Whole life costing: School partitions

Peter Mayer

Schools can be a tough and demanding
environment for partitions, as they must reist
mistreatment and perform to a high standard.
Peter Mayer of BLP discusses at the options.

The former Building Schools for the Future programme had over £2bn earmarked for long-term investment in secondary schools. Guidance for their construction is contained in the government publication the Standard Specifications, Layouts and Dimensions (SSLD) for school buildings.

It is hoped these notes will standardise schools, which will mean faster design and construction, reduced lifecycle costs and more opportunities for off-site manufacture.

Section one of the SSLD guidance includes performance requirements for different types of partitions and
surface finishes.

 

Performance requirements


Partitions in secondary schools should meet the highest category of BS 5234-2, the British Standard for partitions. These are “severe duty” partitions for areas “intensively used by the public with little care, prone to vandalism and abnormally rough use”.

There are several areas to think about when specifying partitions in schools, including resilience, acoustics, moisture, insulation, fire resistance and sustainability.

• BS 5234-2 provides test methods and criteria for stiffness; the impact of small hard bodies, large soft bodies, door-slamming and crowd pressure; fixing methods Partitions are expected to have a service life of about 60 years

• Partitions are vital to a building’s acoustics, as they provide insulation from airborne, flanking and impact sounds, and control reverberation and absorption.

• Advice on this can be found in Building Bulletin 93 on the specification of acoustic performance

• There may be hygrothermal variation within a building, so partitions should be able to withstand normal, humid or wet conditions, as required. Extra precautions are required at the base of partitions in wet areas or where wet floor washing is anticipated

• Where partitions form a boundary to an unheated part of the school, additional insulation may be required to ensure a minimum U-value of 0.35W/m2K

• Partitions should be designed to resist fire for 120 minutes. The spread of flames across a surface is related to the finish, and the requirements for this varies. For general areas BS EN 13501: class C-s3, d2 (UK Class 1) applies and for escape routes BS EN 13501: class B-s3, d2 (UK Class 0). Information on how glass, ductwork and services are related to the building’s fire safety strategy are included in Building Bulletin 100, on designing for fire safety in schools

• Ideally, all partitions will achieve an A rating in the BRE’s Green Guide to Specification (an updated edition of this is due later in 2008).

 

Specification options


SSLD 1 gives three partition wall types: A masonry system based on lightweight, solid concrete blockwork and two metal stud partition systems.

Lightweight blockwork is made of solid concrete blocks with a minimum strength of 7N/mm2. Finishes may be directly applied or lining included for better acoustic insulation.

Metal studs and ancillary components are typically manufactured from low-carbon steel, with a galvanized zinc finish.

Insulation between studs can be mineral wool, modified sheep wool or recycled plastics fibre.
Wall lining options include plasterboard, gypsum fibreboard, glass fibre-reinforced cement panels, calcium silicate board or cement-bonded particle boards.

Surface finishes include paint, epoxy coatings, plastic laminates or ceramic tiling to suit the performance requirements.

 

 

Specification options

 

Internal non-loadbearing partitions in schools
Suitable for classrooms and circulation during lesson times.
Partition wall type B to SSLD 1
Capital cost £/m2 Net present value for 60 years £/m2
Lightweight solid concrete block    
140mm thick, 1450kg/m², 7N/mm²; Suitable for plaster finish; 13mm, 2 coat plaster on both sides. 64 131
Fair faced, 140mm thick, 1450kg/m², 7N/mm²; Good workmanship. 47 111
Gypsum fibreboard on 75mm steel studs with 60mm 35kg/m³ insulation    
One layer of 12.5mm gypsum fibreboard on each side of the partition joints taped and filled screws stopped; Fine surface finish. 77 140
Plasterboard on 70mm steel studs with 50mm 12.9kg/m³ insulation    
Two layers of plasterboard on each side of the partition: outer 13mm high density impact resistant board and 15mm inner sound absorbing board; joint filler tape, joint finish and filling. 94 161

 

Table notes


A discount rate of 3.0% is used to calculate net present values.

Life cycle costs include capital costs for the internal partitions with emulsion paint finish, component replacement, inspection, cleaning, redecoration and an allowance for minor repairs related to risk. Costs are indicative averages. Steel studs at 600mm centres. No allowance for economies of scale.

Expected service life for each option is 60 years. Differences in life cycle cost is related to the surface finish and the risk of damage to the finish and partition.

A cost analysis based on project specific information is essential for a realistic best value appraisal. For schools each room and adjacent area should be assessed to determine the partition requirements.

SSLD 1 gives discounted cost examples for 30 year concession.

 

Further information


BLP provides latent defect warranties for buildings www.blpinsurance.com

Further information contact peter.mayer@blpinsurance.com or telephone: 020 7204 2450

 

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