Description
This roll is Ceresit CT 325, the glass-fibre mesh Henkel makes for the reinforced layer of its own external wall insulation systems. It is bedded into a Ceresit mortar over the insulation boards and holds the base coat together under the render finish. It sits in the Renders World reinforcing mesh range next to one Atlas roll.
The Ceresit CT 325 Glass-Fibre Mesh on One Roll
Ceresit CT 325 is an alkali-resistant glass-fibre mesh of 160 g/m², woven to a 4.0 x 4.0 mm grid and sold on a roll 110 cm wide and 50 m long, according to the Ceresit technical data sheet C_CT325_TDS_1_0819. The roll is dark green and printed with the Ceresit logo, so a lap or a corner strip that has gone missing shows up before the base coat closes over it.
- In the wall — the mesh spreads stress across the base coat, so movement at board joints and knocks at low level are carried by the reinforced layer instead of reaching the render.
- In the hand — the gauze weave locks the grid so it does not shift while it is trowelled in, and Ceresit lists the mesh as slipproof and tearproof.
- In the system — Ceresit CT 325 is the reinforcing mesh of the Ceresit Ceretherm insulation systems.
Data Sheet Figures
| Property | Ceresit CT 325 |
|---|---|
| Base | E-glass fabric, gauze weave |
| Weight and grid | 160 g/m² treated fabric, 4.0 x 4.0 mm mesh square |
| Threads | warp 24x2 per 100 mm, weft 22 per 100 mm |
| Tensile strength, standard condition | 2075 N/5cm warp, 2180 N/5cm weft |
| Tensile strength after 28 days in 5 % NaOH | 1195 N/5cm warp, 1220 N/5cm weft |
| Elongation | below 3.3 % lengthwise, below 2.7 % across |
| Roll | 110 cm wide, 50 m long |
| Amount required | approx. 1.1 m of roll per m² of wall |
| Colour | dark green, printed with the Ceresit logo |
| Storage | dry, -10 °C to +50 °C, standing upright, free from pressure |
The two strength rows are not two ways of saying the same thing. The first is the new mesh; the second is the mesh after 28 days in a 5 % sodium hydroxide bath, the alkaline test behind the alkali-resistant rating. When comparing Ceresit CT 325 with another roll, compare the same row on both sheets.
How Many Rolls to Order
The 55 m² in the product name is the area of the roll itself, 1.1 m by 50 m. It is not the area of wall one roll covers, because every strip laps the next. Ceresit gives the amount required as approx. 1.1 m of roll per square metre of wall:
- One roll — 50 m ÷ 1.1 m/m² = about 45 m² of facade.
- On top of that — a little for the diagonal strips at window and door corners, and the extra area of any plinth that takes a second layer.
How It Is Bedded In
Ceresit sets out the method on the same sheet. Spread the prepared Ceresit reinforcing mortar evenly over the boards with a notched trowel of 10 to 12 mm teeth. On mineral wool boards, give the boards a thin priming coat of the same mortar first.
- Lay the mesh straight into the fresh mortar and bed it in with a steel trowel, smoothing as you go.
- Lap each new strip over the last by about 10 cm.
- Keep the edges of the strips away from the joints between the insulation boards, so a lap never sits on a board joint.
- At the corners of openings such as windows, bed an extra piece of mesh about 20 x 30 cm on the diagonal.
- Finish with the mesh fully embedded: properly laid, it is not visible in the surface of the mortar.
The whole reinforcing layer, from base coat thickness to the order of work around reveals, is covered in the base coat and mesh layer guide, and the laps alone in the mesh overlap guide.
Plinths and Walls That Take Knocks
For facades or plinths that will take higher mechanical loads, Ceresit prefers one of two answers:
- Ceresit CT 325 in two layers — the route on this shelf. The area that gets it takes a second run of mesh, and a base coat thick enough to bury both layers.
- A heavier 330 g/m² mesh — not part of this range.
The diagonal strips at openings are the other half of the same job: the guide to why render cracks shows the cracks that start at window and door corners and how the reinforced layer is built to stop them.
Which Mortar It Goes Into
The sheet places the mesh in Ceresit reinforcing mortars. On this shelf that mortar is Ceresit adhesive and basecoat ZU, which bonds the boards and carries the mesh in one product.
- Over EPS insulation boards — the mortar bed goes straight onto the boards.
- Over mineral wool slabs — the priming coat of mortar comes first.
- Other adhesives — the EPS basecoat range lists the rest; keep the mesh and the mortar from the same maker.
The European Technical Assessments listed on the sheet, such as Ceretherm Impactum and the Universal EPS and MW systems, belong to each complete system, not to the mesh on its own.
This Roll or the Atlas Roll
Renders World stocks one roll from each maker. Choose the roll by the system, not by the weight. A Ceresit build-up takes this roll, bedded in a Ceresit mortar. An Atlas adhesive and render build-up takes the Atlas 150 mesh, bedded in an Atlas mortar.
| Roll | Weight | Roll size | Covered area stated by the maker |
|---|---|---|---|
| Ceresit CT 325 | 160 g/m² | 1.1 m x 50 m | about 45 m² (approx. 1.1 m of roll per m²) |
| Atlas 150 | 150 g/m² (-3/+10 %) | 1.0 m x at least 50 m | not stated on the Atlas sheet |
The Ceresit sheet prints strength, grid and elongation figures that the Atlas sheet does not, so the two rolls cannot be ranked on strength from their own documents.
Storing the Rolls
Ceresit asks for the rolls to be kept:
- dry;
- between -10 °C and +50 °C;
- standing upright and free from pressure.
Ordering, Delivery and Returns
- Dispatch — Renders World processes orders the same day when the stock is there.
- Delivery — the cost is not calculated at checkout: after the order, the team contacts you with the most cost-effective option. Small parcels up to 25 kg go next day, and every delivery is kerbside.
- Returns — change-of-mind returns run to 14 days in original condition; goods bought under a 5, 10 or 15 % promotion stand outside that return.
Questions About Ceresit CT 325
Does one roll cover 55 m² of wall?
No. 55 m² is the area of the roll. With the laps Ceresit allows for, one roll covers about 45 m² of wall.
What weight is this mesh?
160 g/m² treated fabric weight, on a 4.0 x 4.0 mm grid.
Can it be used on mineral wool?
Yes. Ceresit asks for a priming coat of the reinforcing mortar on mineral wool boards before the main bed and the mesh go on.
How much should the strips overlap?
About 10 cm, with the laps kept clear of the joints between the insulation boards.
When does it go on in two layers?
On facades and plinths exposed to higher mechanical loads, where Ceresit prefers two layers of this mesh.
Technical Documentation