Ewi job

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allyb

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Got an ewi job coming up, I'm familiar with OCR and acrylics but not over insul, Ino you give it a coat of OCR then bed in the mesh then a second coat when this is dry but wondered does this first coat need any primer for the second coat?

Cheers lads
 
Mate your a long way off on that someone will come along and advise you soon stick with it, if you know what your doing ,it,s a peace of ....
 
allyb said:
Got an ewi job coming up, I'm familiar with OCR and acrylics but not over insul, Ino you give it a coat of OCR then bed in the mesh then a second coat when this is dry but wondered does this first coat need any primer for the second coat?

Cheers lads
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what are you talking about, ocr ?
 
yeah got an insulated render job, used both ocr and acrylics been told to give it a wipe over with ocr and bed the mesh in, then when this is dry put on another coat of ocr followed be primer and acrylic when dry is this right?
 
allyb said:
yeah got an insulated render job, used both ocr and acrylics been told to give it a wipe over with ocr and bed the mesh in, then when this is dry put on another coat of ocr followed be primer and acrylic when dry is this right?
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i think someones pulling your chain and no its not right.
 
Just another option for you to think about. Our base coat Parex Miate Monocomposant 30kg can be used as a base coat and an adhesive for the insulation. As faqr as im aware Weber OCR is a base coat and needs to be used with a top coat, therefore OCR meaning One Coat Render doesnt really work.
 
R as a base coat onto Insulation as this is the first time ive ever heard this being used in this way, and i have been working with render of over 7 years now. Im not one for putting down a competitors product, but i dont think this is the way it should be used. We have full details of insulated render systems on our website, or feel free to contact me on here.

Regards

Luke Pickford
Parex
 
owls said:
yes im fully aware what ocr is you joker, you just dont have a clue what your on about.
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Well that's why im on the forum asking some questions, customers bought all the mats from a company called le rock iv never heard of um, just wanted to know what the method is to go over insulation
 
PAREXGROUPUK said:
Just another option for you to think about. Our base coat Parex Miate Monocomposant 30kg can be used as a base coat and an adhesive for the insulation. As faqr as im aware Weber OCR is a base coat and needs to be used with a top coat, therefore OCR meaning One Coat Render doesnt really work.
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No Luke, Weber OCR isn't just a base coat that needs topping but a stand alone one coat render for a traditional float finish. And I thought the force was supposed to be strong with you.
 
allyb said:
Well that's why im on the forum asking some questions, customers bought all the mats from a company called le rock iv never heard of um, just wanted to know what the method is to go over insulation
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well where did ocr come from! the material that you have got to use is le rock iv ! if you have not had any training in ewi then it best leftto someone else.
 
My local build centre phoned me up and asked if you could go straight onto insulation as the rep at a particular firm said this was ok, manager didn't think it sounded right so called me to confirm, so it's no surprise that alley has been given dud info
 
I was under the impression it was the same gear, or similar? Iv used systems like this before so I'm pritty confident, so it's the base coat with mesh in followed by the top coat them primer then acrylic?
 
i wont give you any more clever dick replies,
just does my head in you see so many chancers about that are clueless and dont have the first idea but think ill tackle that.
once youve insulated with mechanical fixings etc, youve then got your base coat with a mesh fully incorporated, left to stand and firm up.then a tight coat of you base coat sponged up trowled/spated up tight, so it is cock on flat. then your primer. then your top coat of acrylic.
its crucial that your second coat of base is spot on otherwise your storing up problems with your acrylic at a later stage particular if your using a 1mm grain as its very unforgiving.
 
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The base coats for insulation are the flexi tile adhesive type renders like parex maite not the heavy OCR, mono types. They ain't sticky, light or flexible enough to reliably cover the insulation boards.
 
there will be secondary fixings, there may be thermo rend, there could be different types of scrim, there will be stress patches, there are different types of finish. this is why you need someone trained with each system they are all different and expensive to correct.
 
warriorupnorth said:
My local build centre phoned me up and asked if you could go straight onto insulation as the rep at a particular firm said this was ok, manager didn't think it sounded right so called me to confirm, so it's no surprise that alley has been given dud info
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unbelievable.
 
malc said:
there will be secondary fixings, there may be thermo rend, there could be different types of scrim, there will be stress patches, there are different types of finish. this is why you need someone trained with each system they are all different and expensive to correct.
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indeed, which was what i was kind of getting at,theres a fair bit to it, and thats before setting up your base rails etc
 
