gyvlon floor and I am the bad boy!

[jonnyc]

thanks

that may explain some readings i have had as well.
do you think that there is a better meter than the ball one that is not too expensive or is the ball one fine.

QUOTE=Ajax123;633632]Three things spring to mind

How long was the floor box left on the floor before reading the moisture? The usual reason for this happening is tha the. Is has been left too long on the floor and it has built up a micro climate inside the measuring chamber underneath. They should usually be left for no more than 72hours. Any longer than this and you get interstitial condensation problems such as those you are seeing.

The other other thing that can cause itis if the box is read to soon. They should really be left on the floor for indium 24 hours to reach equilibrium. Unfortunately the ball ones say read after 4 hours. This is not lon enough. The reason for this is that we are dealing with such low moisture contents. It takes a while for the chamber to equilibrate. So you ge a reading of say 85% at four ours which tells you there is moisture there but not how much (typically it wold be aout 1% which is next to other) then it is left overnight and the system equilibrates to 92% (whichis about 1.5%) moisture. Throw n a few temperature and atmospheric variables and the whole thing is upskittled. If it is below 75% itis much drier at aout 0.3 to 0.5% and responds more slowly to atmospheric changes.

So with floor boxes it needs to be minimum 24 hours maximum 72 hours. If you have not read it within this time it will not be accurate.

If itis below 85% ( not 85% or below!!) then it could be tiled with one of the gypsum adhesives althoughi would always take two readings personally to corroborate each other one at 2 hours and a second at 48 hours.

Of course as I said three things spring to mind... The third is that it might simply not yet be dry...

Clear as mud I know... Ay wpquestions see me after the lesson.. 🙂[/QUOTE]

 

[Ajax123]

Unfortunately jonnyc the ball type is the most widely available and so most cost effective. They are temperature sensitive as they work using a ceramic plate conductor. Nt perfect by any means. In Europe the accepted method is the carbde bomb but one of these would sting in excess of 300 quid. They are more accurate though. With practice electronic meters can be interpreted but these ar even more expensive.

I am happy to say though that if used correctly the hygrometers are usually no trouble.

 

[Gazzer]

Well that makes a total mockery of the instructions given and no wonder there are failures !
The client is getting more and more upset and I am losing money by having to travel to the job to do this test.

 

[Pebbs]

Ajax,

I need a lesson to, I get so confused with this Gyvlon screeds, that I am ending up making a quick exit of site when questioned about them..

Pebbs

 

[The D]

I hereby declare this type of sub floor to be unfit to receive tiling. I am also declaring war on the manufacturers and the installation company’s for this product. :smilewinkgrin:

 

[Ajax123]

I hereby declare this type of sub floor to be unfit to receive tiling. I am also declaring war on the manufacturers and the installation company’s for this product. :smilewinkgrin:

That of corse is despite the hundreds of thousandsf square meters that have been tiled without issue.

Good luck with that mate. One of the strangest things I see is that in France alone there are around 6million square meters of gyvlon type screeds laid and around 85% of these are tiled in smaller domestic situations similar to most of the guys on here. They have almost zero failures. No one will claim there are no failures at all but there are so few that they are pretty insignificant. Germany is similar although n a smaller scale and holland have actually introduced legislation which favours these types of screeds. What is different about the UK. I think it is dinosaurs (or is that Deanosaurs) no offence intended 😉 ... Who refuse to move with the times. These screeds are not going away and will oly increase in the domestic market with the same veracity that they have done in the contract market. The companies who supply them oh supply a demand in the market. If you would like to try and stifle the demand you will be looking to taken not only some f the largest construction companies in the world but also the tens of thousands of small builders, screeders,plasterers, floor layers, self builders, plumbers, heating engineers, environmental lobbyists, health and safety lobbyists who are all moving slowly but inexorably towards a flowing screed preference. I also hear people say builders ony use it cosits cheaper or quicker. These are not always true and in the vast majority of cases cost and speed do not even enter the equation becoming incidental behind all the other considerations builders and contractors have to take account of.

Adhesives have become available much more widely in the last few years. You often say you are being treated as a guinea pig doing all the testing but actually mostof the testing has been done already. I hear often from tilers phrases like "i always use this manufacturer and have never had a prolem" or "This is the best adhesive and primer". Phrases which are bandied about without apparent regard for the nature of thesubstrate and the application in question. What we seem to be incapable of grasping in the uk is that the adhesive that you have always used may not always the best adhesive for these screeds. The best adhesives tend to be Portland cement free...yet we still maintain our adherence t the British Standards because these say cement is best...Just cos the British standards say it does not make it fact.

 

[Ajax123]

Ajax,

I need a lesson to, I get so confused with this Gyvlon screeds, that I am ending up making a quick exit of site when questioned about them..

Pebbs

What do you need to know Pebbs. When I get back to work I will be happy to meet up with you somewhere, buy you a coffee and a bacon butty and go through these screeds in detail. There is not really that much to it. There are four basic steps from the tilers point of view.

1. Is it dry
2. Is it clean and free from excessive dust and contamination
3.Is it heated (if yes it must be comissioned first in ALL cases)
4. Is it sound i.e. cracked, soft or broken. If so does it need any special treatment eg. Ditra, levelling compound, crack repairs etc.

Select your adhesive based on impartial and sensible advice (my suggestions wold be go with gypsm adhesive or, cement free adhesive before going for one based n cement. If cement it must be go for an epoxy primer in reference to usng an acrylic primer.

Also always bear in mind that Gyvlon is only one manufacturer amongst numerous who supply in the uk. I will be starting work for Francis flower limited in the very near future which is a direct competitor to Gyvlon.

 

[Ajax123]

Well that makes a total mockery of the instructions given and no wonder there are failures !
The client is getting more and more upset and I am losing money by having to travel to the job to do this test.

They are not my instructions mate. I can oly say it how it is based on experience and testing in the lab. There is really no reason why the client should not do the test themselves itis hardly rocket science. I often Recomend to clients tha they buy themselves a hygrometer for 80quid which in the overall cost of a build is peanuts. The canteen test the screed and tell you when it's dry. Really that is how it should be in my opinion anyway.

 

[The D]

I will be happy to tell all the poor sods that have had a problem that it is ok as they are insignificant

 

[macten]

Most customers I've met haven't got a clue if it's a Gyvlon screed or not.