Gyvlon LL screed pour.

[DHTiling]

It was a nice day though Al..

 

[Ajax123]

That sounds about right.. what i will say now is Alan, they will not get any joy from them..:mad2:

we had a customer on here the other week, and they got no joy..

But it is worth a try and i just looked and they actually recommend using the qaurtz with UFH...

You probably right sadly Dave......:incazzato:

 

[Ajax123]

It was a nice day though Al..

I got sunburned on me head.......ouch

 

[DHTiling]

I got sunburned on me head.......ouch

would that be the bit where there is no hair..:lol:... bit like me..

 

[Ajax123]

would that be the bit where there is no hair..:lol:... bit like me..

yep. And on me forehead........

 

[DHTiling]

A question Alan..

That first pour i saw had a reading of 225... now when the screeder said it was hard to work , was this just keeping the flow of the level easier because it looked wet as can be to me and looked like it was flowing great.

The next of 240 , i agree did spread better on the test plate but didn't look much better on the flow than the 225 section..

Is this just to keep the screeder from pushing about as much or was he being cautious because of before..?

 

[Ajax123]

A question Alan..

That first pour i saw had a reading of 225... now when the screeder said it was hard to work , was this just keeping the flow of the level easier because it looked wet as can be to me and looked like it was flowing great.

The next of 240 , i agree did spread better on the test plate but didn't look much better on the flow than the 225 section..

Is this just to keep the screeder from pushing about as much or was he being cautious because of before..?

The first test on the third load was 220 flow. The specification criteria is 230 to 270mm. If it is too dry the calcium sulphate element in the screed can use up too muchof the free water reducing bleed which is essential for curing in order to prevent early age shrinkage and thus cracking.

I should have added 70 litres of water to bring it up to mid spec i.e. 250mm. I only added 50mm on the basis that the mix was made using a relatively coarse sand which has a tendency to "hang and prevent flow" which could have explained the relatively low flow test. Adding too much water to a mix with a very coarse sand could cause over bleed and thus potential segregation so on the first water addition I was being cautious due to the issue before. It flowed at 240 after we had mixed it up in the barrel.

As it happens I was perfectly comfortable placing it at the workability we were at but as the screeder took a second reading and it had fallen slightly back to 230 (probably due to the first water addition not being thoroughly mixed in as it is added to the back end of the barrel and can take some pulling through) he decided that it needed extra water. In terms of it being hard work - not sure - Anyway as we had only poured about 2m3 of that load and to give him this bit of "independence" in front of his customer I knew the batch would take another 50 or 60 litres without any issues so agreed with him when he wanted to put in another 20 litres which actually I had missed out of the first addition anyway.

In fact when it was placed reasonably low in the spec it was bleeding out nicely so I would have been quite happy. was generally pretty good stuff apart from the second load which went back.......Graham is one of the good screeders so don't want to upset him or lose his business. Sometimes you have to give a bit to get a lot........ .

It could have stood being quite a bit wetter but I don't think given the type of sand used it would have had little effect on the flow into the slab and was not really necessary IMO.

clear as mud......

 

[DHTiling]

Yep.. clear as a bell..

I did notice on the slab piece outside that the sand was coarse.. a lot coarser than i imagined it would be.. very hard once dry isn't it..

 

[Ajax123]

yep - I normally reckon 4mm to dust or 6mm if it has a high fines content. I reckon that was 6mm but was cruched rock sand with relatively low fines so was not running as well as it could've done. Still was easy enough to place without too much effort.

Sets like fliping bell metal. Nominal C30 which is same as structural grade concrete.

 

[DHTiling]

Deffo..

I can see why these Gyvlon screeds are a damn site stronger.. and can be poured in bigger area's without expansions..

 

[Spud]

does the low laitence screed still need the surface ground and are the polymers in the powder mix or added to the water ?

 

[Ajax123]

does the low laitence screed still need the surface ground and are the polymers in the powder mix or added to the water ?

No Gyvlon need the surface GROUND. They need to be sanded using a floor sander or floor scarifier. I have also used a carborundum block sander in the past.

Old fashioned has a clearly defined skin on the surface maybe 0.5mm deep. This MUST be sanded to remove it prior to priming and tiling.

Low laitance has no skin on its surfac so does not need to be sanded to remove it.

However if ANY screed or concrete is dirty or contaminated in some way then it is best to sand it in order to clean it up before tiling it.

Ergo - All screeds should probably be sanded

There are no "polymers" as such in it.

 

[DHTiling]

Just adding a video to this thread on Gyvlon actually being poured ..





Oh and this job here which i watched poured, i actually got called in to tile it as the tiler who was doing it naffed it up..


[video=youtube;3yF1fXyi9rs]http://www.youtube.com/watch?v=3yF1fXyi9rs[/video]