Rendering Beads and Stop Ends: Corners, Edges and Drips Explained

When people look at render, they notice the colour and texture. What makes it look sharp, and keeps it lasting, are the beads: the thin strips at corners, edges and the bottom of the wall. This guide explains what each bead does, where stop ends go, and why old rusty beads are behind so many render repairs we do.

RCR Connections Ltd is Birmingham based, covering the whole of the Midlands. We fit K-Rend monocouche and silicone render and sand and cement, and our team has 62 years of combined experience. On every job, the beads go on before any render does.

What a render bead is for

A render bead is the thin strip — plastic, stainless or (on older jobs) steel — that forms a straight corner, a clean stop end, a drip above the damp proof course, or a movement joint in external render. People often search the singular “render bead”; on a house we usually fit several types together. The sections below explain each one, and when rusty steel beads need cutting out.

What beads do

A render bead is a thin strip of metal or plastic with a mesh or perforated wing that is fixed to the wall and rendered into. Beads do four jobs:

• give straight, sharp corners and edges;
• set the right thickness of render;
• protect edges from knocks and chips;
• control water at the bottom of the wall and over openings.

Get the beads right and the render looks tidy for years. Get them wrong and edges crack, stain or come away.

Corner beads

Corner beads, also known as angle beads, go on outside corners: the corners of the house, around window and door reveals, and on piers and chimney stacks. They are fixed plumb and straight, and the render is ruled off them. Without a bead, a corner relies on the render alone and can chip and crack easily.

Stop beads and stop ends

A stop bead is used wherever render stops against something else. That might be:

• a window or door frame;
• a brick or stone feature left bare;
• timber cladding, tile hanging or a half-timbered gable;
• the boundary with a neighbour’s house on a semi or terrace;
• under soffits and along the top of the render.

The stop end gives a clean, closed edge rather than a ragged one. Where it meets a window frame, a bead with a small gap lets a sealant line go in, which keeps rain out of the joint.

Bellcast beads above the damp proof course

Along the bottom of the render, just above the damp proof course, goes a bellcast bead. It has a kick, or drip, that throws water clear of the wall below. This is what keeps the render from bridging the DPC, and render should never bridge it. Below the bead, the brick is left showing. Our guide to render and the damp proof course explains why this matters so much.

Bellcast beads are also used over window and door heads, so water drips off rather than running back into the frame.

Movement beads

Render can crack where it is under strain: on long, unbroken walls, where block work meets brick, or where an extension meets the house. Movement beads, also known as expansion beads, let the render move at that line without cracking. Modern render systems tell you where they are needed, and we follow that.

Bead materials

• Galvanised steel. Common on older jobs. It can rust, especially where the render over it is thin or cracked.
• Stainless steel. Does not rust. A good choice outside.
• PVC. Does not rust, comes in colours to match the render, and is widely used with K-Rend monocouche and silicone render systems.

We use stainless or PVC beads outside, to suit the system and the colour.

Rusty beads: a common problem

Many houses rendered twenty or thirty years ago have galvanised beads. As they rust, they swell. That cracks the render along the corner, leaves orange stains running down the wall, and can push the render off in strips.

The fix is to cut back the render along the bead, take the old bead off, fit a new stainless or PVC bead and make good. On sand and cement that is painted, the repair can blend in well. On through-coloured K-Rend monocouche, a repair can show a little, so sometimes it makes sense to redo a whole corner or elevation. Our render repairs page explains how we approach this.

How we fit beads

1. Set out. We mark lines for the bellcast above the DPC, corners and stops, so everything lines up.
2. Fix. Beads are fixed with render dabs or the right fixings, plumb and level, and checked with a level along their length.
3. Check thickness. For K-Rend monocouche, beads are set for about 18 mm of render, which is scraped back 2 to 3 mm to leave at least 15 mm.
4. Render. The render is worked into the bead wings and ruled off the bead noses.
5. Seal. Joints at windows and doors are sealed once the render has cured.

Our K-Rend monocouche page explains thickness and scraping in more detail, and our sand and cement rendering page covers that system.

What to check on your own render

• Orange or brown stains at corners and edges.
• Cracks running straight down corners.
• Render coming away in strips along an edge.
• Render running into the ground with no bead at the bottom.
• Missing or split sealant around frames.

Any of these are worth a photo. Our guide to signs your render needs repairing covers other faults, and our K-Rend in Birmingham and Solihull page explains a full job.

Beads on pebbledash cover-overs and extensions

When old pebbledash is rendered over, the new render sits further out from the wall than before. That means new beads at every corner and edge, and often new window sill extensions so the sills still throw water clear. On new extensions, beads let the new render line up neatly with the old house, and a stop bead or movement bead at the joint lets the two parts move a little without cracking. Our extension rendering page covers this.

Rusty beads or broken render edges?

We work Monday to Friday 7am to 5pm and Saturday 7am to 1pm, and we are closed on Sundays. RCR Connections Ltd is Birmingham based, covering the whole of the Midlands. You can see the towns we cover on our plastering areas and rendering areas pages, and finished jobs on our projects page.

More guides: Render and the damp proof course · Silicone render cleaning and care · SBR, PVA and primers