New render on existing pebble dash painted Exterior walls. Help

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Jonny Vee

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This may sound stupid but my exterior wall in pebble dash painted over the years looks old and wondering if this can be over covered with new render without removing the pebble dash as seem very strong and would be a mess to remove it first.

Any experience tips advise would be highly appreciated.
 
there are several types and manufacturers of modern renders.
But to do what you want the process is fairly standard.
A plastic mesh has to be bedded into a scratch coat, and finished with a top coat.
Seriously expensive these days.
The product depends on what colour , type of substrate, finish and whether you’d use mineral , acrylic or silicone render.
You should check you tube for parex . monocouche, krend .
and check their websites. they are very informative.
 
Godwasaplasterer said:
there are several types and manufacturers of modern renders.
But to do what you want the process is fairly standard.
A plastic mesh has to be bedded into a scratch coat, and finished with a top coat.
Seriously expensive these days.
The product depends on what colour , type of substrate, finish and whether you’d use mineral , acrylic or silicone render.
You should check you tube for parex . monocouche, krend .
and check their websites. they are very informative.
Click to expand...

Hi Thanks for coming back to me

I won't be a pain but need more specif info as want have it a go as soon as spring come in.

Starting from the point of view that I won't spend a fortune but on the same time looking for a product that can last for a good chunk of year. What would suggest between mineral, acrylic and silicone render?

You talk about plastic mesh bedded into a scratch coat but there is no mention of how to stick the scratch coat to the existing painted render. Any mesh or primer looks like we are relying on the paint to hold everything here.

Thanks
 
I don’t and havent used a lot of it as I don’t like the stuff or cover up jobs.
The last whole house I did was parex . parmurex.
That was on unpainted dry dash .
To cover painted dash you’d need to mechanically fix the mesh to the wall and bed it in the scratch coat . There’s no magic primer or adhesive in this instance as if the paint comes off everything comes off.
I’d probably suggest krend silicone but you really should give them a ring. They’re tech people are spot on.
Bear in mind you’ll get no guarantee from the product manufacturer when rendering over dash or other renders .

You could also sand/cement render over but that’s another story.
 
Godwasaplasterer said:
I don’t and havent used a lot of it as I don’t like the stuff or cover up jobs.
The last whole house I did was parex . parmurex.
That was on unpainted dry dash .
To cover painted dash you’d need to mechanically fix the mesh to the wall and bed it in the scratch coat . There’s no magic primer or adhesive in this instance as if the paint comes off everything comes off.
I’d probably suggest krend silicone but you really should give them a ring. They’re tech people are spot on.
Bear in mind you’ll get no guarantee from the product manufacturer when rendering over dash or other renders .

You could also sand/cement render over but that’s another story.
Click to expand...


Any thought on the EWI system with insulation board mechanially fixed to the wall and then coated ?

https://ewipro.com/2020/06/19/two-ways-to-cover-over-pebbledash/

What about sand and cement it may sound cheap. Do you mechanically fix a metal mesh to the wall and then scratch coat?
 
EWI is the obvious solution but i didn’t mention it as it’s even dearer.
sand/cement is the cheapest option but you’d either have to get the paint off or fix eml to the wall. there are also bonding agents and sbr slurries you could use for both sand/cement and thin coat renders but I wouldn’t fancy it on a whole house.
 
Godwasaplasterer said:
EWI is the obvious solution but i didn’t mention it as it’s even dearer.
sand/cement is the cheapest option but you’d either have to get the paint off or fix eml to the wall. there are also bonding agents and sbr slurries you could use for both sand/cement and thin coat renders but I wouldn’t fancy it on a whole house.
Click to expand...

Paint off will not come out unless you sandblast the facade and does not seems a good idea to do it. Would you suggest eml fix to the wall and then 2 coats of sand cement? is this a lasting job or at some point it may detached from the facade and start cracking? and with a single crack more water egress could make it even worst?

Is the Ewi system a much better solution and long lasting one? material price are out of sky based o their website at moment, Front and back wall are not that big as mostly covered by large windows as this should get rid m2 of material needed.
 
Jonny Vee said:
Would you suggest eml fix to the wall and then 2 coats of sand cement? is this a lasting job or at some point it may detached from the facade and start cracking?
Click to expand...
for me Its as labour intensive as hacking off and doing it properly. But yes if the mesh is fixed soundly and prep is good and you get a consistent good mix and good weather it could last decades.
ewi is much better as a cover up, plus you get a warmer house. Not my favourite concept I must admit.
But, you can pick materials up cheap if you keep your eyes peeled .
 
Godwasaplasterer said:
for me Its as labour intensive as hacking off and doing it properly. But yes if the mesh is fixed soundly and prep is good and you get a consistent good mix and good weather it could last decades.
ewi is much better as a cover up, plus you get a warmer house. Not my favourite concept I must admit.
But, you can pick materials up cheap if you keep your eyes peeled .
Click to expand...

I`m intrigued bu the Ewi for the only reason of making house warmer as this is 1930. Not sure how 20mm of insulation can improve the situation but I`sure it would be better than nothing
 
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