Approved Document E Technical Design Report

Transcription

1 Approved Document E Technical Design Report Report No Date 15 th April 2013 Sound Solution Consultants Ltd. Ref Page 1

2 Client: Site Address Brighton Our Report Ref:15692 Table of Contents 1. Overview Page 4 2. Our Brief Page 5 3. Approved Document E Requirements..Page 5 4. Current status... Page 6 5. External Wall Construction Page 7 6. Party Floor Between All Levels Page 9 7. Party Walls.. Page Internal Stud Walls. Page Internal Compartment Floor... Page Additional Flanking Routes.... Page Bathroom Fitting Details. Page Treatment of Stairs.Page Final check.. Page 19 Sound Solution Consultants Ltd. Ref Page 2

3 STATUS SIGNATURE / NAME / POSITION DATE ORIGINATED Mark Page MIOA - Managing Director 15 th April 2013 CHECKED Steve Skingle BSc. (Hons) MAES AMIOA Senior Acoustic Consultant 15 th April 2013 PASSED Mark Page MIOA - Managing Director DOC REF th April 2013 Sound Solution Consultants Ltd. Ref Page 3

4 1. Overview 1.1 I understand this is a New Build Development of 23 Flats, split over four levels in 2 separate blocks namely A + B, the project is being built under Pre-completion Testing procedures within Approved Document E. 1.2 There is also a requirement from the client to achieve Code 3 of sustainable homes, which basically means they need to achieve 5dB above basic building Regulations. 1.3 Entrance to the Flats, is via entrances on the Ground floor of each block. A lift is located towards the centre of the building, with in general, 2 flats per level 1.4 The Building is of Cavity Brick and Block, at Ground floor level changing to light weight metal construction from 1 st floor and above. 1.5 The client has asked us to review the drawings and recommend treatments as required. Please see General Arrangement below. Fig 1 Party Walls Requiring Treatment Party Floors Requiring Treatment 9 Flats and a ground floor carpark. This is a very simplified representation of the layout, it is not to scale and should only be used for reference purposes. Sound Solution Consultants Ltd. Ref Page 4

5 2. Our Brief 2.1 We have been instructed by the client, to provide acoustic design advice such that compliance with Approved Document E can be achieved, including the specification of suitable products to achieve the compliance as cheaply as possible. 2.2 Additionally the client is aiming for Code 3 of the sustainable Homes Scheme and as such requires specific guidance to try and achieve this. The credits available under the scheme are listed below; Where: Credits airborne sound attenuation values are at least 3dB higher 1 impact sound attenuation values are at least 3dB lower OR airborne sound attenuation values are at least 5dB higher 3 impact sound attenuation values are at least 5dB lower OR airborne sound attenuation values are at least 8dB higher 4 impact sound attenuation values are at least 8dB lower than the performance standards set out in the Building Regulations 3 Approved Document E Requirements 3.1 In a strict assessment of the situation the project falls with in the New Build scope of Approved Document E of the Building Regs and as such should meet the standard criterion as detailed below. 3.2 New Build Purpose Built Flats Separating Floors Under Approved document E, you are required to carry out sound tests on all separating floor constructions, where there are rooms on both sides of the Separation point, we are not allowed to test into corridors or hallways for instance. Although only a percentage of constructions will be tested, all floors should be capable of meeting the standard set below: Basic Approved Document E Criterion. Code 3 Separating Floor Between Flats Airborne Noise Reduction = 45dB Dn T,w + (Ctr) or greater min 50dB Separating Floor Between Flats Impact Noise Reduction = 62dB Ln T,w or less max 57dB 3.3 A minimum of 1 set of Tests are required per method of treatment for every 10 Flats, as we are using 1 method of Floor treatment in this property, then the total number of tests required, will be as follows: 2 Airborne Floor Test to achieve 45dB Dn T,w + (Ctr) or more between any 2 floors 2 Impact Floor Test to achieve 62dB Ln T,w or less between any 2 floors 3.4 New Build Purpose Built Flats Separating Walls Sound Solution Consultants Ltd. Ref Page 5

6 Under Approved document E, you are required to carry out sound tests on all separating wall constructions, where there are rooms on both sides of the Separation point, we are not allowed to test into corridors or hallways for instance. Although only a percentage of constructions will be tested, all walls should be capable of meeting the standard set below: Basic Approved Document E Criterion. Code 3 Separating Wall Between Flats Airborne Noise Reduction = 45dB Dn T,w + (Ctr) or greater min 50dB 3.6 A minimum of 1 set of Tests are required per method of treatment for every 10 Flats, as the construction method will be identical then we will be required to carry out the following number of tests. 2 Airborne Wall Tests to achieve 45dB Dn T,w + (Ctr) or more between any flats 3.7 I would advise that you check the above testing schedule with Building Control, as any change from the above will have affect the overall costs of testing. Unless we are told otherwise we will test as described above. 4. Current Status 4.1 The building is currently still in the design stage. Sound Solution Consultants Ltd. Ref Page 6

