Lose/Broken Grout

[tommyg]

Hi guys. Me again. Some of you answered my question yesterday which i thank you for.

I have a look at my floor again last night. I raked all of the loose grout out of the joints. The tiles do not move. The floor is slightly springy but not too bad.

When i put the grout in my hand it just crumbled into a sandy substance. I am now wondering if i did not mix the grout correctly. I used Unibond Quick Setting Charcoal grout.

Any advice guys?

 

[sWe]

Hi mate.

I'm a bit confused over here. What do you mean with "when I put the grout in my hand"?

 

[tommyg]

Sorry mate. Meant that when i put the grout that i took out of the joints in my hand and squashed it - it crumbled.

Any clearer?

 

[sWe]

Grout is really strong and hard when it's dried in the grout lines (if mixed and applied correctly). Unsupported grout is a bit brittle. If it crumbles too easily, (it's not supposed to crumble from just rubbing it between yer fingers), you've probably either mixed it with too much, or too little water. It needs to be just right, because otherwise it won't cure correctly.

Look, when you prepare to tile onto a floor, you can test the strength and stiffness of the floor by filling a couple of glasses with water to the rim. Place them on the floor, and walk around with "heavy" steps. If the water spills, you need to reinforce the floor.

If the floor flexes, you need to reinforce it, especially if the tiles are large. If you don't there might be cracks in the grout, the tiles, or the tiles might delaminate, etc.

 

[DHTiling]

Hi guys. Me again. Some of you answered my question yesterday which i thank you for.

I have a look at my floor again last night. I raked all of the loose grout out of the joints. The tiles do not move. The floor is slightly springy but not too bad.

When i put the grout in my hand it just crumbled into a sandy substance. I am now wondering if i did not mix the grout correctly. I used Unibond Quick Setting Charcoal grout.

Any advice guys?

Was this (cheap) Unibond grout flexible.......?..... i would use a better make....

Maybe BAL or Mapei or Ardex etc.....

 

[Gazzer]

The grout shouldnt crumble like that especially if you used flexi. I would say it was either too dry or not mixed correctly. I cant say as i am a fan of any Unibond product.
As Dave says try a better grout from the makes he suggest.
From a personal note i cant reccomend Mapei highly enough.
When you say the floor is springy is there any way you could explain just how springy?

 

[tommyg]

Hi thanks for your reply.

When I say the floor is springy I mean that it feels slightly bouncy when I put a lot of weight on it. My plumber said that whoever put the original plumbing in, they cut through joists to get pipes in. This could well be the reason.

I have a good look last night and there are about 4 out of 15 tiles where the grout has come out. I am going to take them up tomorrow and just make sure the ply is fixed down properly.

Can you tell me where i can get Mapie from?

Thanks for your advice its much appreciated.

 

[Gazzer]

Mapei is widely available from tile distributors and shops. It shouoldnt be too hard to find. Cant say where the best place for you to buy would be. Maybe if you updated your profile so we knew which part of teh country you are from.
To be honest it it sounds as if the floor is to springy, regrouting could be a waste of time and money. If you can feel the spring then i would say its too much.