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Cheers owls iv done acrylics before and thin coat renders just not these ewi systems, done a lot of work for this guy in the past and we've just finished up f/set 300m2 on an extension on his house now he wants the outside in this render iv explained to him iv never done it but he won't use anyone else, picked up most of the 'new' renders quick and to a high standard, bringing in a new lad with the gang who says he's used this system just wanted to grab the basics off you boys so I know if he's chatting s**t
 
allyb said:
Cheers owls iv done acrylics before and thin coat renders just not these ewi systems, done a lot of work for this guy in the past and we've just finished up f/set 300m2 on an extension on his house now he wants the outside in this render iv explained to him iv never done it but he won't use anyone else, picked up most of the 'new' renders quick and to a high standard, bringing in a new lad with the gang who says he's used this system just wanted to grab the basics off you boys so I know if he's chatting s**t
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sounds like he is.
 
PAREXGROUPUK said:
R as a base coat onto Insulation as this is the first time ive ever heard this being used in this way, and i have been working with render of over 7 years now. Im not one for putting down a competitors product, but i dont think this is the way it should be used. We have full details of insulated render systems on our website, or feel free to contact me on here.

Regards

Luke Pickford
Parex
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OCR wont work on insulation its specifically for masonry backgrounds ans is no where near polymeric enough to stick long term.

stick with adhesive coat render allyb - still pre bagged around three times the price of ocr but for good reason - it works

try Parex maite as mentioned above or Knauf Marmorit's sm700
 
If you are going to use weber top coat then I would recommend using weber base as well it's not OCR you need,but weber lac is the correct base coat to use over insulation
the order in which you do it is quite simple really
coat of weber lac with mesh bedded in ,another coat of lac and sponged up nice and flat,then 2 coats of primer ,once dry top coat
 
Just to elaborate on Putz advise, your reniforced polymeric base must be as near to perfect as you can get it. A poorly renderered base will be accenuated in the acrylic top coat , resulting in a poor final aeshetic ( look sh*t).

We have found using Weber LAC ... apply a 3mm base over ,bed in mesh, apply another 3mm ( or to beads),then rule through to the best of your ability, do not sponge this but wait till picked up ( fingerpush should only leave a tiny small indent when pushed into 2nd coat of LAC).

Then apply a very thin wet skim of the LAC, do this as neatly as you possibly can, as if you are putting on a 2nd coat skimming over hardwall, nice and tight and neat. Once this starts picking up, gently sponge over .When dry, one good coat of primer if a light colour, two if you feel the primer still looks washy. Remember the Weber top coat is air drying so avoid applying in direct sunlight or in windy conditions. There is no margin for error with top coating, be organised and plan your labour well on larger areas keeping a wet edge at all times.
 
mark ross said:
Just to elaborate on Putz advise, your reniforced polymeric base must be as near to perfect as you can get it. A poorly renderered base will be accenuated in the acrylic top coat , resulting in a poor final aeshetic ( look sh*t).

We have found using Weber LAC ... apply a 3mm base over ,bed in mesh, apply another 3mm ( or to beads),then rule through to the best of your ability, do not sponge this but wait till picked up ( fingerpush should only leave a tiny small indent when pushed into 2nd coat of LAC).

Then apply a very thin wet skim of the LAC, do this as neatly as you possibly can, as if you are putting on a 2nd coat skimming over hardwall, nice and tight and neat. Once this starts picking up, gently sponge over .When dry, one good coat of primer if a light colour, two if you feel the primer still looks washy. Remember the Weber top coat is air drying so avoid applying in direct sunlight or in windy conditions. There is no margin for error with top coating, be organised and plan your labour well on larger areas keeping a wet edge at all times.
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weve just done some acrylic using 0.5 grain.:RpS_scared: ive never trowelled/sponged up a base coat up before as much to an inch of its life.
 
Sounds more like an anti slip polymeric roofing membrane to me . You must of sweat a bit in the stress department getting than one right.

Who's system was you using ?
 
Weber do a base coat called LAC specifically for preparing insulation boards Your explained method sound right its just the product info sounds confused.
 
Yeah got the products mixed up me thinks! Is it best to leave the mesh coat to fully dry out and then apply the top coat?
 
Dependant on what material you are using, you should really put a 5-6mm base coat with mesh bedded in. Make sure the mesh is in the outer layer of the base coat, this is due to strength. Leave it a mm per day for drying. Then put your primer on. This should be on for 24 hrs before top coat goes on. I would not advise sponging your base coat to get it flat, this is due to weakening the base coat by adding more water to it when you sponge. Hope that helps
 
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