Render board painting...

[Pocster]

Hey all!

 

It's only a tiny detail but annoys me!. I have to leave a nice gap at the edge of my render board where it meets the soffit.

I bought some trim to hide my sins 

 

As you can see the render board shows through; it would be a pig to cut in situ - and I ain't taking them off.

 

So!; is it ok to paint with say black external masonry paint? - too hide the whiteness popping through.

Just don't want any flaking or anything. Do once; then forget - not sure if render board is 'paintable' .....

 

Cheers

Edited November 20, 2017 by pocster

[Luckylad]

Hi

 I'd  give the board company a call.

 I don't know if you are aware but your board gaps must be filled with mastic to stop the render squeezing into the gaps.

[Pocster]

13 hours ago, Luckylad said:

Hi

 I'd  give the board company a call.

 I don't know if you are aware but your board gaps must be filled with mastic to stop the render squeezing into the gaps.

No

i wasn’t aware . Assume when I get it rendered the guy would tell me that ....

[Luckylad]

Yes hopefully he would say ,but it's just better if it's gone hard before he starts.

You fill with mastic so the render doesn't get in between the boards when they expand and contract. Helps stop any cracking.

[Pocster]

5 hours ago, Luckylad said:

Yes hopefully he would say ,but it's just better if it's gone hard before he starts.

You fill with mastic so the render doesn't get in between the boards when they expand and contract. Helps stop any cracking.

Thanks !

[Pocster]

I guess the mastic has no purpose but to stop the render coming through. So just *any* mastic?

Could I not use expanding foam (if careful!); I have lots of this hanging around!!

 

Cheers

[Jeremy Harris]

8 minutes ago, pocster said:

I guess the mastic has no purpose but to stop the render coming through. So just *any* mastic?

Could I not use expanding foam (if careful!); I have lots of this hanging around!!

 

Cheers

 

The mastic has to stay slightly flexible to deal with expansion and contraction, and I doubt that expanding foam would.  I also think that the render would find it's way into the holes in the trimmed foam, rather defeating the purpose.

[Pocster]

5 hours ago, JSHarris said:

 

The mastic has to stay slightly flexible to deal with expansion and contraction, and I doubt that expanding foam would.  I also think that the render would find it's way into the holes in the trimmed foam, rather defeating the purpose.

Ok 

so just standard ‘bathroom ‘ mastic is fine ?

[Jeremy Harris]

You want standard outdoor building mastic probably.  It's not expensive, but to ensure the render people are happy with it, give them a call and ask what they normally use, as you don't want the mastic to have some unwanted reaction with the render.

[Pete]

I have used moisture resistant render board with a dpc  behind on a wooden batten and I do not need to mastic the joints. My boards can be left for at least 12 months according to the makers spec so check with the render people before you go ahead. If exposed for any length of time they need brushing down and left to completely dry out before rendering.

[Pocster]

Thanks all ; will do. !

[Luckylad]

On 04/12/2017 at 20:44, Pete said:

I have used moisture resistant render board with a dpc  behind on a wooden batten and I do not need to mastic the joints. My boards can be left for at least 12 months according to the makers spec so check with the render people before you go ahead. If exposed for any length of time they need brushing down and left to completely dry out before rendering.

Hi

Who is the manufacturer of your board?

If the joints don't have to have  mastic,then that's one less Job!

[Pete]

Its called multi rend carrier board