Thread: ceramic tile lippage inspection procedure

Our company has been tasked with doing a tile lippage inspection on 4x4 ceramic wall tiles. I am a third party inspector am not usually involved in inspection of finishes. The tile work is in an area of the new McCarran Airport Terminal 3 complex. The walls have wash lighting and the lippage problem is severe.

My problem is finding a procedure to do this inspection. I have found numerous references to the 1/32" allowable lippage. What I need to find out is how to do this over large areas, where the owner wants to have every tile measured. There a 6 walls, approx. 100' long x 8' high, with numerous alcoves for entry into the people mover.

I need to have a procedure that will stand the scrutiny of the tile contractor, the general contractor, and be defendable.

HELP........................................

Thanks, Dennis

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Originally Posted by Dennis Niebuhr

My problem is finding a procedure to do this inspection.

You'll have to invent one that works for this job site. A jig could be made to find tile that exceed the 1/32 inch allowable lippage. Then you can mark each one. Sounds very tedious.

I have found numerous references to the 1/32" allowable lippage.

The TCA posts that ANSI here:

TCNA - Technical Services: FAQ

the owner wants to have every tile measured.

He (owner) should have specified the desired outcome in the contract. I bet the GC didn't spell it out at all when he hired the tile sub.

I need to have a procedure that will stand the scrutiny of the tile contractor, the general contractor, and be defendable.

That's a great point, but I think you should consider what happens when the 3 parties can't agree after 60 days of wrangling, and they want you to justify your protocol to a large group of suits in a wood paneled conference room.

Some things just aren't worth the trouble, but maybe you can pull it off. Good luck & charge accordingly...

Dom.

Originally Posted by Dennis Niebuhr

The walls have wash lighting and the lippage problem is severe.

"The walls have wash lighting and the lippage problem is severe."

I suspect you mean (underlining and bold are mine) "The walls have wash lighting and the lippage problem looks severe."

Until you have measured the lippage and the warpage you should NOT be saying that it "is" severe. That taints your apparent supposedly unbiased position of determining *IF* it "is" even a problem. Hopefully you select your words more carefully elsewhere than here.

You would first need to measure the warpage of the tiles, then the apparent lippage. You will be measuring the combined lippage AND warpage, so you would need to know the warpage to know how much to deduct from the measured 'apparent' lippage to end up with an actual lippage measurement.

Keep in mind that you will want to measure over a large area (compared to the 4x4 tiles) to ascertain a plane at which the tiles should be in. You could do this with a long straight edge (6 foot to 10 foot in length, probably an 8 foot long straight edge would by ideal as that would allow you to measure floor to ceiling as well as measure horizontally and diagonally, keep in mind that if there are any places slightly less that 8 feet high floor to ceiling that your straight edge will not fit, so maybe 7 feet 11-1/2 inches to allow for a 1/2 inch variation in height) and that 'straight edge' is indeed "straight" - you are trying to determine if the tiles are only 1/32" to 1/16" or less "in plane", which would include lippage and warpage, and if any given tile had no warpage but was installed out-of-pane with the wall and other tiles, then the lippage would be exaggerated on the high side and the low side of that tile in relation to the adjacent tiles.

You could come up with a good measuring system, present the measuring system to all parties, have them sign off on the use of THAT measuring system, and the results would be based of THAT measuring system.

The results would then fall where they will and you SHOULD NOT CARE what the results are as all you are doing is documenting THE WAY IT IS.

You will likely want to use feeler gages or a depth reading dial micrometer to measure with as the 1/32" is not going to be easy to read by other conventional means.

Originally Posted by Dennis Niebuhr

Our company has been tasked with doing a tile lippage inspection on 4x4 ceramic wall tiles. I am a third party inspector am not usually involved in inspection of finishes. The tile work is in an area of the new McCarran Airport Terminal 3 complex. The walls have wash lighting and the lippage problem is severe.

My problem is finding a procedure to do this inspection. I have found numerous references to the 1/32" allowable lippage. What I need to find out is how to do this over large areas, where the owner wants to have every tile measured. There a 6 walls, approx. 100' long x 8' high, with numerous alcoves for entry into the people mover.

I need to have a procedure that will stand the scrutiny of the tile contractor, the general contractor, and be defendable.

HELP........................................

