Cracked Grout

[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 Silicon 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 Silicon 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 Silicon 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?