as needed.

Unfortunately some trades work on a guaranteed until the check clears mentality. Even some who believe they do good work don't cuz they don't know and they don't know they don't know. Others just keep doing things the way they've always done them.

Your joists/subfloor combo should be fine for most any ceramic tiles. Just need to make sure the floor is flat enough and then decide on the membrane or concrete backer. Then small details.

Jaz

 

[123pugsy]

Cement backer sounds a lot cheaper. Are you referring to cement board?

Thanks.

 

[JazMan]

Yes, CBU, (cementitious backer unit). It's cement while in the bag or as it's mixed, concrete when it's dried.

Most CBU's are about half the cost of Ditra, actually closer to 40%, here in the USA. There's a bigger difference in good ole CA. I hear Ditra can be $3 or so Canadian. No wonder the hacks........ah..ah..I mean some of the handymen go scratch coat.

Jaz

 

[123pugsy]

A friend of mine recently used cement board as a backer for his marble tiles and he says that he has a few fine cracks exactly at the cement board seams.

So optimum would be to use the Ditra. Would you consider the couple and change bucks a square foot cheap insurance?
Actually, it's a buck and change if I discount the cost of the cement backer.

 

[123pugsy]

How is this Ditra laid down?
Nails, screws, thinset?

 

[123pugsy]

Forgot to mention, the floor is very flat. This is a brand new house I'm building.
I just need to sand a wee bit where the sub floor has swelled at the end of one sheet.

 

[JazMan]

Swelling of the OSB is a concern. Some how it was installed too tight, however I thought that wouldn't happen cuz Advantech has built-in spacer design. Might wanna call them.

Thanks for the info that your subfloor is very flat. However, I don't know your definition of very flat, and new house makes no difference.

Ditra is thinset to the floor using an appropriate type for the substrate. Tiles are installed over Ditra using a premium unmodified thinset.

Did your friend reinforce the joists and install a second layer of plywood before the CBU? I bet he did not. Natural stone tiles require a much stiffer base than ceramic. It's also possible that he did not tape the seams too.

The darn stuff costs more there, that's what happens when your government gives you "free" stuff.

Meet me at the Windsor/Detroit border for a great deal on Ditra. :wink2::biggrin2:

Jaz

 

[123pugsy]

Swelling of the OSB is a concern. Some how it was installed too tight, however I thought that wouldn't happen cuz Advantech has built-in spacer design. Might wanna call them.

Thanks for the info that your subfloor is very flat. However, I don't know your definition of very flat, and new house makes no difference.

Ditra is thinset to the floor using an appropriate type for the substrate. Tiles are installed over Ditra using a premium unmodified thinset.

Did your friend reinforce the joists and install a second layer of plywood before the CBU? I bet he did not. Natural stone tiles require a much stiffer base than ceramic. It's also possible that he did not tape the seams too.

The darn stuff costs more there, that's what happens when your government gives you "free" stuff.

Meet me at the Windsor/Detroit border for a great deal on Ditra. :wink2::biggrin2:

Jaz

Ends of Advantech are square cut, only long sides have built in spacers.

Do you figure if it's too tight, it would cause it to swell? The framers installing them butt them together after I told them they need a 1/8" space. Typical "this is how we always do it" answer. Should I call them to saw cut every joint in the whole house now?

Very flat is 1/16" gap over 8'. That's what I seen in a couple spots.

As for my friend, not sure if he added plywood or taped the seams. Perhaps they did neither. He had a tile dude do it for him. And as you know, a lot of "Jersey mud packers" around here.

I think I'll go with the Ditra. I like the idea of using the tape at the seams and walls, but jeez, is it expensive. 30 bucks for 16' of tape. Kereck corners are 18 bucks for 2 lousy pieces..... :surprise:
The Ditra is 320 bucks for 150 sq feet

The border is about 4 hours from my location. Any savings would be out the tailpipe. I wish I were closer.

 

[JazMan]

Should I call them to saw cut every joint in the whole house now?

Yes, it's gonna pucker again when humidity is high.

If it's only 1/16" in 8 ft. when measured from two high points, that's good enough. The spec when installing large tiles is within ⅛" in 10 ft. AND 1/16" in 24". Do you still pass?

I think your friend got a lousy installation.

Sorry about the cost of Ditra in Canada. Sounds like you're gonna try to waterproof the room with Kerdiban on the Ditra seam and flash up the walls? How are you gonna treat the doorway? You don't need to buy those corners, you can easily make your own as we did before they started to make them. I'll have to see if I can find an old video someplace.

Yes I know it's over 4 hours to drive, but of course I was kiddin. However.......if you're ever in the Buffalo area......... 54 sq. ft. rolls are $86 USD. Hey it's only money.

Jaz

 

[123pugsy]

Yes, it's gonna pucker again when humidity is high.

If it's only 1/16" in 8 ft. when measured from two high points, that's good enough. The spec when installing large tiles is within ⅛" in 10 ft. AND 1/16" in 24". Do you still pass?

I think your friend got a lousy installation.

Sorry about the cost of Ditra in Canada. Sounds like you're gonna try to waterproof the room with Kerdiban on the Ditra seam and flash up the walls? How are you gonna treat the doorway? You don't need to buy those corners, you can easily make your own as we did before they started to make them. I'll have to see if I can find an old video someplace.

Yes I know it's over 4 hours to drive, but of course I was kiddin. However.......if you're ever in the Buffalo area......... 54 sq. ft. rolls are $86 USD. Hey it's only money.

Jaz

Thanks. I'll probably grab the ol Skilsaw and run gaps myself. I'm sure the framer will run right over when I mention it to him....not..:vs_mad:
I'll check the 1/16" in 24". I can better check after getting all the blobs of drywall mud off the floor.

My buddy's floor also had heater wires in the mix which surely can't help the cause.

I was thinking to fold my own corners. I had a feeling that's what the pros would do.
Waterproofing now with the tape around the edges is cheap insurance rather than having water seep thru my brand new ceilings below.

With the 30% exchange rate on our buck, the price is about the same.
So, we're not getting screwed too badly here. :wink2:

 

[123pugsy]

I'll have the floor prepped soon.

Should I run the Ditra in any particular direction? Seams perpendicular to the 48" direction for instance?

 

[JazMan]

It makes no difference how you orient the seams with Ditra. You can even use small pieces that some would consider scrap. Just use the right thinset and apply with the correct trowel and smooth out to get the air out.

Jaz

 

[123pugsy]

It makes no difference how you orient the seams with Ditra. You can even use small pieces that some would consider scrap. Just use the right thinset and apply with the correct trowel and smooth out to get the air out.

Jaz

Thanks.

I'll have a lot of little pieces as one wall is on a 45 and going thru a closet and then into a washroom.

This stuff is too expensive for there to be "scrap"