M
Merlin5
Hi all. New here. I'm not a DIY person but I'm going to have a go at removing some grout (I bought a grout rake today) and either re-grouting, or using silicone. I've just spent a small fortune on my flat over the last few months, (kitchen, bathroom, central heating, windows, etc) with a new bathroom installed from scratch by a builder, (back to the brick work and new stud wall) including new sand and cemented brick walls, hardiebacker water resistant boarding and then tiling. The grouting on the vertical line right in the corner between the tiles of two walls at right angles to each other and going from ceiling to bath had hairline cracked grout. The shower unit is on the wall to the right of the cracked grout line. My builder said to me he'd re-grout it and said it would crack again, as if to suggest it's natural for this to happen. I've no idea why he was saying this with such confidence instead of suggesting a way to actually prevent it. So he re-grouted, but made a pigs ear of it. Not only has it cracked again but he used the wrong grout. The grout is ivory but where he's redone it it's gone dark grey. There's also excess on the ceramic tiles that has also run some way into adjoining horizontal grout lines which I'm going to have to scrape off. He redid the porcelain floor tile grouting in places too and again, I had to scrape off excess grout which had hardened. At least he used the right grout this time. Lesson learned : never use a general builder to do tiling and grouting. Jack of all, master of none. Uneven tile spacing and some lipping in my 60 x 60cm porcelain kitchen floor tiles too. Yeah, pretty shoddy tbh. 
I've been doing some research and it seems that unless there's absolutely no movement at all, that caulking is better than grout in corners where there's a change of plane because it flexes. Is that true? Now, is caulking basically the same as bathroom silicone, like the stuff around the sides of my bath? I went out and bought a replacement bag of ivory coloured BAL microflex grout today from topps tiles (3.5kg, smallest they have), the same grout used for the rest of my bathroom. But now I'm wondering if I should not use it and go buy some caulk/silicone instead? If so, I'd want to buy some to match the colour of my ivory grout, which is in fact, kind of beige coloured really. Silicone would be easier to apply too wouldn't it and would possibly look as nice?
Here's pictures to show you what it looks like, perhaps it'll help you give me a better idea of what I need to do? One photo shows the corner of the new plasterboard ceiling with a typical hairline crack for new plaster. That crack seems to follow through to the grout cracking. Perhaps that's making the grout crack, or maybe it's just general bath movement? I've really no idea.
Many thanks.
I've been doing some research and it seems that unless there's absolutely no movement at all, that caulking is better than grout in corners where there's a change of plane because it flexes. Is that true? Now, is caulking basically the same as bathroom silicone, like the stuff around the sides of my bath? I went out and bought a replacement bag of ivory coloured BAL microflex grout today from topps tiles (3.5kg, smallest they have), the same grout used for the rest of my bathroom. But now I'm wondering if I should not use it and go buy some caulk/silicone instead? If so, I'd want to buy some to match the colour of my ivory grout, which is in fact, kind of beige coloured really. Silicone would be easier to apply too wouldn't it and would possibly look as nice?
Here's pictures to show you what it looks like, perhaps it'll help you give me a better idea of what I need to do? One photo shows the corner of the new plasterboard ceiling with a typical hairline crack for new plaster. That crack seems to follow through to the grout cracking. Perhaps that's making the grout crack, or maybe it's just general bath movement? I've really no idea.
Many thanks.