Thanks, Dennis

I don't think I would start out trying to measure the entire wall. As a start I would ask the owner to identify a 10' section that is of concern to them, ask the tile guy to identify a 10' section they think is perfect, and the GC to identify a 10' section they think is in question. Do your test on those sections and then expand from there. These three areas should help the three sides see a real problem or no problem.

Originally Posted by Dennis Niebuhr

the owner wants to have every tile measured.

I never thought about an airport having an owner...

seems to me it would be pretty accurate to do random sampling, an x-y axis and random number generator, but if they want them all checked, that's what they want.
Sounds like a job for Forrest Gump or Rainman to me.

Thinking about this more, I wonder if you could take digital photos and measure the shadows. Once you got a correlation baseline, it might be pretty accurate. a good computer programmer could probably write a program to measure and report each shadow.
all in all, probably cheaper to change the lighting.

Originally Posted by Jerry Peck

You would first need to measure the warpage of the tiles, then the apparent lippage. You will be measuring the combined lippage AND warpage, so you would need to know the warpage to know how much to deduct from the measured 'apparent' lippage to end up with an actual lippage measurement.

Keep in mind that you will want to measure over a large area (compared to the 4x4 tiles) to ascertain a plane at which the tiles should be in. You could do this with a long straight edge (6 foot to 10 foot in length, probably an 8 foot long straight edge would by ideal as that would allow you to measure floor to ceiling as well as measure horizontally and diagonally, keep in mind that if there are any places slightly less that 8 feet high floor to ceiling that your straight edge will not fit, so maybe 7 feet 11-1/2 inches to allow for a 1/2 inch variation in height) and that 'straight edge' is indeed "straight" - you are trying to determine if the tiles are only 1/32" to 1/16" or less "in plane", which would include lippage and warpage, and if any given tile had no warpage but was installed out-of-pane with the wall and other tiles, then the lippage would be exaggerated on the high side and the low side of that tile in relation to the adjacent tiles.

You could come up with a good measuring system, present the measuring system to all parties, have them sign off on the use of THAT measuring system, and the results would be based of THAT measuring system.

as I understand lippage, it is the height or difference compared to the adjacent tiles and not to the flat plane of the wall or floor and warpage of the tile doesn't make lippage "OK". doesn't really matter if the problem is the tile or the installer. am I wrong on my interpretation?

Since your company has already been hired, I would imagine that a fee has been set, and has to be taken into consideration (unless the fee is by the hour and the amount or hours allotted is open ended). Bear in mind you have horizontal, vertical, and diagonal planes.

I think the person (or entity) that is complaining (which is probably the property owner) should select an area to survey, and I believe that a 10' x 8' section should give a reasonable representation of the installation, although whatever your company approves, and your company's client is willing to pay for is what should get done.

Unless you have some extremely sophisticated equipment (if such even exists), I think Jerry's technique (straight edge and feeler gauges) makes the most sense, is the most accurate, can be recorded, will be understood and will not be disputed.

Your findings could be represented using a graph; each box represents a tile, with measurements in each corner (and possible center) of each tile. You would need separate graphs for each plane inspected. Make sure your straight edges are true.

You may end up with graphs that are a "sea" of numbers, so in addition you could provide a color coded graph (red dots representing locations more than 1/32" faults), so the findings could be visually interpeted.

I would also suggest that you submit your method of testing and area(s) to be tested before you begin. However you do this; you only want to do it once.

Originally Posted by Benjamin Thompson

I never thought about an airport having an owner...

seems to me it would be pretty accurate to do random sampling, an x-y axis and random number generator, but if they want them all checked, that's what they want.
Sounds like a job for Forrest Gump or Rainman to me.

Thinking about this more, I wonder if you could take digital photos and measure the shadows. Once you got a correlation baseline, it might be pretty accurate. a good computer programmer could probably write a program to measure and report each shadow.
all in all, probably cheaper to change the lighting.

.

It would be almost impossible to measure offset depth by measuring shadows created by typical lighting conditions using a digital camera due to the size of the apurture and a condition known as penumbra.

Originally Posted by Benjamin Thompson

as I understand lippage, it is the height or difference compared to the adjacent tiles and not to the flat plane of the wall or floor ...

Sort of correct.

Technically, lippage is the difference between adjacent tiles and the projection of one edge beyond an adjacent edge.

