Which bead?

[AKP1]

Hi, My first post on this site. I am a chippy, have been for 30 yrs or so now and am quite familiar ( but by no means an expert) with most aspects of building but am a bit stumped with this one.
I have a bare external wall on my house which needs rendering, the top edge and two sides are straightforward but the bottom edge is where I need some advice. It has a flat roof up against it with the felt coming up it approx 150 mm and then lead flashing chased into the wall and dressed down over the felt. I therefore have a ledge of lead around 25mm wide which the render comes down to. If I do not use a bead and just sit the render on top of the flashing, I am left with a direct horizontal route for water to penetrate over the top of the chased in lead straight into the wall. If I use a normal stop bead, (exterior quality of course), it will leave the same situation. What I could do with is some sort of bead which can fix to the wall, sat on top of the 25mm lead ledge but projects slightly over the lead's vertical face with a profile creating a drip mould, as it were, just something that points down slightly so that water running down the face of the finished rendering, gets caught on the tip of the bead and drips onto the face of the lead rather than travelling back into the wall along the top of it. Thus achieving pretty much the same as a window cill or external door frame, capillary groove.
I have had a look around, had bellbeads suggested but when found, they don't seem to be what I had hoped for. I think I could possibly achieve what I want by using a normal corner bead but then flattening it and just leaving the nose sticking out over the face of the lead but would rather use the correct thing.
Sorry to waffle on a bit but it's not that easy to describe, would be nice to submit a sketch but not sure how to if possible.
Any advice would be most welcome....thanks for reading.

 

[Micilin]

Is this the kind of thing? Drip bead?

In plastic or stainless

 

[CluelessDIYer1]

My apologies to the OP as i can't help, but the response given to you sparked a question for me & i don't think it's enough to warrant a new thread..?

Why are there so many names for beads?

You call the image you showed a drip bead. I work for a builders merchants & i've heard this term before. The bead you show a pic of we actually call a belcast bead.

Then there's the angle bead which some seem to call a roughing on bead.

Then there's the skim bead which i know others have a name for.

Skim stop bead (3mm) - can't remember the other names for this.

Renderstop bead (10mm) - another i've heard different names for.

Many a time we've sent out the 'wrong' beads. Customer will place an order for delivery for x-amount angle beads. We send them angle beads yet they want skim beads.

 

[AKP1]

Hi, Thanks for your responses, I think the stainless bead in the second diagram will be the one, managed to find some in Wickes, (not cheap are they?) so thanks again, I will try to contribute to this site myself, I hope that my twopennyworth may help someone one day as you have.

 

[Micilin]

My apologies to the OP as i can't help, but the response given to you sparked a question for me & i don't think it's enough to warrant a new thread..?

Why are there so many names for beads?

You call the image you showed a drip bead. I work for a builders merchants & i've heard this term before. The bead you show a pic of we actually call a belcast bead.

Then there's the angle bead which some seem to call a roughing on bead.

Then there's the skim bead which i know others have a name for.

Skim stop bead (3mm) - can't remember the other names for this.

Renderstop bead (10mm) - another i've heard different names for.

Many a time we've sent out the 'wrong' beads. Customer will place an order for delivery for x-amount angle beads. We send them angle beads yet they want skim beads.

Oooh - where to start . we have regional names I suppose. And also the actual maunfacturers don't always use the same names as the people who actually use the product. Same with the nonsensical specs we get from time to time form architects (antother thread!)
For example, British Gypsum don't make a bag of 'skim' , or 'stuff' (As in 'do we have enough'stuff'? ' Castle don't make bags of 'Dust' and as far as I know you can't buy premixed bags of 'muck'


OK - rendering beads.

Back in the day we used timbers to work to, and when the beads became more popular we would only use them to hang down over lead flashing.

The bead in the picture above is called a 'bell cast' because the profile of the finished render tradtionally looked like the bottom of a bell ie with a curve.

However, the function of the bead is to make sure that water does not run back into the wall, so it is sloped downwards, which causes the water to 'drip' off - hence 'drip bead' . With timber we would do this with a chamfer. Or when making cappings, with a rope pinned onto the shutter to form a groove when the shutter is removed.

They are also called 'render stop beads' by the manufacturer (NEVER in 40 years have I heard them called that by a plasterer, but maybe in some parts?)

The reason for this is that the render at the upright arris would be formed by an angle bead or timber, and the render did not 'stop' here, but wrap around the corner . It would only 'stop' at the top - where no bead was needed as it butted into a fascia or coping stone etc. Or it would stop by butting into an adjacent wall, again, no bead needed.

So the only place where the render 'stopped' would be at the plinth, and here you if you had a bead -even if it had to form a drip - it was called a 'Render Stop' bead . Looking at the elevation, the only place where the render 'stopped' on the wall was here.

'Stop' beads, however are different entirely. And the people writing the catalogues dont have a clue!



Thincoat angle bead, skimming angle bead are the same

And thincoat stops, skimming stops, 3mm stops are all the same (dont see many 6mm stops since we went to 2mm skim coat)

Floating beads , roughing beads, heavy angle beads,plasterer's bead all the same

Arhcitrave and channel beads MAY be the same, depending.

Any more for any more?[/img]