7 5. External Walls 5.1 We understand that the external walls at Ground Floor level consist of a 100mm thick inner leaf 100mm typical void and normal brick outer skin. These inner leaf block walls then support concrete cast in situ floor slabs, concrete pillars then support further cast in situ floor slabs. 5.2 The external walls on the upper 3 levels are constructed from a light weight metal wall skin system. As the external walls at 1 st floor and above are intended to be Metal Stud Construction then these inner leaf blocks at ground floor level should have a min density of 1350kg/m3. I would then suggest that the inner face of external walls should be Rendered and plastered min 20mm thick. 5.2 Dot and Dabbing plasterboard onto block walls, can cause resonance in the plasterboard sheets, thereby increasing the likely hood of Flanking Issues, this should be avoided at all costs. 5.3 You should also ensure that: i) Ensure that these blocks are well mortared and pointed, do not allow gaps to be between blocks. ii) Ensure that the correct number and type of wall ties are used. iii) Ensure that you use a cavity closer in the cavity wall at each floor level Please see cross section diagram below. Sound Solution Consultants Ltd. Ref Page 7

8 Fig 2- External Wall to floor Junction Min Density 1350kg/m3 Sound Solution Consultants Ltd. Ref Page 8

9 6. Party Floors between all levels 6.1 The Party Floor construction comprises of 225mm cast in situ floor slab, this is supported by concrete columns. 6.2 The current design shows the inner leaf in a light weight metal stud system sitting onto the concrete slab. The outer skin is again a light weight lining system Fig As there is little historic data as to the realistic acoustic performance of this design, caution needs to be taken over this method of construction, especially when considering the extra performance required under Code For Sustainable Homes scheme. It can however be compared against a timber frame type construction albeit with a heavier floor system. 6.4 In using the principles of the timber frame as a guide, I would suggest that the inner lining configuration is beefed up as there is a risk of Flanking occurring down the inner leaf components 6.5 To this end I would recommend having a backing board of min 12mm cement based board onto the back of the inner leaf. However this backing board must NOT run through as currently shown in diagrams, or indeed can the external ling frame also run continuous as this will provide a route for sound to travel through. Please see suggested diagram below; 6.6 The floor construction is currently shown as 225mm cast in situ slab, with Screedboard 28 on top and a suspended ceiling of a single layer of plasterboard below with a 100mm void for services. Sound Solution Consultants Ltd. Ref Page 9

10 6.7 I would again suggest this is upgraded also, since this configuration is only likely to achieve Fig 4 Cross section detail 2 x 15mm SoundBlock fixed to Metal Stud Isolation perimeter strip Min 50mm Insulation 45kg/m3 28mm Acoustic Floor Cavity Fire Slab 100mm void 50mm 16kg/m3 Rockwool Mastic all gaps 2 layers of 15mm SoundBlock Plasterboard Acoustic Hangers for Metal Frame Ceiling 2 x 15mm SoundBlock fixed to metal stud Min 12mm Cement Board Sound Solution Consultants Ltd. Ref Page 10

11 Important points to consider a. Acoustic Hangers are not standard with M F Ceilings and need to be ordered specifically b. Ensure plasterboard sheets on ceiling are staggered c. Ensure plasterboard caps are placed on top of each inner leaf. d. Do not install recessed lights in this ceiling, use an additional sacrificial ceiling for recessed lights e. Seal all gaps between sheets of plasterboard and around ceiling edge prior to plastering f. Build all internal and Party Walls from sub floor up to underside of concrete slab g. Ensure all gaps are sealed with mastic or silicon. h. Ensure Metal Frame ceiling is installed to manufacturer s instructions based on loading (25kg/m2 approx.) i. Seal the bottom and top edge of all internal and party walls with mastic. j. Ensure all perimeter joints on wall and ceiling are sealed with silicon or mastic. k. Fit isolation tape around edge of each room prior to fitting acoustic flooring l. Screw and glue 28mm thick proprietary acoustic floor min mass 13kg/m2 m. Ensure any air handling units being fitted n ceiling void are resiliently mounted. n. Ensure all gaps are sealed Specific Materials 1. 50mm Thick insulation min density 16kg/m mm SoundBloc Plasterboard 2.4m x 1.2m x 15mm 3. 28mm Acoustic Floor min mass 13kg/m2msujdlksndcn 4. Isolation Tape 75mm x 5mm x 50m Rolls 5. Joint Adhesive, 6. Acoustic Sealant 7. MF Ceiling system 8. Acoustic Hangers mm Insulation slab min 45kg/m3 (internal partitions and inner skin of external wall) Sound Solution Consultants Ltd. Ref Page 11

