Overlap during installation should not exceed 33%, 50% overlap not recommended

[Packard]

I am looking at some 12" x 24" slate-look ceramic tile for a bathroom.  It does not say if it is porcelain or ceramic. The tiles have rectified edges, a look I prefer. 

It does say this about overlap and I have no idea what it means.  I've tiled just one bathroom in the past and it turned out fine.  But I am far from an expert at this.

Overlap during installation should not exceed 33%, 50% overlap not recommended

https://www.homedepot.com/p/Traffic...case-CR081224HD1PV/303517940#product-overview

Can someone tell me that that means?  The other tile I installed was 12" x 12".  Will this create any special difficulties?  I did buy one piece and check to see if my tile cutter could cut it and it worked just fine in the 24" direction.  I don't see an issue in cutting it in the 12" direction.

 

[Dr. P. Venkman]

If the tile is slightly domed, putting the (lower) end of one piece right next to the (higher) center of another piece will make that more visible.  Putting the end next to the (not quite as high) 1/3rd point will hide it a little better.

Here are a couple of writeups on lippage and overlap/offset:
https://www.tileoutlets.com/blog/managing-lippage-why-offsets-matter-when-installing-tile/
https://www.tileletter.com/why-do-manufacturers-require-a-33-offset-brick-pattern/

 

[dallas8338]

Overlap is the spacing between the next row of tiles.  25% is recommended for this tile- so you won't see any common seams but every 4 rows.  If you do 33%, then every 3 rows would share seams, and if you did 50 (not recommended) you'd see common seams every other row. 

The reason is this tile would likely crack if you laid it at anything closer than 33% as the differentiated spans would help distribute/span the load over more tiles.

 

[Packard]

I was going to use a straight set and not a brick lay.  Would it look weird using straight set on a 12" x 24" tile?  The pictured pattern was my plan, and the tile looks essentially similar-- a slate look porcelain tile.  Though the pictured tile looks more like 12" x 18".

 

[dallas8338]

I was going to use a straight set and not a brick lay.  Would it look weird using straight set on a 12" x 24" tile?  The pictured pattern was my plan, and the tile looks essentially similar-- a slate look porcelain tile.  Though the pictured tile looks more like 12" x 18".

This is essentially 100% overlay and not recommended for the tile you linked.  The reason, though I can't seem to find the info on HD website, is that the tile will crack, especially at the grout lines, unless you have a super solid substrate like concrete.  Given the price I bet it's a ceramic tile.

 

[Packard]

Thanks for that. I will try to find some 12" x 12".  I've set that before with no problem. 

 

[Peter_C]

I was going to use a straight set and not a brick lay.  Would it look weird using straight set on a 12" x 24" tile?

I set entry way tile for someone that way. It looked okay, but that is a personal decision.

Personally I would never use ceramic tile on a floor. One hard item drops onto the floor and it chips. Same goes for cheap Porcelain. On the cheap stuff the edges tend to chip easily. Rectified makes tile setting easier.

If you are not familiar with Schluter Systems I would recommend reading up on it. From showers to floors there are major advantages.

 

[Packard]

It is on a slab. I don't think I need the schluter system layer.

 

[tjbnwi]

I am looking at some 12" x 24" slate-look ceramic tile for a bathroom.  It does not say if it is porcelain or ceramic. The tiles have rectified edges, a look I prefer. 

It does say this about overlap and I have no idea what it means.  I've tiled just one bathroom in the past and it turned out fine.  But I am far from an expert at this.

Overlap during installation should not exceed 33%, 50% overlap not recommended

https://www.homedepot.com/p/Traffic...case-CR081224HD1PV/303517940#product-overview

Can someone tell me that that means?  The other tile I installed was 12" x 12".  Will this create any special difficulties?  I did buy one piece and check to see if my tile cutter could cut it and it worked just fine in the 24" direction.  I don't see an issue in cutting it in the 12" direction.

What they’re referring to is the layout bond. When you look at most brick walls you’ll notice that the one brick covers the other 50%, this is called half bond or running bond. If the pattern goes straight up-stack bond. 

On tile no more than 1/3rd bond is the spec set in the TCNA. This means that the tiles long edge will be no more than 1/3rd past the short edge of the preceding course.

As mentioned above the reason is the crown in the tile. If you go to half bond there is more of a chance that the tiles will lip as mentioned above.

You can alleviate some of the lippage by using lippage clips. Below are pics of the clip system I use. The wall is marble, the floor is porcelain.

Porcelain tile is ceramic tile that has a different clay composition and is fired to be harder.

A stack bond for your tile will be just fine.

What is the sub-floor your setting over?

Tom

 

[Peter_C]

It is on a slab. I don't think I need the schluter system layer.

Maybe. Slabs do crack, and that is exactly when Schluter Systems comes into play. NobelSeal is another option.

