Y-Wall

A1 non-combustible, BBA certified calcium silicate cement building board

RCM Y-wall is a high-quality flexible calcium silicate cement based building board, perfect for use as a fire rated sheathing board. Offering excellent fire properties as well as high levels of dimensional stability, Y-wall is an exceptional board for use in multiple applications.

Y-wall is used primarily as a fire rated sheathing board or building board. Used extensively on both steel frame and timber frame structures, Y-wall is used behind all types of façade solutions.

Technical Data

Nominal Density

1200 kg/m3

Bending Strength

((Modulus of Rupture))

12 N/mm2

Modulus of Elasticity

((MoE))

4000 N/mm2

Thermal Conductivity

≤0.23 W/mk

Moisture Content

≤9%

Reaction to Fire

BS EN 13501-1 Class A1 Non-Combustible

Biological Resistance

Highly Resistant

Surface Condition

Front Face - Smooth

Back Face - Textured

Durability

((Life Expectancy - Minimum))

30 years

Standard Board Sizes

2400 x 1200mm

Thickness

((mm))

6, 9, 12, 15

Nominal Mass of Product

((kg/m²))

7.2, 10.8, 14.4, 18

Dimensional Tolerance

Length
±3mm
Width
±3mm
Thickness
±0.5mm

Product Testing and Certification

Fire Reaction Tests
BS EN 13501-1:2018 Class A1
BS EN ISO 1716:2018
BS EN ISO 1182:2020
BS EN 1363-1
BS EN 1364-1
BS EN 1365-1
BS 476 Part 4
BS 476 part 22 fire rated through wall solutions
Physical Properties
BS EN ISO 12467
BS EN 594 Category 1
BS EN ISO 1015-11
BS EN ISO 1062-1
BS EN 594:2011

Recommended Fixing

Steel Frame
FIX006 - 4.8mm x 38mm Wing tip self drilling fixing
Timber Frame
FIX005 - 4.2mm x 42mm Climaseal self drilling fixing

Y-Wall FAQs

What applications can RCM Y-Wall be used in?

RCM Y-wall can be used as an external sheathing board on structures including where a fire rating is required including those greater than 18m in height, where a structure is over 18m in height RCM Y-wall should be used from ground level all the way up the structure.

What is the fire rating of RCM Y-Wall?

RCM Y-wall is rated as A1 non-combustible.

Can RCM Y-Wall be used as a permanently exposed external board?

No, RCM Y-wall cannot be left permanently exposed.

Which way round should RCM Y-Wall be fitted?

RCM Y-wall has one smooth face and one textured face, the smooth face should be fixed outermost.

What should be used to tape the board to board joints?

RCM Dafa tape should be applied to all board to board joints as soon as possible after fixing the boards, unless an airtight seal is required to the external face of the sheathing board, for an airtight seal then the RCM Joint Seal system should be used.

During the construction phase, how long can RCM Y-Wall be left exposed?

If the joints are taped using RCM Dafa tape as soon as the boards are fitted they can be left exposed during the construction phase for twelve months.

What are the fixing edge distance and maximum fixing centres for RCM Y-Wall?

RCM Y-wall edge distance is 15mm except at the board corners where fixings should be moved up or down to achieve 50mm. Fixings should be fixed using a maximum 600mm x 300mm grid pattern.

How many fixings are required for RCM Y-Wall?

27 No. fixings per 2400mm x 1200mm sheet when fixed in a vertical orientation.
25 No. fixings per 2400mm x 1200mm sheet when fixed in a horizontal orientation.

What type of fixings should be used?

For fixing into SFS framing 4.8mm x 38mm self-drilling wingtip fixings suitably treated against corrosion should be used.
For fixing into Timber framing 4.2mm x 42mm self-drilling fixings suitably treated against corrosion should be used.

Can RCM Y-Wall be fixed to a radius?

We have done our own in-house testing for 12mm RCM Y-Wall. The results suggest a radius of 7.5m or greater, however a structural engineer should ratify this for your project. RCM Y-Wall should not be fixed to a radius but should be cut into vertical strips and fixed to form the curve from a series of flat panels.

What blade is suitable for cutting RCM Y-Wall?

RCM can supply Poly Crystalline Diamond (PCD) blades suitable for cutting RCM Y-Wall in a range of diameter and bore sizes, please contact RCM Technical department for further information.