12 7 Party Walls 7.1 Under Approved Document E, you are required to insulate against Airborne noise in all walls that separate any part of a flat with another flat or communal area, in practice however we would only test between habitable rooms ie Bedroom to bedroom or living room to living room. 7.2 The client is forming Party Walls on all Floors in this development, in some cases they will separate rooms of different flats whilst in other areas they will separate flats from communal areas. The construction method will be the same throughout the build. 7.3 In all cases the same Party Wall construction will be suggested, again of course we are aiming for +5dB over Building Regulations standard, normally I would therefore suggest that the following British Gysum construction should be adequate to achieve the required 50dB, providing the detailing is followed carefully. New Party Walls Current design new party walls is based (to be confirmed see above) on Gypwall QUIET IWL formed with Two 60mm Gypframe I Stud frameworks. Studs at 600mm centres. 100mm Isover APR 1200 in the cavity. Linings to be SoundBloc 2 x 15mm to both sides, skim finished. Overall thickness 250mm. Additional strengthening to be provided at door openings to take weight of doors, with timber battens fixed to C channel Fig 5 Fig 6 British Gypsum Ref A Timber Equivalent 7.5 Alternatively you could use a standard Timber Stud Configuration comprising 2 x 100mm x 50mm studs set 50mm apart, one inner face lined with 12mm PLY sealed edges. 50mm insulation fitted inside each stud, and both outer faces lined with 2 x 15mmSoundBlock Plasterboard. 7.6 All Party Walls need to be built up to the underside of the subfloor from the base floor, with all gaps sealed. Please see Detail below based on same separating floor structure as detailed above. Sound Solution Consultants Ltd. Ref Page 12

13 Fig 7 Party Wall / Floor Detail Cross section detail Isolation perimeter strip 28mm Acoustic Floor Floor Slab 100mm void 2 layers of 15mm SoundBlock Plasterboard 50mm 16kg/m3 Rockwool Sound Solution Consultants Ltd. Ref Page 13

14 8. Internal Stud Work 8.1 There is no requirement here except for the standard Rw 40 db Wall that would normally consist of a 4 x 2 stud and a single layer of plasterboard both sides and with 50mm 10Kg/m3 Insulation. 8.2 Internal hallway walls within each dwelling are technically excluded from this Rw 40dB requirement, however it is normally recommended to keep the same specification throughout as it helps to keep a reasonable acoustic performance in all areas of the flats as well as reducing the chances of under insulation of room to room partition walls. Fig 8 100mm x 50mm metal Stud Bedroom Bedroom Single layer of standard plasterboard both sides of metal stud. 50mm thick Insulation slab, min density 16kg/m3 8.3 All internal stud work can be built onto the Concrete slab. 8.4 It is important to ensure that the plasterboard is taken and sealed down to the base floor construction to prevent gaps under the bottom of the plasterboard sheets. 8.5 Internal walls are not tested at any stage. 9. Internal Compartment Floors 9.1 Where A flat is split over 2 levels, such as with flats 1 and 2, there is no requirement here except for the standard Rw 40 db. This can be achieved with a standard ceiling of single 12.5 plasterboard on a metal frame ceiling, there is no direct need for an acoustic floating floor however you may need it to keep floor levels above the same, in any case it will help protect against Impact Noise issues if you are thinking about Hard floor finishes. If carpet and underlay then you can omitt the acoustic floor. Sound Solution Consultants Ltd. Ref Page 14

15 10. Additional Flanking routes ie Steel Beams etc 10.1 In conversions such as these, there are always other routes that the sound will try to take during the test, these are called Flanking Routes, please see below for Flanking routes that have been identified: a. Service pipes work running through Party Floor b. Steel beams and columns c. Supporting Steel I Beams d. Lift Shaft e. Electric Sockets in Separating walls 10.1a. Service pipe work runs I understand that some services will be taken through the floor, you will therefore need to treat these as shown below. Fig 9- Plan view of Soil Pipes Timber box frame 2 Layers of plasterboard Insulation packed around pipe work sub floor Isolation Tape Please Note These pipes should pass through small holes in the floor and ceiling, please avoid cutting large service voids through a floor construction as these allow lots of sound through. If soil pipes pass horizontally under the new ceiling, these should also be boxed in to reduce sound breaking out of the area, I would again suggest boxing in with an independent timber frame and Sound Solution Consultants Ltd. Ref Page 15