However, if you were to use a straight edge across the tiles (which would be the plane of the wall) you then have a straight reference line from which to measure the tile at any given point on any given tile along that reference line.

From those measurements you can determine both lippage and warpage.

Did I explain it more clearly this time?

... and warpage of the tile doesn't make lippage "OK".

Sort of incorrect.

Let's say that the allowable lippage is 1/32" and you measure the 'lippage' at 3/64", you may want to call that out as excessive lippage, except that you do not know if you measured "lippage" only or not.

You now need to measure the "warpage" of that tile, and if the "warpage" of that tile to the edge where you measured your 'lippage' measurement is 1/64", then the actually "lippage" is your 'lippage' measure of 3/64" minus the "warpage" measurement of 1/64", leaving a "lippage" of 1/32" (2/64") which is within the allowable 1/32" "lippage" stated in that standard.

As such, then, "warpage" CAN turn excessive 'lippage' into OK "lippage".

That is explained in the link Dom provided, but maybe it was not explained well in that link.

.

Keep in mind that washing the wall with light from above, below, or one side, will show EVERYTHING which is not perfectly flat, and the lippage allowance means it is not perfectly flat ... just close enough to being flat to deem the work acceptable by contract.

The contractor should have laid up a field sample, had the architect and owner accept the sample, then the actual work would be judged in relation to the approved and accepted field sample. The problem which rears its ugly head here is that the contractor don't think about the consequences and have their BEST workers lay up the field sample, then have any worker do the work! What the contractor should have done is have their WORST workers lay up the field sample, once approved and accepted, that sample represents the acceptable level of work, and any of the other workers can DO BETTER than the field sample.

doesn't really matter if the problem is the tile or the installer. am I wrong on my interpretation?[/quote]

I wonder if you could rig a laser light at the correct ht on a handle so that if the light is stopped by a tile edge, you mark the high spot. I'm thinking it could speed the process up a bit, because you could blast right over areas where the tiles are within the tolerances.

I can feel the contractor's pain a bit, if the problem relates to tile warpage. We bought some long narrow tile last year for our kitchen wall, special order from Mexico. No, it wasn't my idea, but it's not my kitchen, eh? About a third of the way around, we noticed the tiles were bumped up in the middle. Quite a few of the tiles were warped enough to cast shadows under certain lighting. I went through all the boxes and picked the straightest ones for the larger surfaces and used the warped ones where we had to cut. The end result is pretty nice, but there was a box and a half of extras left over, all warped.

Originally Posted by Dennis Niebuhr

Our company has been tasked with doing a tile lippage inspection on 4x4 ceramic wall tiles. I am a third party inspector am not usually involved in inspection of finishes. The tile work is in an area of the new McCarran Airport Terminal 3 complex. The walls have wash lighting and the lippage problem is severe.

My problem is finding a procedure to do this inspection. I have found numerous references to the 1/32" allowable lippage. What I need to find out is how to do this over large areas, where the owner wants to have every tile measured. There a 6 walls, approx. 100' long x 8' high, with numerous alcoves for entry into the people mover.

I need to have a procedure that will stand the scrutiny of the tile contractor, the general contractor, and be defendable.

HELP........................................

Thanks, Dennis

The last word in you post "defendable" might be a problem (it is actually "defensible") if you have no experience in tile inspections. You might want to reach out to the Tile Council of North America (TCNA). They produce industry standards and guidelines for tile installations. They have just about every specification for almost any type of install.

Also, I would want to see the original specifications for the tile install.

I would not take this job. Leave it for someone who claims to have expertise in the tile installation issues. In this scenario, no matter what you say, you are going to hack off someone with deep pockets and you will have almost no experience, standards etc to use for defense. JMHO.

When I worked for a company that sub-contracted to NASA we had to create a procedure to inspect a component that had never been built before. We had NASA, the general contractor, and all the subs that worked on the project sign off on the new procedure. This was specifically so the procedure could be defensible in a court of law. We did this on several ocasions with no retrobution since all the parties involved agreed in advance as to the testing standards by which we would be qualifying the component. I would certainly use any specifications for installation and variences for that particular tile that can be provided by the tile counsel while creating any type of inspection procedure. Sometimes the most effective testing method isn't always the easiest or most time efficient.