using ply on a timber frame for rendering

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adevans

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Hello All,
I've had a good look at all the discussions about rendering on to a timber frame and was wondering if you can help me.
Currently the back wall of the building i am working on is wet, wet , wet.
The current render onto lath has daylight cracks in it and i've advised the owner that the whole lot needs to come off and be re-done. All the windows need repair and a lot of the timbers are rotten. I've had advice that i don't need to ply it, just wire it and render it but i've seen a lot of people say to use ply.

I was thinking of insulation on internal and using paper, baton, emi then render. Does this sound right. I'm not a plasterer / renderer but i am in charge of the job and want to get it done right.

Thanks in advance for any help.
 
I would use a carrier board then base coat/mesh/ texture.this is the best system to use IF your plasterer is familiar with this.
The other way would be ply/paper/rib lath then 3 coats of sand & cement
 
adevans said:
Hello All,
I've had a good look at all the discussions about rendering on to a timber frame and was wondering if you can help me.
Currently the back wall of the building i am working on is wet, wet , wet.
The current render onto lath has daylight cracks in it and i've advised the owner that the whole lot needs to come off and be re-done. All the windows need repair and a lot of the timbers are rotten. I've had advice that i don't need to ply it, just wire it and render it but i've seen a lot of people say to use ply.

I was thinking of insulation on internal and using paper, baton, emi then render. Does this sound right. I'm not a plasterer / renderer but i am in charge of the job and want to get it done right.

Thanks in advance for any help.
Click to expand...

what age is your property? i have a picture of a georgian timber framed property. is it a listed building?
 
adevans said:
Thanks for your replies. Which Ply, is shuttering okay or should it be marine ply?
Click to expand...

neither, you need exterior quality ply.
you need a better quality glue then shuttering ply, but you do not need the finished quality of marine ply
 
Thanks Malc, It is a victorian building, we took the internal lath and plaster down and all we have now is a thin lath and render with a lot of cracks. Didn't shuttering ply used to be waterproof glue? The last exterior quality ply i used on a trailer was rubbish and split within a year, even with a coat of resin. I'm currently of the thought that i need to ply onto the frame. butt jointed. can you get ply with insulation backing?
then building paper, overlapped by 100mm, then vertical batons 300mm centres, then building paper again, then EML (stainless) overlapped by 280mm, then 3 coats render,
3:1
4:1,
5:1 - have seen 5:1:1 is this an addition of lime? (hydrated)
With waterproofer in first two coats.
@Runwithscissors and @church - thanks for your previous posts on this subject, i have been avidly reading them.

Question though - What do i use for fixings of the above and do i need to sort out drainage holes or something similar…I haven't done this before and i'm getting someone in to render it but that is all he is going to do!

Does this all sound the correct way?
Thanks
 
Last edited by a moderator:
adevans said:
Thanks Malc, It is a victorian building, we took the internal lath and plaster down and all we have now is a thin lath and render with a lot of cracks. Didn't shuttering ply used to be waterproof glue? The last exterior quality ply i used on a trailer was rubbish and split within a year, even with a coat of resin. I'm currently of the thought that i need to ply onto the frame. butt jointed. can you get ply with insulation backing?
then building paper, overlapped by 100mm, then vertical batons 300mm centres, then building paper again, then EML (stainless) overlapped by 280mm, then 3 coats render,
3:1
4:1,
5:1 - have seen 5:1:1 is this an addition of lime? (hydrated)
With waterproofer in first two coats.
@Runwithscissors and @church - thanks for your previous posts on this subject, i have been avidly reading them.

Question though - What do i use for fixings of the above and do i need to sort out drainage holes or something similar…I haven't done this before and i'm getting someone in to render it but that is all he is going to do!

Does this all sound the correct way?
Thanks
Click to expand...

Hi There adevans

Have a look at the brochure in my signature below, with regards to Knauf Aquapanel Exterior

your project sounds a little bit more complicated than the norm - existing building, removal of current, etc......

if you have more details, e mail them to me [email protected] and we will be able to advise and assist further....

or give me a call on 07918766577

All the best

Richard Lord
 
adevans said:
Thanks Malc, It is a victorian building, we took the internal lath and plaster down and all we have now is a thin lath and render with a lot of cracks. Didn't shuttering ply used to be waterproof glue? The last exterior quality ply i used on a trailer was rubbish and split within a year, even with a coat of resin. I'm currently of the thought that i need to ply onto the frame. butt jointed. can you get ply with insulation backing?
then building paper, overlapped by 100mm, then vertical batons 300mm centres, then building paper again, then EML (stainless) overlapped by 280mm, then 3 coats render,
3:1
4:1,
5:1 - have seen 5:1:1 is this an addition of lime? (hydrated)
With waterproofer in first two coats.
@Runwithscissors and @church - thanks for your previous posts on this subject, i have been avidly reading them.

Question though - What do i use for fixings of the above and do i need to sort out drainage holes or something similar…I haven't done this before and i'm getting someone in to render it but that is all he is going to do!

Does this all sound the correct way?
Thanks
Click to expand...
hi we are ply cladding an extension this week prep for us to render. exterior ply 12. mm £20 +vat. then tyvek breathable membrain £40 per roll off ebay, the stainless steel rib lath £21 + vat penlaws.
tyvek is a better job the building paper, you need rib lath, not eml as rib lath is lifted away from the ply so that the render can get behind the lath therefore a good key for the render. eml fits flat against the ply therefore the render does not get a good key.
we fit the rib lath with stainless nails. i have never left any breather holes on this type of work. for insulation between the studs we use the foil backed one from jewsons which is the cheapest one that we can find. £20 for an 8x4 sheet. 10mm thick.
we find this method quicker then the render carrier board method.
 
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'not eml as rib lath is lifted away from the ply so that the render can get behind the lath therefore a good key for the render. eml fits flat against the ply therefore the render does not get a good key.

Thanks @malc, we were going to put the eml onto the batons over tyvek to provide a gap. I'm not sure if this method is any different than using rib lath except you don't have the extra materials / time of putting up batons…

And thanks for the suppliers info. i shall definitely go for Tyvek.

Does anyone know of any other advantage of either method?


 
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adevans said:
'not eml as rib lath is lifted away from the ply so that the render can get behind the lath therefore a good key for the render. eml fits flat against the ply therefore the render does not get a good key.

Thanks @malc, we were going to put the eml onto the batons over tyvek to provide a gap. I'm not sure if this method is any different than using rib lath except you don't have the extra materials / time of putting up batons…

And thanks for the suppliers info. i shall definitely go for Tyvek.

Does anyone know of any other advantage of either method?
Click to expand...
go for rib lath, fitting eml on batterns could cause problems for your renderer. if the gap is to big it would take to much material to prickup [first coat] eml only needs to be fitted on batterns about a quarter on an inch thick, no more. if you go fore eml you need tyvek, then batterns then tyvek again then eml. eml is a no brainer, use rib lath, ply, tyvek, rib lath then render.
 
adevans said:
and thanks @runwithscissors but i think i'm going to be going with the ply / mesh method.
Click to expand...

No Problems

On an exisiting building you are probably right

Boarded systems are cheaper and easier - when you know how to do it, as I am sure guys on here will agree - but with S&C the lath method is probably better

good luck
 
Your saying about using battens , ply it all , then cut strips of ply which will work as your battens , as roofers lath etc to wide as said :-) just a way we have done it for a builder before
 
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