Any advice on a percentage to add as waste.

The suppliers say 10% as they always do. That suits them.

I rather favour 5% but the risk is of being short and not getting matching spares.

It must depend greatly on the skill and mindset of the tiler too.

Am I right in thinking that big tiles have more waste?

 

Add more the bigger your tiles are. 
a room 1810 wide being tiled with 1200 long tiles will eat tiles and cause lots of waste as the off cut can’t be used in the next row. 

I usually go for 10% as you are going to really annoy the tiler for a small saving. If they charged you a couple of extra hours to come back it would more than offset any saving.

 

BUT

 

I always measure it myself and allow for baths, doors etc. I have seen bathroom fitters just measure the room and ask me to order tiles to cover er the whole room, even though a door takes up almost 2 square metres. So I would tend to measure the actual area being tiled and add 10%.

 

I also try and make allowances for the size of the tiles and likelihood of cuts being required. If I think it is a flat area and a small number of cuts will be required I might go nearer to 7-8%, if it is complicated and needs lots of cuts I might go 10% or even a bit more.

 

Another thing to consider is how easy will it be to get an extra box. If you can nip down to Topps for another box fair enough, if you have to wait two weeks for them that is another matter.

10% as above, I think it’s better to have a couple of boxes stashed for future as they end up obsolete so fast, in case of damage etc.

 

I seem to have usually 5% left over.

If I've done it myself there will be actual waste due to mistakes, but the thinking out will have allowed offcuts to be used.

If it's a professional then I don't expect many errors, and a polite discussion should avoid lots of big bits left over.

 

Big tiles in small rooms won't be happening. Also I have prevailed in there not being bold patterns.... I hate seeing repeats in something pretending to be natural.

 

 

 

1 minute ago, Eric said:

in case of damage etc.

In real life though, are they still in store in case of damage? I can't recall ever having to use one. It would be relevant if changing fittings I suppose.

 

3 minutes ago, Eric said:

10% as above,

We strive to get another 5% off the supply  price then happily put 10% of the cost in the garden shed for ever.

 

Would any suppliers set a box aside just in case? Of course they don't want to, but just might fof a very short period.

46 minutes ago, saveasteading said:

In real life though, are they still in store in case of damage? I can't recall ever having to use one. It would be relevant if changing fittings I suppose.

 

We strive to get another 5% off the supply  price then happily put 10% of the cost in the garden shed for ever.

 

Would any suppliers set a box aside just in case? Of course they don't want to, but just might fof a very short period.

They are still in the attic of the house when I sold it 😉

Worth asking if they would keep some for you. I have tiled 2 houses and could never get the same ones that’s why I don’t mind having spares just in case.

 

I've got to tile a utility and kitchen floor - actual m2 is 14.5 - I'll order 16.5 - In the past I've found 10% just too tight - running before the job is finished and then having to get more is a PITA

2 hours ago, saveasteading said:

In real life though, are they still in store in case of damage? I can't recall ever having to use one. It would be relevant if changing fittings I suppose.

 

In real life, copper pipes under the floor might spring a leak (pinholes in bad copper that had been down for 20+ years and eventually corroded through) and you might need to dig stuff up to find the leak and effect a repair... 

 

 

I may tile the garage toilet/utility in a mix of old tiles for fun and mean-ness, I mean economy.