Don't you think it's odd..

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FreeD

FreeD

Private Member
When I learnt the trade putting waterproofer in the scratch coat was standard, gives you time to float the top coat and allows the top coat to cure gradually...

With these modern renders e.g k rend gp mortar and weber OCR (2 coats), no waterproofer in them, they don't dampen down well, when you top them they dry so quickly you struggle to finish them to a high standard and they micro crack all over the place...

What's the deal why don't they put waterproofing additives in?
 
FreeD said:
When I learnt the trade putting waterproofer in the scratch coat was standard, gives you time to float the top coat and allows the top coat to cure gradually...

With these modern renders e.g k rend gp mortar and weber OCR (2 coats), no waterproofer in them, they don't dampen down well, when you top them they dry so quickly you struggle to finish them to a high standard and they micro crack all over the place...

What's the deal why don't they put waterproofing additives in?
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are they not already mixed in?
 
Done a search can't find what's in it but it does say it's weather resistant whatever that's meant to mean. You have asked a few times about this why don't you just use sand and cement?
 
flynnyman said:
Done a search can't find what's in it but it does say it's weather resistant whatever that's meant to mean. You have asked a few times about this why don't you just use sand and cement?
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Because we machine apply....and then top with silicone thin coat from the same manufacturer.

And no they are not already mixed in if you speak to K Rend or Weber neither product has them mixed in, they are a standard 6.1.1 mix no waterproofing additives.
 
flynnyman said:
Done a search can't find what's in it but it does say it's weather resistant whatever that's meant to mean. You have asked a few times about this why don't you just use sand and cement?
Click to expand...

Because we machine apply....and then top with silicone thin coat from the same manufacturer.

And no they are not already mixed in if you speak to K Rend or Weber neither product has them mixed in, they are a standard 6.1.1 mix no waterproofing additives.
 
FreeD said:
Because we machine apply....and then top with silicone thin coat from the same manufacturer.

And no they are not already mixed in if you speak to K Rend or Weber neither product has them mixed in, they are a standard 6.1.1 mix no waterproofing additives.
Click to expand...
FreeD said:
Because we machine apply....and then top with silicone thin coat from the same manufacturer.

And no they are not already mixed in if you speak to K Rend or Weber neither product has them mixed in, they are a standard 6.1.1 mix no waterproofing additives.
Click to expand...
Maybe they should do two grades one for scratch and one for top but o suppose that defeats the object of why they are doing. Do you prime before you silicone and do you incorporate a mesh?
 
FreeD said:
When I learnt the trade putting waterproofer in the scratch coat was standard, gives you time to float the top coat and allows the top coat to cure gradually...

With these modern renders e.g k rend gp mortar and weber OCR (2 coats), no waterproofer in them, they don't dampen down well, when you top them they dry so quickly you struggle to finish them to a high standard and they micro crack all over the place...

What's the deal why don't they put waterproofing additives in?
Click to expand...
 
Yea we always prime before spraying, you can use Rend Aid or Krend R7. Most of the jobs we do are on Victorian properties, so they require dubbing out (I always prefer to do the dubbing out over the primer) some even need a scratch coat to get it flat before the beads go on.

What would be ideal is a render which can be used for dubbing out or a scratch coat, that can be machine applied and has waterproofing additives in it.

When you apply K Rend GP Mortar over the scratch you are going over a scratch coat with no waterproofer in it...yes its weather resistant like any sand/cement/lime mortar but it hasn't got any waterproofing additives in it. So topping is a nightmare, especially in the heat.

Mesh at stress points Flynn, not the whole wall.

Maybe it's just the case that these products are not designed for re furb, more for new build. Which I rarely do, but when we do we don't have any of these issues.

Does anyone add waterproofer to GP Mortar or Weber OCR?
 
FreeD said:
Yea we always prime before spraying, you can use Rend Aid or Krend R7. Most of the jobs we do are on Victorian properties, so they require dubbing out (I always prefer to do the dubbing out over the primer) some even need a scratch coat to get it flat before the beads go on.

What would be ideal is a render which can be used for dubbing out or a scratch coat, that can be machine applied and has waterproofing additives in it.

When you apply K Rend GP Mortar over the scratch you are going over a scratch coat with no waterproofer in it...yes its weather resistant like any sand/cement/lime mortar but it hasn't got any waterproofing additives in it. So topping is a nightmare, especially in the heat.

Mesh at stress points Flynn, not the whole wall.

Maybe it's just the case that these products are not designed for re furb, more for new build. Which I rarely do, but when we do we don't have any of these issues.

Does anyone add waterproofer to GP Mortar or Weber OCR?
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I add waterproofer to an OCR scratch when it's not suited to one coat. Works at treat Fred. I've had the same issue with fast drying without any WP's so it's got to go in for me.
 
Rossi46 said:
I add waterproofer to an OCR scratch when it's not suited to one coat. Works at treat Fred. I've had the same issue with fast drying without any WP's so it's got to go in for me.
Click to expand...

What waterproofer do you use and how do you gauge it? When you top do you wet in down or straight over?
 
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