16 packing the pipe with insulation before double boarding around the frame work, please see cross section detail below. Fig 10 Steel Floor beam Soil Pipe Insulation 10.1b. Steel Beams If there are steel beams in places within this development, in general you should ensure that: i) Do not run Steel Beams between flats so that they are continuous through a Party Wall. ii) Always ensure that the steel beam is concealed by at least 2 layers of 15mm sound block plasterboard to protect against the steel resonating iii) Ensure that the steel beams are packed with dense Rockwool insulation prior to being concealed. iv) If Steel I beams protrude within the ceiling void then you should ensure that insulation is fixed below the steel and you have a clear 50mm void below insulation. There must always a min 2 layers of 15mm Sound Block plasterboard between any steel visible and the room. DO NOT CONNECT CEILING DIRECTLY TO STEEL I BEAM. Sound Solution Consultants Ltd. Ref Page 16

17 10.1 d. Lift Shaft Where the Lift Shaft is located you ought to use a cavity wall construction, however if not the space then a single 200mm dense block laid flat, min density 1850kg/m3, this is to try and stop vibrations being passed into the building structure d. Electric Sockets in Separating walls Under Approved Document E guidelines you are advised not to put sockets BACK TO BACK in both sides of a Party Wall, as sound will try to break through at these points. Please offset by min 1m. 11. Bathroom Fittings 11.1 When installing sinks and toilets or indeed shower trays into rooms where acoustic floors are being installed then the flooring is the last thing to be added, you must never fit toilets etc onto floating floors as the movement that will naturally occur may damage tiles or joints Instead you should create a plinth for each item, the thickness of the floating floor and fix it directly to the original floor surface, you can then place the flooring up against these plinths using the Isolation tape as a seal. Please see fig 11 below. Plinth Toilet or sink Flanking Tape Acoustic Flooring Insulated Soil Pipe passing down through floor construction If fitting Tiles then you can replace acoustic flooring with a 5mm Resilient Layer such as Regupol 4.5mm Multi over Laid with Ditra Mat and then tiles. Sound Solution Consultants Ltd. Ref Page 17

18 12. Treatment of Stairs 12.1 Where a communal staircase is located directly above another Flat, then this should also be treated, however it will not require testing. You do not need to do this where the stairs is always in a communal area Where the stairs is concrete, I would suggest that you use a soft floor covering on landings and stairs as this will help reduce sound created in common areas Reverberation Treatment- Within Approved Document E you are required to control internal reverberation within communal corridors 12.4 I can confirm that you will need some additional absorption within the communal areas / lobbies, this will need to come in the form of ceiling absorption, you will need a class C Absorber over all horizontal areas of the communal area ceiling at all levels Most manufacturers will be able to provide such a product but if you need assistance in sourcing such a product then please call me. Typical manufacturers would be JC Wilkins and Hodgson and Hodgson. Choosing textured wall and ceiling finishes would further improve the situation. The architect has already suggested some suitable products Armstrong Ceilings Dune Max and Ultima or Perforated plasterboard like British Gypsum Gyptone QUATTRO 20, Sound Solution Consultants Ltd. Ref Page 18

19 13.Final Comments 13.1 Since the aim here is to achieve additional performance such that 3 Credits can be achieved under Code for Sustainable Homes, it is vital that construction details are followed carefully, we can not be on site at all times and therefore it will be down to the site manager to ensure the details shown above in this report are followed We are of course still expecting to visit site at convenient points so that we can check for any other issues that may arise not apparent in the drawings, to this end we ask that we are kept informed about the status of the project so that we can arrange visits at suitable times e are any problems caused by the treatment details provided, please feel free to call and discuss further Since this construction method is not a common method of construction, there is little in the way of supporting acoustic data for such systems, we have therefore had to draw on our experiences of other similar projects, although to date we have not come across this exact configuration. I trust the above is acceptable but if you have any questions regarding the above then please call me on the numbers above, I look forward to hearing from you in regard to supply of the materials suggested and I remain I trust the above is acceptable but if you have any questions regarding the above then please call me on the numbers above, I look forward to hearing from you in regard to supply of the materials suggested and further site visit as discussed, I remain Yours sincerely Mark Page M.I.O.A. (Member of the Institute Of Acoustics) Please note, the success of any acoustic system, will depend entirely on the construction of the existing building and finishing detail, to the extent that we can not guarantee the level of noise reduction that will actually be achieved. VAT No Reg No Registered Address 57 Thorney Road, Capel St Mary, Ipswich IP9 2XH Web site: Sound Solution Consultants Ltd. Ref Page 19