Is the height of the floor next to it the same as the tile? My personal preference is for no transition pieces and dead flat between flooring types. There are times the tile needs to stay as low as possible though.

 

[Packard]

A few of reasons I feel confident on this slab.

The house was built in 1953.  For 68 years the slab has not cracked and the existing tile was solid and in good shape.

The floor I installed a number of years back has shown no cracks.

It seems unlikely that it would decide to crack after all these years.

My house is the builder's own home.  He built about 40 homes in the immediate area.  All the homes featured 2" x 8" floor joists.  But this house has 3" x 8" joists.

The concrete is "hardened".  I have no idea how that is done, but I was told that was the case.  None of the Ramset .22 power loads will penetrate the concrete (even the most powerful ones) and the carbide-tipped drill bits only last about 4 holes.

All of which is to say the builder built his personal home using premium specs.  Where all my neighbor's homes are done in sheetrock, my home has metal lathe and plaster (a nuisance for WiFi reception).

So I have faith in the concrete.  The previous owner added a 3 season room over a deck and there are cracked tiles on that floor. 

I thank everyone for the information. 

Packard

 

[tjbnwi]

Stack bond will be fine with your tile.

Make sure you back butter.

If you are going over the original tile use Mapie Eco Prime.

Tom

 

[Packard]

Tom,

Thanks for that information.

 

[Ron B]

A few of reasons I feel confident on this slab.

The concrete is "hardened". 

This is just a guess.  If your concrete is richer in cement, then it is harder.  i.e. a 6 bag mix is better concrete than a 5 bag mix.  Also, weather conditions.  Concrete does not really dry out, it is more of a chemical reaction.  The more time it has to set, the longer the chemical reaction molecule chains are.  So concrete poured on a hot day will not be great concrete, but concrete poured on cool fall day and kept moist will be much better concrete. I am not a concrete person, we just poured a lot of concrete on the farm in one of those little tractor PTO mixers back in the 1960's.  Dad always said bridge pier concrete was the hardest.  That is a different type of cement (concrete has different formulas, like Type N).  There, you now know everything I know about concrete.

 

[Packard]

Unlike most concrete that I've seen this concrete is extremely smooth as if the sand they used was almost a powder and not grains of sand.

It is also more nearly gray than sand-colored.  So I suspect they used something other than sandbox sand in the mix.

 

[Peter_C]

You didn't ask...but I'll try to help with more information.

The type of grout you use can play an important part in long term cleaning. The old skool grout of yester-years sucks. It absorbs black crap and can be next to impossible to clean even by acid washing, and sealing doesn't really do much. I switched to Laticrete epoxy a long time ago for 1/8" grout lines, which makes cleanup a breeze, especially for showers. Others swear by Mapei's single part grout. Those that hate epoxy, don't own a kitchen scale to break it down into smaller batches. Epoxy is more work either way, as installation cleanup is far more physical.

FWIW the john bridge forum is very accepting and helpful for all people performing tile work, whether a pro, or happy home owner trying to do their first tiling job.

When I ground my garage floor, I sprayed a densifier down before spraying a sealer on. Supposed to help harden it *shrugs* the sealer sure does work though, as liquids do not penetrate the surface. No way would I ever put down an epoxy floor in a garage with a welder.

Unlike most concrete that I've seen this concrete is extremely smooth as if the sand they used was almost a powder and not grains of sand.

It is also more nearly gray than sand-colored.  So I suspect they used something other than sandbox sand in the mix.

Probably has more to do with troweling the concrete as it dried. They brought the slurry up and pushed the larger rocks etc. down. Grind it or cut it open and you will find larger rocks. If it isn't cracking at all, then the builder probably put lots of rebar, and better than average depth of concrete, which is good. Many houses here in NorCal are Eichler's which are slab on grade and pretty much all of them are cracking 60 years later. I just saw one that had cracks which had to be ground flush in order to install vinyl flooring throughout. Kinda scary as they used copper pipe for radiant heating. Water leaks are common, and require smashing the floor open to repair (Pex tubing wasn't invented yet.)

 

[Packard]

None of the poured concrete in the house has cracked anywhere.  I do see some mortar between the cinderblock walls in the basement with hairline cracks, but they were patched when I moved in 22 years ago and nothing has changed since then. 

Basically, all the issues I have had with the house relate to "improvements" that have been made over the years.

My biggest gripe is that the garage is built over a crawl space and that crawl space stays cool all year long.  So in the rainy weather in the summer the water condenses on the garage floor.  A good humid day will leave a continuous puddle of water on the floor.  There is never enough to drain off (there is a drain in the middle of the garage), but it is annoying.

 

[Packard]

My knees and back hurt, but the installation with 33% overlap went well.  (Oh, and my shoulder hurts too.)  I am really not fond of installing floors.