O
Old Mod
So Gary and I have come down to Hastings to inspect a large Porcel-thin floor that is failing.
On seeing the floor for the first time it appears to be laid with care and the fitter, (builders son) appears to have done a half decent job.
But there are issues, a few have cracked and some tiles when walked on, crunch underfoot.
The main areas effected are the high traffic areas in the kitchen diner, so in through the main door from outside, the wc next to it and the main walkway from the kitchen area to the rest of the house. The dining area and utility remain mainly unaffected it seems.
So like all failing areas, investigative work has to be done, i.e. Tiles have to be lifted.
Problem number 1. Retro ufh is directly under the tile.
2. No antifracture or decoupler used.
3. Locating the pipe work.
The ufh system in question is Wundafloor, eps boards (polystyrene) covered with aluminium spreaders.
First thing to overcome was locating ufh pipes so we can safely cut away joints and remove tiles.
Solution, thermal imaging camera.
Pipes located without too much problem.
Then we needed a way of cutting the joints open to free the tile from the rest of the field so that when we chop it out, it doesn't effect the tiles around it.
It seems we found a new use for the sigma Kerra Cut!
Securing the guide rail to the floor we used it as a fence to run a grinder, with a variable depth shroud on it to cut away the joints.
The blade was set for the exact thickness of the tile.
What we found beneath was a floor with around 65-70% coverage at best, and poor troweling technique.
But most disturbing of all was the adhesive had very little strength and was soft and easily scraped from the floor.
The tiles were stuck to it, no doubt about that, but there was just no strength in the adhesive at all, we could crush it between our fingers.
The floor has been down for 9 months, more than enough time to cure completely.
The recommended adhesive is Mapei Kerabond T & Mapei Isolastic stuck direct to the aluminium.
No priming required.
The adhesive used, Ultra S2 single part adhesive.
Priming was required if this adhesive was to be used, unfortunately, it wasn't.
So in normal circumstances you might think that you'd have a half decent chance of the the floor being ok even tho you didn't prime.
Thing is, when aluminium comes into contact with Portland cement, a chemical reaction takes place, this chemical reaction creates hydrogen gas!
What does this mean?
Well in the first instance the adhesive is filled with bubbles of Hydrogen gas, which in turn causes the adhesive to expand considerably causing tension in the floor. Secondary to that, it also causes the aluminium to corrode.
So what you are left with is a floor where the adhesive is literally on the edge of catastrophic failure.
I have some better examples on site I'll post tomorrow.
But as you can see, it looks like overwatered adhesive, but in fact it's cavities caused by hydrogen gas. Causing the adhesive to be almost useless.
We scraped it away from the floor with a bolster by hand!
We are attempting to make repairs to the worse effected areas, but it's a 50/50 chance at best.
So remember, DO YOUR RESEARCH!
All of this could of been avoided if someone had called the relevant tech departments. And all for the sake of a few quid for primer!!
I'll go in to our remedy techniques tomorrow,
I'm too tired right now.
On seeing the floor for the first time it appears to be laid with care and the fitter, (builders son) appears to have done a half decent job.
But there are issues, a few have cracked and some tiles when walked on, crunch underfoot.
The main areas effected are the high traffic areas in the kitchen diner, so in through the main door from outside, the wc next to it and the main walkway from the kitchen area to the rest of the house. The dining area and utility remain mainly unaffected it seems.
So like all failing areas, investigative work has to be done, i.e. Tiles have to be lifted.
Problem number 1. Retro ufh is directly under the tile.
2. No antifracture or decoupler used.
3. Locating the pipe work.
The ufh system in question is Wundafloor, eps boards (polystyrene) covered with aluminium spreaders.
First thing to overcome was locating ufh pipes so we can safely cut away joints and remove tiles.
Solution, thermal imaging camera.
Pipes located without too much problem.
Then we needed a way of cutting the joints open to free the tile from the rest of the field so that when we chop it out, it doesn't effect the tiles around it.
It seems we found a new use for the sigma Kerra Cut!
Securing the guide rail to the floor we used it as a fence to run a grinder, with a variable depth shroud on it to cut away the joints.
The blade was set for the exact thickness of the tile.
What we found beneath was a floor with around 65-70% coverage at best, and poor troweling technique.
But most disturbing of all was the adhesive had very little strength and was soft and easily scraped from the floor.
The tiles were stuck to it, no doubt about that, but there was just no strength in the adhesive at all, we could crush it between our fingers.
The floor has been down for 9 months, more than enough time to cure completely.
The recommended adhesive is Mapei Kerabond T & Mapei Isolastic stuck direct to the aluminium.
No priming required.
The adhesive used, Ultra S2 single part adhesive.
Priming was required if this adhesive was to be used, unfortunately, it wasn't.
So in normal circumstances you might think that you'd have a half decent chance of the the floor being ok even tho you didn't prime.
Thing is, when aluminium comes into contact with Portland cement, a chemical reaction takes place, this chemical reaction creates hydrogen gas!
What does this mean?
Well in the first instance the adhesive is filled with bubbles of Hydrogen gas, which in turn causes the adhesive to expand considerably causing tension in the floor. Secondary to that, it also causes the aluminium to corrode.
So what you are left with is a floor where the adhesive is literally on the edge of catastrophic failure.
I have some better examples on site I'll post tomorrow.
But as you can see, it looks like overwatered adhesive, but in fact it's cavities caused by hydrogen gas. Causing the adhesive to be almost useless.
We scraped it away from the floor with a bolster by hand!
We are attempting to make repairs to the worse effected areas, but it's a 50/50 chance at best.
So remember, DO YOUR RESEARCH!
All of this could of been avoided if someone had called the relevant tech departments. And all for the sake of a few quid for primer!!
I'll go in to our remedy techniques tomorrow,
I'm too tired right now.
