• Light to medium weight units
• Manufactured from selected FBA & other lightweight materials
• Available, solid, cellular and hollow forms
• General purpose all round performance units
• Work Face 440mm x 215mm
• Strengths 2.9 - 17.5 N/mm2
• Standard material for plastering / rendering
• Close texture for walls built fair or painted
• Standards BS EN771-3 and associated test standards

Description
A general purpose masonry unit of low to medium density, available in strengths from 2.9N/mm2 to 17.5N/mm2. The standard unit has a textured face providing a good key
which is ideal for plastering, dry lining and rendered finishes.

Interlyte Close Textured units are manufactured for walls built fair or painted.
The colour of this unit is light to dark grey.

Manufactured to BS EN771-3 and associated test standards.

Applications
Interlyte masonry units are suitable for the following uses:-

Below level DPC (BS 5628 pt 3 2001) soil classifications 1, 2 & 3, in 7.3N/mm2 strength
units. Internal partition walls, load and non-load bearing.
Outer and inner leaves of cavity walls, some additional insulation required.
Load bearing walls, masonry units available up to 17.5N/mm2 strength, suitable for construction up to 5 storeys depending on design.
Infill units for use in conjunction with concrete beam floors.
Close textured units for walls built fair or painted.
Hollow units for walls requiring lateral force and retaining walls with vertical reinforcement in cores.
Separating / party walls, Building Regulations ADE 2000, see heading Sound Insulation.

Format and Size
Available in Solid, Cellular and Hollow format, also reveal blocks for 50 and 75mm cavity closing. Units made to special order for larger cavities.
Face work size is 440mm x 215mm
Tolerances as EN771-3 Table 1, EN 772-16 Category D1.
Unit Length and height +3 -5mm
Unit Width average +3 -5mm

Physical Properties
Relationship Density/Strength (Solid Units)
EN 772-13 : Gross Dry Density - Category II materials
2.9N/mm2 1250 kg/m3
3.6N/mm2 1350 kg/m3
7.3N/mm2 1450 kg/m3
10.4N/mm2 1475 kg/m3 (to special order)
17.5N/mm2 1475 kg/m3 (to special order)

Design Properties
Modulus of Elasticity
Static modulus of Interlyte masonry is approximately
10kN/mm2.

Thermal Movement
Coefficient of linear expansion of Interlyte masonry is 8 x 10-6/0 c

Moisture Movement
As tested To BS EN 772-14 : 2002
Total movement = 0.37 mm/m

Water Absorption by Capillarity
Test method EN 772-11 - No performance determined

Durability against freeze thaw
No performance determined Not to be exposed

Shear Bond Strength
Declared Value 0.15N/mm2 BS EN 998-2 Annex C

Water Vapour Permeability
EN 1745 : 2002 Table A3 Water vapour diffusion
coefficient μ 5/15

External Walls
Mass of inner leaf to be a minimum of 120 kg/m2. This is easily achieved using a
100mm wide Interlyte 3.6N mass of wall 140 kg/m. Solid units no finish.

Thermal Resistance at 3% Moisture Content 'R' m2 K/W
Assessment of Lamda values based on CIBSE Guide A 1999.


NOTE: Unit thickness of 75mm is omitted at 7.3N/mm2 strength and above, due to
slenderness ratio, as at this and higher strengths can not be justified in load calculations (the
wall would buckle). Resistance Values of blocks for Cellular and Hollow format have been produced by
computer using calculations procedure for voided material in CIBSE Guide 1999.

Sound Insulation
The table below provides design guidance for the estimated sound reduction values of walls constructed of Interlyte masonry units. Data is based on the mass law.
The Frequency range is 100-3150 Hz. The density range for Interlyte material is
1250-1475 kg/m3.



Acoustic Sound Absorption Coefficients
The following data is based on Approved Document Amending Part E, The Building Regulations 2000.



Thermal Conductivity (Standard Values)



Product Range Table

Concrete Density in the range 1250-1475 kg/m3

( ) figures in brackets laid weights including mortar (9.88 units per sq.m). All data based on
equilibrium moisture contents. Reveals to close 50 and 75mm cavity widths are available.
Units to close other cavity widths are available on request. BS EN 1996-1-1 Categorises
units according to void percentages. Cellular Units Group 1, Domino & Hollow Units Group 2.
Any block in excess of 20kg reference should be made to H.S.E. manual Handling Guidelines.

Separating Walls
Approved Document A.D. Amending Part E The Building Regulation 2000
Wall Type 2.2 Interlyte units with strengths of 3.6N/mm2 or more,
in two 100mm leaves, 225 Coursing, min cavity 75mm, 13mm
lightweight plaster on both walls complies with the minimum mass per unit area
incl plaster of 300 kg/m2.

Wall Type 2.3 (for use only where step or stagger of at least 300mm is used).
Specification identical as Wall Type 2.2 with exception of finish which is plastered.
Minimum mass per unit are required of 290 kg/m2. Interlyte units of 3.6N/mm2
strength or more comply. Units to have a density range of 1350-1600 kg/m3.

Approved document E 2000 require separating walls in new buildings to be subject
to pre-completion testing, it details constructural practice, specifically at junctions,
to assist the satisfactory compliance of sound insulation standards for cavity
separating walls.

Building Regulations have issued a document of Robust Standard Details to be used
as an alternative to pre-completion testing, strict adherance to the construction
details therein is intended to solve the issue.

Fire Resistance
Interlyte masonry units are manufactured from Class 1 natural aggregates
and are classified as non combustible in accordance with with
‘Euroclass A1’.EN ISO 1182.
The table below shows the resistance periods based on
BS 5628: Pt 3: 2000 Table 16 Notional
Fire Resistance of Walls (no finish).