Render advice - beads

EDSPAM

New Member
I have a builder who has been working for me for a number of weeks and he has done a lot of work for me in the past. he is a jack of all trades, very handy guy and we have and receptive to my 'research'.

Due to most of the the house being old and somewhat awkward he advised me to take the render to the ground (same as next door). He also advised me to purchase galvanized beads and that the more expensive stainless were a waste of money. He has now fitted all the beads and scratch coated everything (a large surface area of building and garden walls). He is awaiting my decision on the bell cast before applying the smooth coat.

I have been through some threads and there seems to be mixed feelings about render bridging the dpc but many say not to use galvanized beads externally due to rusting which is very concerning.

Obviously undoing what he has done so far would be a major headache.. i.e. replacing all the existing beads. Also is it ok to fit a bell cast bead on top of a scratch coat?


Advice would be much appreciated.
 
Last edited:

Elite exteriors

Active Member
I have a builder who has been working for me for a number of weeks and he has done a lot of work for me in the past. he is a jack of all trades, very handy guy and we have and receptive to my 'research'.

Due to most of the the house being old and somewhat awkward he advised me to take the render to the ground (same as next door). He also advised me to purchase galvanized beads and that the more expensive stainless were a waste of money. He has now fitted all the beads and scratch coated everything (a large surface area of building and garden walls). He is awaiting my decision on the bell cast before applying the smooth coat.

I have been through some threads and there seems to be mixed feelings about render bridging the dpc but many say not to use galvanized beads externally due to rusting which is very concerning.

Obviously undoing what he has done so far would be a major headache.. i.e. replacing all the existing beads. Also is it ok to fit a bell cast bead on top of a scratch coat?


Advice would be much appreciated.
He knows f**k all about rendering you never bridge the dpc and plastic beads have been around for years they definitely don't rust you're going to make a big mistake letting him carry on
 

essexandy

The Lake Governor
He knows f**k all about rendering you never bridge the dpc and plastic beads have been around for years they definitely don't rust you're going to make a big mistake letting him carry on
Actually that's not quite true. If there is a plinth then the dpc is bridged.
 

EDSPAM

New Member
Spoke to manufacturer tech support and they said Ideally be using plastic (I live 7 miles from the coast) as stainless can still corrode. However they also said that they have seen galv last many years without issue, so its not a forgone conclusion that it will rust. They said it is not as big an issue with sand and cement as there is less exposed bead and any exposed can be painted with a protective paint. Another interesting point is the bell bead we used previously is marked for external use but the corner bead is still marked as internal only (same manufacturer). However looking at the datasheet they are the exact same spec 275g zinc coated.

Spoke to builder again and he has assured me that he has used galv for years in this area without any issues. There is nothing in it for him cost wise as I am buying my own materials. He showed me some walls he had done on the plot last year (unpainted) there was some exposed glav which was rust free. All the garden walls have now been done but the main building is still only at scratch coat.. he said a days work to replace all the galv beads with plastic if I am worried but he doesn't think the glav will be a an issue.

Anyone here used glav without issue?
 

Stevieo

Royal Spin Doctor
Spoke to manufacturer tech support and they said Ideally be using plastic (I live 7 miles from the coast) as stainless can still corrode. However they also said that they have seen galv last many years without issue, so its not a forgone conclusion that it will rust. They said it is not as big an issue with sand and cement as there is less exposed bead and any exposed can be painted with a protective paint. Another interesting point is the bell bead we used previously is marked for external use but the corner bead is still marked as internal only (same manufacturer). However looking at the datasheet they are the exact same spec 275g zinc coated.

Spoke to builder again and he has assured me that he has used galv for years in this area without any issues. There is nothing in it for him cost wise as I am buying my own materials. He showed me some walls he had done on the plot last year (unpainted) there was some exposed glav which was rust free. All the garden walls have now been done but the main building is still only at scratch coat.. he said a days work to replace all the galv beads with plastic if I am worried but he doesn't think the glav will be a an issue.

Anyone here used glav without issue?
I'm glad I don't work for you.
 

Elite exteriors

Active Member
Spoke to manufacturer tech support and they said Ideally be using plastic (I live 7 miles from the coast) as stainless can still corrode. However they also said that they have seen galv last many years without issue, so its not a forgone conclusion that it will rust. They said it is not as big an issue with sand and cement as there is less exposed bead and any exposed can be painted with a protective paint. Another interesting point is the bell bead we used previously is marked for external use but the corner bead is still marked as internal only (same manufacturer). However looking at the datasheet they are the exact same spec 275g zinc coated.

Spoke to builder again and he has assured me that he has used galv for years in this area without any issues. There is nothing in it for him cost wise as I am buying my own materials. He showed me some walls he had done on the plot last year (unpainted) there was some exposed glav which was rust free. All the garden walls have now been done but the main building is still only at scratch coat.. he said a days work to replace all the galv beads with plastic if I am worried but he doesn't think the glav will be a an issue.

Anyone here used glav without issue?
He must be an old boy that's stuck in his way's no one uses galvanized beads anymore they are crap and you definitely don't bridge the dpc
 

Cockney1

Well-Known Member
My 1930s house rendered top to bottom (original) ,it’s bulletproof
1646209029275.jpeg

Still looks great!
(y)
 

spunky

Private Member
How many people have had problems because there bellcast bead is 10mm over the dpc? It’s a load of rubbish it’s practically impossible not too bridge it at some point if people are really that bothered knock the house down and get the brickies to lay the plinths level, as for the galvanised I did my neighbours in Galvanised and it lasted about 10 years but there pretty bad with rust now fortunately he moved and I have a new neighbour, I’d use plastic stainless steel are pretty much redundant know
 

spunky

Private Member
There’s no problems at all with sticking a bead ontop of a scratch coat thats what i did on my garage I floated the plinths it’s easier to do it with the scratch coat he’s just left himself a bit more dubbing out to do and no it’s not a swimming pool or damp?
It’s an old wives tale unless you’re plinths are made of engineering brick if you have a rendered plinth at some point that joint will be bridged you will have kicks on the beads with gaps and if you really think that little bit of 5mm bead at the back will sit perfectly straight directly on the dpc joint even done by the book you’re all dreamers
 

Self Build

New Member
I have a question that might or might not be relevant

An existing garage/shed had a small extension added to the back

The original shed is rendered with a break at the DPC line where a 'step inwards' is formed. I would not call it a bell cast as it is more of a squared off finish rather than a curve.

The plan is to match the new render into the old render along each side and then render across the back of the new part of the building
1648062353790.png
See sketch above.

I am assuming that I would do the following

1.20mm corner beads on the back corners and around openings
2.10mm thick Scratch coat the full distance down to ground level.
3.10mm Stop bead at DPC level placed in front of scratch coat
4.10mm Finish coat down to stop bead
5.Should the finish coat below the DPC line then be only 5mm thereby creating the step?

Does it need a scud before any of this is done? Not sure if I have the room for another coat
 
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