Sound Insulation Assessment Report

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Sound Insulation Assessment and Design

Quines Corner 1 Quines Corner North Quay Douglas Isle of Man

Date of Report: Tuesday 29th April 2014 Reference: 6385

RECEIVED ON 08 MAY 2014 DEPARTMENT OF INFRASTRUCTURE

This report may not be reproduced other than in full, except with the prior written approval of Soundtesting.co.uk Ltd

North Office 44 Canal Street Bootle Liverpool L20 8QU t 0151 933 6186 f 0151 922 7742 e [email protected]

South Office No. 6 Tuscan Studios 14 Muswell Hill Road Highgate London N6 5UG t 020 3286 2019 e [email protected]

Presented Cen 14/00/463 Received 8.5.14

DEPARTMENT OF INFRASTRUCTURE PLANNING and BUILDING CONTROL DIVISION Town and Country Planning Act 1999 Date and Officer Initials

1.0 General Information

1.1 Site Address

1 Quines Corner North Quay Douglas Isle of Man

1.2 Client Instructing Survey

Heron & Brearley Ltd Old Castleton Road Kewaigue Isle of Man IM2 1QG

1.3 Consultant

	Name	Position	Signature	Date
Prepared by	M S Hamer AMIOA	Acoustic Consultant	M. M.	29/04/14
For and on behalf of: Sound Testing.Co.Uk Ltd

1.5 Report Approval

	Name	Position	Signature	Date
Report Approval	M J M Howell MIOA	Acoustic Consultant	M. M.	02/05/14
For and on behalf of: Sound Testing.Co.Uk Ltd

2.0 Introduction

This report follows report 6243; a Desk Top Sound Insulation Feasibility Report written 04 March 2014.

The above address is an existing building, which is attached to The Bridge Public House. The ground floor is to become vacant and it’s proposed to convert the unit into a restaurant. The first floor is a residential dwelling.

The floor between the proposed restaurant and residential dwelling is believed to be 200mm concrete.

It is believed that no structural changes to exterior or internal walls are proposed.

2.1 Sound Insulation Assessment and Design

Soundtesting.co.uk Ltd has carried out a site investigation and sound insulation test in order to establish the acoustic performance of the existing separating partition between the proposed restaurant and residential dwelling.

The report will provide guidance of the sound insulation of the concrete partition and compare the results with NR curves applicable to residential dwellings.

4.0 Criteria

4.1 NR Curves

NR curves are a series of curves, each curve having a defined value at each octave band. The curve is named after the 1KHz value.

Noise rating curve	Application
NR 25	Concert halls, broadcasting and recording studios, churches
NR 30	Private dwellings, hospitals, theatres, cinemas, conference rooms
NR 35	Libraries, museums, court rooms, schools, hospitals operating theatres and wards, flats, hotels, executive offices
NR 40	Halls, corridors, cloakrooms, restaurants, night clubs, offices, shops
NR 45	Department stores, supermarkets, canteens, general offices
NR 50	Typing pools, offices with business machines
NR 60	Light engineering works
NR 70	Foundries, heavy engineering works

*The values for a typical busy restaurant are taken from The Little Red Book of Acoustics. These values give typical spectral dB levels for common noise sources and events; these provide a general overview of the orders of level which would be expected.

The measured levels are below the recommended NR curves and therefore meet both NR 30 and NR25.

	Octave Band Centre Frequency (Hz)
63	125	250	500	1K	2K	4K
Typical Busy Restaurant $L_{\text{eq}}$*	60	70	75	75	75	75	70
Standardised Level Difference Dn,T values from site test	37.4	40.6	41.7	49.1	58.6	67.4	72.3
Predicted Levels	22.6	29.4	33.3	25.9	16.4	7.6	-2.3
NR30	59.2	48.1	39.9	34.0	30.0	26.9	24.7

As a precautionary enhancement it is recommended to construct and independent ceiling below the concrete slab. This should consist of a MF Ceiling on acoustic hangers. Two layers of 12.5mm plasterboard should be fixed to the underside of the metal frame and sealed around the edges with 100mm mineral wool; density 45kg/m³ such as Hush Slab or similar fitted above the plasterboard.

The new ceiling should be continuous and free of any penetrations or ventilation systems. If inset lights are intended to be used; acoustic hoods should be fitted over the light fittings.

The restaurant should have sound absorbing material installed in the interior to control reverberation and sound reflections on hard surfaces. This could be achieved by installing sound absorbing panels. Please refer to www.restaurantnoise.co.uk.

9.0. Conclusions

The sound insulation test has demonstrated the current floor performance. This has been used to estimate the internal noise levels based on the values for a typical busy restaurant.

As a precaution further acoustic treatment is recommended to the construction in the form of a MF Ceiling system.

Reverberation should be kept to a minimum by installing sound absorbing panels.

10.0. References

The Little Red Book of Acoustics – R. Watson & O Downey Acoustics and Noise Control 3rd Edn – Peters, Smith and Hollins www.google.co.uk/maps www.restaurantnoise.co.uk