Metal trims are used as opposed to using timber to form angles, stops and bell casts in render finishes. Metal angle beads, screed beads, casing beads etc are all metal trims that are used in plastering.
Stainless steel or plastic trims should be used for external work. Metal trims should be cut with tin snips.
There are 4 different types of trim used for external rendering.
Bell beads are used to create a drip above windows and doors.
Stop beads are used to form panels by being fixed up to timber frames.
Angle beads are used to strengthen corners.
Expansion beads are used when two walls meet at a straight joint to allow some movement.
These trims all come in plastic and stainless steel and can all be fixed using rustproof nails or by wedging them in position with the render, making sure they are straight with no bows as these will show in the finished render.
Metal angle beads are made from sheet of galvanised steel and come in different sizes. between 2.4 m and 3 m.
Thin coat beads are used on external angles for work that is in thin coats. They come in different sizes from 2.4 m to 3 m and can be 3 mm thick or 6 mm thick.
Plaster stop beads are used for protection on places such as door openings. They come in different sizes to suit plaster that is 10 mm, 13 mm, 16 mm and 19 mm thick.
Plasterboard edging beads are used for two reasons. They protect the edge of the plasterboard and helps with fixing. They are made to suit plasterboards that are 10 mm and 13 mm.
There are 2 types of architrave beads and come in lengths of 2.300 m and 3.000 m. They are used as a plaster stop around door frames.
External render stop/bell cast stop is used where a stopped end might be needed in external rendering. It made from galvanised steel and is fixed with or nails or it can be bedded. It can be used over window openings for outside rendering.
Screed beads are used when different types of plasterwork are applied to the same surface. It is made from galvanised steel and is available in 3.000 m lengths.
Beads for external use are made of stainless steel. Only certain types of beads should be used outside due to weather conditions.
Corner mesh is used for internal angles. It stops cracks from appearing and is available in lengths of 2.5 m. Corner mesh is EML and is bent at right angles to create wings.
Strip mesh is the same as corner mesh but it does not have wings, it is a flat material. It is used for 2 reasons, as a cover to protect pipes and as a reinforcement strip in plaster work.