Indoor/Outdoor Tile Layout HELP! - Tile Advice

[Corinne]

Hi there

I’m new to Tile Forum and joined to get professional opinions because I really need advice. We laid 100m2 900 x 900 tiles internally in a perfect square formation transitioning three rooms with a 2mm grout line. The idea was to seamlessly transition this to the raised patio outside 55m2. We/our builders went to huge lengths to ensure the concrete for raised patio was the perfect size/dimensions to allow this to happen which includes 2 steps down to the garden level. Our patio doors are flush with the floor with very narrow sightlines so the patio area is very visible. However, now we’ve come to lay the Outdoor (20mm thickness) matching Tiles we’ve found they are 5mm less in size. I’ve discussed this with our tiler who has proposed three options

• Lay the outside tiles with a 7mm grout line (same brand/colour) to stay in matching square formation
• Lay the outdoor tiles with a 2mm grout line, following the grout line of the middle tile and accept all the others will be out by 5mm, 10mm, 15mm, 20mm, etc
• Accept that I can’t do a square formation and offset the centre outdoor tile across 50% of the two centre internal ones and keep with a 2mm grout line.

I would really welcome any opinions on the matter. I am so upset that the tiles aren’t the same size but I need to find the best solution. Do you have any other ideas that might work better?

Would it be better to use brush in sanding grout (and a 7mm grout line)? Would that be a better solution?