Failed anhydrite floor

[TT Tiling]

sad to see that ,im laying on them floors every week ,with no probs ,dry them out till they are bone dry ,good sealer ,happy days

 

[thompsonbrown]

Looks like primer was laid before screed was dry, Adhesive looks like it took to primer.
Big area for no expansion 2mm spacers?
Could be a number of things. Looks like a total ripout to be safe.

 

[Stef]

I had bother with primer on top of Gyvlon a few weeks back,
That primer looks like a neat coat & has just came away like a skin.
Should only be 1 coat of primer at 3:1.
As you say John, it will be an easy rip out.

 

[John Benton]

I had bother with primer on top of Gyvlon a few weeks back,
That primer looks like a neat coat & has just came away like a skin.
Should only be 1 coat of primer at 3:1.
As you say John, it will be an easy rip out.

That was my thought Stef, don't have a pic of what was left on the floor but I suspect very little of the primer as it's still stuck to the adhesive. As you say the first coat would have probably been sufficient and was a little confused when the screeding contractor had told the builder to put a 2nd coat of neat primer over the top. This would have formed a skin and therefore the probable cause of failure.

 

[Chalker]

That was my thought Stef, don't have a pic of what was left on the floor but I suspect very little of the primer as it's still stuck to the adhesive. As you say the first coat would have probably been sufficient and was a little confused when the screeding contractor had told the builder to put a 2nd coat of neat primer over the top. This would have formed a skin and therefore the probable cause of failure.

Don't know but is it possible to be too dry?? This might absorb all the fluid, thus leaving a skin?

just a thought?..

 

[Stef]

John I used AnhyFix & should have done a test area without primer.
It states a 3:1 coat though.
The tapers had been in taping the ceilings & had dropped (as they do) a fair amount of fast set onto the floor & I was struggling to knock it off with a scraper.
I think we are going to see a lot of failures coming up with Calcium screeds.

 

[Gazzer]

John I used AnhyFix & should have done a test area without primer.
It states a 3:1 coat though.
The tapers had been in taping the ceilings & had dropped (as they do) a fair amount of fast set onto the floor & I was struggling to knock it off with a scraper.
I think we are going to see a lot of failures coming up with Calcium screeds.

Didnt you sand the floor 1st ?

 

[Stef]

Didnt you sand the floor 1st ?

This was before the floor was sanded.
I was tiling the walls at the time & the floor must have been registering + 90 rh at that time.
I couldn't believe how much of a bond it had achieved to the screed.

 

[John Benton]

Just add to this one John, it'll keep all the info in the same place for future reference.

Did it straightaway Bri, can you merge the 2?

http://www.tilersforums.com/tiling-forum/71268-another-floor-failure.html

 

[Ian]

Did it straightaway Bri, can you merge the 2?

http://www.tilersforums.com/tiling-forum/71268-another-floor-failure.html

Just on my way out the door John, I'll do it later. It's easy enough.

 

[the diving tile]

Get a core sample of the floor tested, have come across two floors here where the screed was at fault a bit like tiling on bonding, lime is a pain in the ***

 

[Ian]

Thanks to whoever merged the two threads.

 

[Gazzer]

Thanks to whoever merged the two threads.

 

[Ajax123]

Get a core sample of the floor tested, have come across two floors here where the screed was at fault a bit like tiling on bonding, lime is a pain in the ***

Tested for what??

 

[the diving tile]

Tested for what??

Sand/ binding agents or just to rule out the screed

 

[Ajax123]

Sand/ binding agents or just to rule out the screed

Nope still not with. What tests are you suggesting??and how will those test results "rule out the screed"?

 

[the diving tile]

Nope still not with. What tests are you suggesting??and how will those test results "rule out the screed"?

So your saying the screed cannot be at fault and not to question it at all.

 

[Ajax123]

So your saying the screed cannot be at fault and not to question it at all.

No I'm not saying that at all. What I'm asking is what test are you going to request that a core sample will satisfy and what answers are you seeking in doing such tests. Test for binder/sand. This is petrology and will tell you if sand and binder are present. If the screed is hard there is binder and most likely sand present....

 

[the diving tile]

No I mean for sand quailty

 

[Ajax123]

No I mean for sand quailty

Anhydrite screeds are made in ready mix facilities where they are subjected to quality assurance regimes. The sand used is specially selected and tested for suitability by the binder manufacturers (us). The measure of sand quality is usually determined by how quickly the screed hardens. Ergo you will prove that the sand is of good quality and suitable for inclusion in the screed by doing such a test. We already know the answer before the screed is made. Same with the binder. It is unusual in the extreme for there to be anything aims with the individual components of the screed such that standard statistical process control will take care of things. Add the sand and binder together with water and you have a screed mortar. There really isn't much to go wrong during the manufacturing process itself.

