I'm laying 2" x 2" tiles over a raised concrete patio slab that is 11' 6" by 16' 1 1/4". The tiles come in 12" x 24" sheets with the individual tiles joined by little blobs of a rubbery substance. Across the width of slab I think it will work out nicely. But going the other way I've got to either make the slab 3/4" longer or gain 1 1/4" over the 16' 1 1/4" dimension. If I put the extra space between the sheets of tiles that works out to adding about 1/16" (1.2 mm) between each sheet. Since the tiles are spaced 1/8" (3 mm) apart in the sheets this seems like it would result in a noticeable difference.
So, I'm wondering how large a difference would be noticeable? For example if I cut the sheets apart in the middle, I could increase every third by a bit more than a 32nd of an inch. Would that stand out?
Best Answer
To put this in perspective, with my current browser settings, 1/32" is only slightly wider than a capital 'I'. It's narrower than a piece of aggregate in sanded grout.
Consider the following (scaled as 1 pixel = 1/32"):
Can you tell at a glance which gap is a pixel wider? Keep in mind that it's even less perceptable with lower contrast. How about this one?
Do a dry layout and have somebody else (preferably somebody who doesn't know about the spacing) look at it. I'm guessing it isn't going to be noticable at all. Truth be told, even a fantastic tiling job isn't going to maintain spacing tolerances of 1/32" on any consistent basis.