new thermal block

[Theoldeduke]

The grey celcon ones, whats the crack with sand and cement render on these. All internal. I know the mix will be weaker but what bonding sdhesive should/can be used.

Thanks

 

[johniosaif]

Sand cement lime mix I would use is 6/1/1. Fibres in the mix also, sbr the block work the day before, 3/1 sbr water.

 

[Arti]

kept it weak

 

[malc]

which celcon blocks are you talking about?
the solar blocks with the figure s impressed on to them i would hardwall and set.
the ones with no key i would dot and dab.

 

[malc]

Sand cement lime mix I would use is 6/1/1. Fibres in the mix also, sbr the block work the day before, 3/1 sbr water.

i do not like sand, cement and lime floating, you end up with high suction and srinkage.

 

[Theoldeduke]

 

[johniosaif]

i do not like sand, cement and lime floating, you end up with high suction and srinkage.

We have done lots of it, not so much now, but as we do mainly refurbs we are inclined for this mix where new meets old

 

[essexandy]

The grey celcon ones, whats the crack with sand and cement render on these. All internal. I know the mix will be weaker but what bonding sdhesive should/can be used.

Thanks

As Arti said keep the mix fairly weak, ratio depends on your local sand. With the sand I use about 7:1 is perfect, I don't use lime on internals and you definitely don't need any sort of bonding agent.

 

[spunky]

i do not like sand, cement and lime floating, you end up with high suction and srinkage.

do you not use waterproofer malc?

 

[carlos]

I would use waterproofer purely to control suction when setting.

 

[malc]

We have done lots of it, not so much now, but as we do mainly refurbs we are inclined for this mix where new meets old

we have also used it sand cement and lime floating loads of times, we purchased the lime already mixed with the sand direct from the pit, we just added the cement. you had to time when to turn back and set to late and the suction would be high.

 

[johniosaif]

we have also used it sand cement and lime floating loads of times, we purchased the lime already mixed with the sand direct from the pit, we just added the cement. you had to time when to turn back and set to late and the suction would be high.

How long would you leave it before skimming normally?

 

[malc]

do you not use waterproofer malc?

waterproofer is ok in a floating coat of sand and cement, i have never tried it in a sand cement and lime floating coat.

 

[spunky]

You don't use lime with it mate it acts as a plasterciser

 

[malc]

How long would you leave it before skimming normally?

all depends on the blockwork or backing. you get opposite suctions when you set, ie low suction block on floating high suction on set. and high suction on floating low suction on set.
on average you would not want to leave sand, cement and lime more then a couple of days. which we know is not long enough for the floating coat to srink back. that is why it has been supersede with hardwall.

 

[malc]

You don't use lime with it mate it acts as a plasterciser

we are talking about two different things. setting sand cement with waterproofe is simple.
setting sand cement and lime you cannot leave the floating to dry out.

 

[johniosaif]

all depends on the blockwork or backing. you get opposite suctions when you set, ie low suction block on floating high suction on set. and high suction on floating low suction on set.
on average you would not want to leave sand, cement and lime more then a couple of days. which we know is not long enough for the floating coat to srink back. that is why it has been supersede with hardwall.

Yes, the 5 day wait to skim (cure) is difficult .

 

[spunky]

Malc are you using this on returns or new block?