 

[Ajax123]

Anhydrite screeds are made in ready mix facilities where they are subjected to quality assurance regimes. The sand used is specially selected and tested for suitability by the binder manufacturers (us). The measure of sand quality is usually determined by how quickly the screed hardens. Ergo you will prove that the sand is of good quality and suitable for inclusion in the screed by doing such a test. We already know the answer before the screed is made. Same with the binder. It is unusual in the extreme for there to be anything aims with the individual components of the screed such that standard statistical process control will take care of things. Add the sand and binder together with water and you have a screed mortar. There really isn't much to go wrong during the manufacturing process itself.

Most of the issues with screeds of all types are caused not by the screed itself but what people do with it and how they do it....

 

[the diving tile]

Most of the issues with screeds of all types are caused not by the screed itself but what people do with it and how they do it....

Thanks for that , is there any type of pourable floor that does not need sanding and sealing

 

[Ajax123]

Thanks for that , is there any type of pourable floor that does not need sanding and sealing

All screeds should be lightly abraded before applying bonded floor coverings. As for sealing it depends more on the adhesives. Some don't require a primer some do. ALL adhesives based on Portland cement will require a suitable (ideally epoxy) primer.

 

[Dougs Third Go]

from purely a tilers perspective, gypsum threads certainly seem to throw up more problems than solutions, we only seem to get answers ipso facto, ie, latching the stable door after horse has bolted. Alan this is no disrespect to you whatsoever, alone, you have stood your ground and tried to explain, at bloody long length, the merits of anhydrite, but personally the only people I can see benefitting are builders looking for a quick screed.. I'm in the minority have now (having the "know how" now) as to how to prepare and test for a anhydrite screed, but Cap'n Quick and Cheerful, down the road from me will only be to willing to tell customers that I'm talking a load of garbage and he'll do it for half the price....need I add more?

 

[DHTiling]

The only bad thing about calcium screeds is a tiler who does not make sure he/she stands their ground and insist it is dry and prepped correctly , the rest is down to the tiler , get to know the correct way with your chosen adhesive etc..

Simple as that , learn to tile to them successfully or get left behind , blunt but true .

 

[Ajax123]

from purely a tilers perspective, gypsum threads certainly seem to throw up more problems than solutions, we only seem to get answers ipso facto, ie, latching the stable door after horse has bolted. Alan this is no disrespect to you whatsoever, alone, you have stood your ground and tried to explain, at bloody long length, the merits of anhydrite, but personally the only people I can see benefitting are builders looking for a quick screed.. I'm in the minority have now (having the "know how" now) as to how to prepare and test for a anhydrite screed, but Cap'n Quick and Cheerful, down the road from me will only be to willing to tell customers that I'm talking a load of garbage and he'll do it for half the price....need I add more?

I ain't gonna give up.... They'll neverrrr tak ooor freedom.... And all that.

To be fair though I have seen step changes for the better over the 10 years or so I've been dealing with these screeds and things are probably a million times better than they were when I joined the forums.

 

[The Legend; Phil Hobson RIP]

I always ask the question "what type of screed is this?" after attending Alan's course in Durham, I realize how hard it is to distinguish the anhydrite from sand and cement just by looking at them.

I think the key is to find out who laid the screed, and what is it?

 

[Ian]

I always ask the question "what type of screed is this?" after attending Alan's course in Durham, I realize how hard it is to distinguish the anhydrite from sand and cement just by looking at them.

I think the key is to find out who laid the screed, and what is it?

I always ask now, even if I think I know what it is. Anhydrite is normally easy to spot with all the foam barriers around the perimeter. It has a yellowish colour as well.

 

[Dougs Third Go]

I always ask the question "what type of screed is this?" after attending Alan's course in Durham, I realize how hard it is to distinguish the anhydrite from sand and cement just by looking at them.

I think the key is to find out who laid the screed, and what is it?

as do I Phil, but most, won't ask as they've never heard of it, thus just assume it's normal concrete screed, and the rest, as they say, is history

 

[Dougs Third Go]

I always ask now, even if I think I know what it is. Anhydrite is normally easy to spot with all the foam barriers around the perimeter. It has a yellowish colour as well.

Bri, that's a given with a concrete screed, ie perimeter expansion joint.