In a word – yes, but it shouldn't be assumed that what arrives will definitely be from the same batch. There are a couple of issues here that an installer, whether it's a customer doing a DIY installation or a professional installer, must consider BEFORE they start tiling.
But first, here's how we work. When goods arrive at our warehouse, each crate is allocated a unique batch number. Our warehouse staff have specific instructions to only pick orders from one batch number. That way, we can reasonably guarantee that what arrives with the customer will all be similar in nature. It's not too much of an issue with natural stone if batches are inadvertently mixed as long as the tiles are all from the same stone in the same quarry. As natural stone products like marble tiles or limestone tiles are unique in every way, there isn't too much of an issue if batches are mixed, but our staff have instructions not to.
Porcelain tile batches
Porcelain tiles present a completely different situation and we never knowingly dispatch a porcelain tile order from different batches. Unlike say travertine tiles, porcelain tiles are man-made using sophisticated machinery and blends of natural products to create the finished article. One batch of raw material used to produce one batch of tiles may differ slightly to the next batch produced. Sometimes, even different machinery can be used to produce the same tiles in a completely different factory, and while the overall appearance of the tiles will be the same, they might not match up exactly to each other when put side by side.
While natural stone tiles are generally packed individually into crates, porcelain tiles come in boxes. On the side of every box are a set of numbers that identify which batch each box came from. When we dispatch orders, our warehouse staff will check two things:
The order will only be picked from tiles relating to one of our internal batch numbers.
The batch numbers on the side of the boxes are checked to ensure they all match each other.
With the best will in the world and taking into account that our warehouse staff are only human, there is always the possibility that boxes from different batches are mixed up and dispatched together.
It is standard practice for an installer to check that what they have received is correct BEFORE they start an installation. One of these checks is to ensure all the batch numbers on the side of the boxes are identical. There are specific guidelines for this in the code of practice BS.8000 PT.11 “workmanship on building sites” (a copy of relevant parts is available upon request).
In the unlikely event that tiles are supplied from two different batches in one consignment, it simply isn't acceptable for an installer to just throw up what they have been supplied only to find out that the shade and colour starts to change once they are ¾ the way through a glorious bathroom tile installation. “I just fitted what I was supplied missus” is no mitigation.
These situations have arisen before and typically when a sales person gets the call, and we determine what batch is required to finish the job off, it's always the one we don't have left in stock – that is sod's law! The fact of the matter is that we should get the call in advance of the installation to say there are two different batches here, what are you going to do about it? That way we can make arrangements to swap the goods over and remedy the situation. Unfortunately, whatever the circumstances, there is no going back once the tiles are on the walls even if we have inadvertently supplied them incorrectly.
Ultimate responsibility for checking they are correct and all from the same batch lies with the installer before they start the installation.
Even if all the tiles are from the same batch and say you have under-ordered, there is always the possibility that the ones you will receive to complete the job might be from a different batch which could cause you major issues if they don't match exactly. It's always better to order more tiles than you need for this reason (typically 10% over and above the room area) and it also allows you to have a few spare for the odd unforeseen emergency down the line, or if your plumber hasn't tightened up your shower valve properly and somebody has the unfortunate job of smashing off a few tiles to rectify the situation! It does happen….