Sponge render finish on cement board

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Runswithscissors

Private Member
Loads have used similar products to MS20 onto cement boards….

Almost all do it twice, after it cracks or shells off the first time. They then take it all down and start again using a thin coat render onto a board second time - as they should of done first time around (it’s a learning experience - quite an expensive one)

Cement based renders, like MS20, are for application to concrete, blocks or bricks - all of which should not move and are very strong and stable sub straights

Render boards are usually fixed to substraights that will move, like timber frame, steel frame or SIP systems. These sub straights will move, settle or flex. Cement renders, like MS20 are heavy and brittle and will fail when applied to something fixed back onto flexible substructures

Use a modern thin coat render onto boards - that all the render system suppliers have available…. If you like the finish of FASSAs MS20 render, talk to them about getting a similar finish

Good luck
 

devneydutch

Active Member
I’ve done the house next door in ms20 the customer wants the same sponge finish but the whole house is render board. Do you know of a product that is thin coat but with a sponge finish
Thanks
 

Runswithscissors

Private Member
Not easy to get a consistent sponge float finish using thin coat renders….

Not really my area of expertise, maybe someone here can advise…. I would usually recommend you talk to a contact at your render supplier of choice’s…

….or, explain to the new customer that they have a different system, so will have to consider a slightly different finish!

Another tip… if you have never done a thin coat render… get someone who has working with you to do it!!!

Easy to muck up early on, then hard / impossible to get it back again later…

Good luck
 

Rossi46

Private Member
Fix 10mm beads and use a good polymer modified base coat as a scratch coat. Make sure all joints are meshed before a full mesh.
Then use MS20 over the base.
 

devneydutch

Active Member
Not easy to get a consistent sponge float finish using thin coat renders….

Not really my area of expertise, maybe someone here can advise…. I would usually recommend you talk to a contact at your render supplier of choice’s…

….or, explain to the new customer that they have a different system, so will have to consider a slightly different finish!

Another tip… if you have never done a thin coat render… get someone who has working with you to do it!!!

Easy to muck up early on, then hard / impossible to get it back again later…

Good luck
I’ve done plenty of thin coat just know it’s a different finish. Those 2 house are going be joined up in the middle with glass hallway
 

devneydutch

Active Member
Fix 10mm beads and use a good polymer modified base coat as a scratch coat. Make sure all joints are meshed before a full mesh.
Then use MS20 over the base.
Sounds like an idea just worried about cracking like Runwith was saying as Ms20 is cement based and not designed to go on cement board.

What about treating the board as timber frame and fixing stainless sheet mesh to the cement board?
 

malc

TPF Special Forces
I’ve done the house next door in ms20 the customer wants the same sponge finish but the whole house is render board. Do you know of a product that is thin coat but with a sponge finish
Thanks
The thin coat base coats rub up beautiful with a sponge float.
We work in a gang of 3 on thin coat on aqua panel cement board. As soon as it is ready my youngest son doubles back and sponge up going over it twice. It gives a great finish.
 

devneydutch

Active Member
What base coat are you using
The thin coat base coats rub up beautiful with a sponge float.
We work in a gang of 3 on thin coat on aqua panel cement board. As soon as it is ready my youngest son doubles back and sponge up going over it twice. It gives a great finish.
 

Rossi46

Private Member
Sounds like an idea just worried about cracking like Runwith was saying as Ms20 is cement based and not designed to go on cement board.

What about treating the board as timber frame and fixing stainless sheet mesh to the cement board?
No it’s not made to go directly to the Board that’s bleedin obvious, polymer bases can be rubbed up nice. Not as nice as a none polymer base though.
 

tapit

Well-Known Member
Loads have used similar products to MS20 onto cement boards….

Almost all do it twice, after it cracks or shells off the first time. They then take it all down and start again using a thin coat render onto a board second time - as they should of done first time around (it’s a learning experience - quite an expensive one)

Cement based renders, like MS20, are for application to concrete, blocks or bricks - all of which should not move and are very strong and stable sub straights

Render boards are usually fixed to substraights that will move, like timber frame, steel frame or SIP systems. These sub straights will move, settle or flex. Cement renders, like MS20 are heavy and brittle and will fail when applied to something fixed back onto flexible substructures

Use a modern thin coat render onto boards - that all the render system suppliers have available…. If you like the finish of FASSAs MS20 render, talk to them about getting a similar finish

Good luck
Substrate mate.
 
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