Cracked Grout

[natalie stanley]

Good morning

I'm hoping somebody can help and give me a good honest opinion.


May last I had my kitchen tiled. The subfloor is 18mm ply with ditra.

Shortly after the floor was finished around a month later I noticed a crack in the grout running horizontally by the back door. It seems to coincide with where the ply underneath meets. The tiler said it wasn't abnormal to have cracks. It hasn't got worse but I am curious to understand why it's happened. By the doors to the back door part of the floor is concrete. I have photos to show the they didn't ditra over the concrete so half the tile is on concrete and the other on play and ditra. The crack is running a along the grout line after that tile. Thoughts? Another tiler seems to think it's because they didn't ditra over the concrete.

At the other end of the kitchen there are cracks running along the grout where the grout meets the old wooden stairs. I'm particularly concerned by this as the tiled floor directly where the cracked grout is make a little creaky noise when walked on. Not all the time but sometimes. I'm not entirely sure if it's the old stairs creaking or the ply underneath. Having looked online it says that sanded caulk should be used when grouting next to wood.

I have had the tiler who carried out the work back around however he thinks the cracks aren't a sign of anything bad but of course he would say that. He seems to think an old house such as mine has movement which could cause cracks in the grout..

Any thoughts you can share would be greatly appreciated. I've attached some pictures so you can see how the cracks look and may help you advise..

Thanks in advance

Nat

 

[J Sid]

Should have been an expansion / movement joint at intersection of wooden floor and concrete.
Should have been a movement joint round perimeter of room, silicon joint.
Both cases, tiler error
Floor creaking equals movement, floor was not correctly prepared before tiling, was ply fix correctly? Was joints solid enough? Or has something moved after tiling was finished?

 

[Bill]

Not abnormal to have grout cracks where there is large movement - like against doorways. Simple solution would be to replace the cracked (not really cracked but moved) joint with a good quality mastic.

 

[natalie stanley]

Should have been an expansion / movement joint at intersection of wooden floor and concrete.
Should have been a movement joint round perimeter of room, silicon joint.
Both cases, tiler error
Floor creaking equals movement, floor was not correctly prepared before tiling, was ply fix correctly? Was joints solid enough? Or has something moved after tiling was finished?

Should have been an expansion / movement joint at intersection of wooden floor and concrete.
Should have been a movement joint round perimeter of room, silicon joint.
Both cases, tiler error
Floor creaking equals movement, floor was not correctly prepared before tiling, was ply fix correctly? Was joints solid enough? Or has something moved after tiling was finished?

Not abnormal to have grout cracks where there is large movement - like against doorways. Simple solution would be to replace the cracked (not really cracked but moved) joint with a good quality mastic.

Should have been an expansion / movement joint at intersection of wooden floor and concrete.
Should have been a movement joint round perimeter of room, silicon joint.
Both cases, tiler error
Floor creaking equals movement, floor was not correctly prepared before tiling, was ply fix correctly? Was joints solid enough? Or has something moved after tiling was finished?

The tilers did the subfloor, strengthened it too but I dot have pictures of that particular area of subfloor whilst it was being done. As I said I can't tell if the creaks are coming from the floor or stairs. I have a builder friend (who's very experienced) and he seems to think the creaks are coming from the stairs.

If I replace the cracked grout where the stairs and tile meet, with caulk would that not work? I've read online that, that should be used between wood and tile..

Thanks

 

[J Sid]

Not chalk but a good quality silicon to match grout colour.
If the floor is moving this may still give problems later with tiles coming loose. High foot fall area at base of stairs

 

[Bill]

Yeah, use a good caulk though.

 

[natalie stanley]

Not abnormal to have grout cracks where there is large movement - like against doorways. Simple solution would be to replace the cracked (not really cracked but moved) joint with a good quality mastic.

Thanks for your reply - can you clarify what you mean by movement 'like against doorways' there's a set of 3 stairs that lead from the tiled floor to the hallway. Obviously us walking on the stairs could have an impact on the grout cracking? A builder friend who came to look said he thought the creaks were coming from the stairs. They're old pine stairs so it's not unusual for there to be some Movement..

 

[natalie stanley]

Not chalk but a good quality silicon to match grout colour.
If the floor is moving this may still give problems later with tiles coming loose. High foot fall area at base of stairs

The tilers did the floor, if it's moving surely they're responsible? The invoice for the job says the work is guaranteed so surely they are responsible to silicone/grout as a first step to fixing the problem?

 

[Bill]

The rise on the first tread, that meets the tile will probably be moving every time you step on it - it is timber and it will be flexing - only fractionally but enough to cause the grout joint to displace. Just replace the grout joint with good quality mastic silicone caulk or whatever you want to call it.

Soudal is my mastic of choice.

 

[natalie stanley]

The rise on the first tread, that meets the tile will probably be moving every time you step on it - it is timber and it will be flexing - only fractionally but enough to cause the grout joint to displace. Just replace the grout joint with good quality mastic silicone caulk or whatever you want to call it.

Soudal is my mastic of choice.

Thanks

Thanks Tom will try and see how we get on.

 

[Time's Ran Out]

You will always get movement between different materials especially at the edges where skirting would normally cover this.
Your builder has suggested it's the stairs that's moving so not a tiling issue.
A good honest opinion - If the photos are the worst of the problem then a tube of silicone will alleviate your worries.

 

[natalie stanley]

I hope it's the worst. If I can prove the creak is coming from the stairs I'll be happy. What bothers me, is that the cracks are not just running through the middle of the grout but also at he bottom on the side of the grout, as if the floor tiles are coming away from it..

 

[Bill]

I hope it's the worst. If I can prove the creak is coming from the stairs I'll be happy. What bothers me, is that the cracks are not just running through the middle of the grout but also at he bottom on the side of the grout, as if the floor tiles are coming away from it..

From those photos you have shown, I would not be worried as it looks just like a perimeter movement and not a lateral one that could cause cracks in the tiles. Try not to worry and let your tiler sort it out.

 

[Flintstone]

Grout up to skirting boards is always gonna settle with a slight movement like that, just have him silicone it, job done, if there is no cracks or loose tiles on the floor, stop worrying.

 

[J Sid]

Everyone is assuming there is no bounce or movement on the 18mm ply floor, a bit thin I think if going over joists.
What was the ply fixed to? Joists? Chipboard floating floor?, should the floor make up and the possibly of bounce not be ruled out first!
If there is to much movement / bounce in the floor then the first sign of problems would be perimeter cracking at high foot fall area's such as doorways and base of stairs.
Floor may, and I hope it is, be well layed and fine, with just a bit of cracking between tile and wood, which should have been a movement joint anyway.
But if its not, best to find out now before builder / tiler disappears.

 

[Bill]

Julian. I think you are over playing this. You are making this tiler sound like a cowboy.

 

[J Sid]

You are probably right Tom
I do not intend to make him sound like a cowboy, just after more info.
The tiler may well have done a top job and done every bar the perimeter by the book and everything is good.
But when I see 18mm ply and no movement joints around the perimeter alarm bells start ringing for me.
If Natalie can confirm the complete floor make up and there is no bounce or movement in the floor and it is not as I think it is, then I will go back and hide under my stone

 

[Bill]

One more point, these are the only cracks, so far, after 9 months of tiling?.... next to the busiest part of the floor....ie swinging on the stair posts as you go up and down.... looks like a normal family house to me!

 

[J Sid]

Yes Tom, it has been a while since its been finished, and agree that if its only these perimeter cracks then all should be fine. I was only after more information re make up of floor before I would say 'all's good and there should be no more problems down the road'
Trouble is, I have seen 18mm ply over joists fail many years down the line due to moisture/damp getting in from under the floor.

 

[natalie stanley]

Hi all thanks for your replies so far.

The stairs that meet cracked grout - there's only 3 of them and so no stair posts to be swinging from.

Just to give you some background - I first had the floor done in october 2013 by a builder who did lots of other work for me. To cut a long story short, he didn't do a good job with the subfloor so the whole floor had to come up. He hadn't screwed the ply down enough and cracks started to appear in the tiles.

I then got the whole thing done again, this time using professional tilers who were fully aware of my previous disaster.

The tilers strengthened the sub floor themselves putting in additional noggins and laying ditra on top on the ply.

Around a month later I noticed a crack running horizontally across the grout right next to the back door to the garden. I was told it was nothing to worry about by the tiler.

Recently (a month ago) I spotted another line of cracked grout, this time by the stairs. This one is worrying me the most because I can determine if the creak is coming from the stairs or floor.

The cracked grout in this area is getting worse I'm guessing and hoping because we walk up and down those stairs several times a day. Please note there's only 2 of us that live there.

Given what happened previously i would like to think the tilers were extra cautious but I'm obviously a little anxious due to what happened before.

The tiler who did the work came to look at the cracks a few weeks ago and was of course very keen to point out that he had followed building regulations and that he thought it could be movement in the house as it's so old and not unusual for this to happen. I've spoken to other people and my builder friend and he said the joists would and should be independent from the walls therefore movement in the house wouldn't impact the floor.

Just to note, I have a cellar and can see under that part of the floor where the cracked grout/stairs is so will get a torch to it this weekend to have a look.

I truly hope it's just a case of 2 different materials meeting.

Any further advice would greatly appreciated.

Thanks

 

[J Sid]

Thankyou for your reply.
Yes have a look, can you feel the floor bouncing in this area, put a glass of water on floor and walk up and down. Does the water move in glass a little or a lot.

 

[Martyn Leeds]

So all the cracks are only around the edges yeah?
or in the grout lines within the tiling?

 

[natalie stanley]

Thankyou for your reply.
Yes have a look, can you feel the floor bouncing in this area, put a glass of water on floor and walk up and down. Does the water move in glass a little or a lot.

Ok will do this weekend - so a little movement is ok?

Am I right in thinking - the tiler should at least come back and silicone where the cracked grout is?

 

[natalie stanley]

So all the cracks are only around the edges yeah?
or in the grout lines within the tiling?

One is on the edge and the other within the tiles - it just so happens. Directly where the back door is, there is a concrete ledge so the ply starts after this and this is where the crack is. He didn't ditra on top of the concrete. Another tiler seems to think it's because you have 2 different materials meeting underneath the tiles and that it could easily be cured with raking out the grout (where it's cracked) and relaxing with new grout added with Bal ad mix to make it a little more flexible. You can't really see the crack to be honest so visually it doesn't bother me too much, it's just more of what it indicates!

 

[J Sid]

A little movement should be ok.
When in the cellar look at were the floor joints terminated into the wall. There maybe be gaps under the joists at this point which will need filling to stop any movement.

 

[natalie stanley]

The way it's all situated I don't think I'll be able to see where the floor meets the wall..does the position of the cracks within the grout mean anything? Some of the cracks are within the grout line and others at the edge directly where it meets the tile! I just hope the floor isn't sinking

 

[J Sid]

From what you have said I'm sure that a silicon movement joint will sort the problem.
Watch for cracks appearing in the grout joints away from edge.

 

[SJPurdy]

If I understand the posts correctly there are two concerns:

Firstly the cracked grout between the tiles and stair riser. The joint between tiles and perimeter should be a flexible joint particularly when using something like Ditra that allows for lateral (sideways) movement in the tiling, and particularly when the perimeter is something that itself can move (eg wood). As already suggested removing the perimeter grout and replacing with silicone rubber (or other (some can be painted on/up to better)) sealant should solve this. It should be possible to achieve a better looking joint than the existing grout. I would not recommend using decorator's caulk for this.

Secondly by the back door there is a concrete threshold, the ply wood floor butts up to this, the ply is covered with Ditra and then the Ditra and concrete have been bridged with tiling and a grout line is cracking (slightly). This is more incorrect as the tiling should not bridge the two substrates. As already stated a movement joint should have been used. As a grout line is cracking then maybe (you are lucky and) this aligns with the change in substrate and if this grout was also removed and replaced with a flexible sealant it would act as a movement joint.

Using flex grout or grout with flexible additive is not a substitute for using a flexible sealant. Such flex grouts have greater adhesion to the sides of joints and are a little more robust than standard grouts to cope with more stressful situations, but they are no where near as flexible, compressible, stretchable as an appropriate flexible sealant.

 

[natalie stanley]

If I understand the posts correctly there are two concerns:

Firstly the cracked grout between the tiles and stair riser. The joint between tiles and perimeter should be a flexible joint particularly when using something like Ditra that allows for lateral (sideways) movement in the tiling, and particularly when the perimeter is something that itself can move (eg wood). As already suggested removing the perimeter grout and replacing with silicone rubber (or other (some can be painted on/up to better)) sealant should solve this. It should be possible to achieve a better looking joint than the existing grout. I would not recommend using decorator's caulk for this.

Secondly by the back door there is a concrete threshold, the ply wood floor butts up to this, the ply is covered with Ditra and then the Ditra and concrete have been bridged with tiling and a grout line is cracking (slightly). This is more incorrect as the tiling should not bridge the two substrates. As already stated a movement joint should have been used. As a grout line is cracking then maybe (you are lucky and) this aligns with the change in substrate and if this grout was also removed and replaced with a flexible sealant it would act as a movement joint.

Using flex grout or grout with flexible additive is not a substitute for using a flexible sealant. Such flex grouts have greater adhesion to the sides of joints and are a little more robust than standard grouts to cope with more stressful situations, but they are no where near as flexible, compressible, stretchable as an appropriate flexible sealant.

Thanks for your reply here - I'm a little confused by your recommendation for the cracked grout by the back door. Could you please explain again? If we're to take out the existing grout, what should I replace it with? Thanks!

 

[natalie stanley]

Thankyou for your reply.
Yes have a look, can you feel the floor bouncing in this area, put a glass of water on floor and walk up and down. Does the water move in glass a little or a lot.

Have done the water test and not much bounce or movement in the water. The cracks have got worse - do you think it sounds like the movement in the stairs causing the cracks?