Acoustic Underlay for Airborne Noise Reduction

There is a common misconception concerning acoustic underlays and what is required of them. Most people want an acoustic underlay to reduce airborne noise such as speech and music being heard through a floor. So when they go to buy a new carpet, they also ask for a sound absorbing underlay from the carpet supplier. The carpet supplier will then usually offer an underlay that has been acoustically tested and has a test result of say, 34dB that sounds fantastic. But what the supplier and customer do not realise is that some underlays sourced from carpet suppliers have only been tested for impact noise reduction and the 34dB does not mean it will reduce noise through a floor by that amount. What it really means is that it will only reduce impact noise such as footfalls and the lower the test figure, the more efficient the product is at reducing that type of noise. Usually it will have no effect at all at reducing the airborne noise which is what the customer is really looking for. To do that, heavy materials have to be installed. Lead for instance, due to its high mass is an excellent sound blocking material but obviously impractical and far too expensive to fit onto a floor. Instead, an acoustic underlay specially designed using mineral loaded sound barrier mat and sound absorbing foam with the foam sandwiched between two layers of the barrier mat will give the best results. This product is used in place of the normal underlays talked about earlier and no additional underlay is required. The product to look for is QuietFloor Plus which is marginally thicker than the best underlays at 15mm thick. Because this product is heavy, it cannot be supplied in the usual rolls but in easy to handle panels 1200 x 600mm. QuietFloor Plus will improve the sound insulation of most floors by an average of 5dB which is more than 50% of the original noise nuisance. It is easy to install and is supplied with full installation instructions. There is nothing better than QuietFloor Plus for use as an acoustic underlay that will reduce both impact noise and the more important airborne noise and can be so easily installed. For more information on this product go to the product page on the domestic web site of Sound Service (Oxford) Ltd. via this link QuietFloor Plus or alternatively, give Sound Service a call on 01993 704981

Soundproof a Floor Question and Answer

Soundproofing a floor to Part E Standard #3

A previous Blog was an introduction to floor soundproofing and mainly talked about flanking noise and how to deal with it. That Blog also referred to upgrading the soundproofing of a separating floor in flats to comply with the Building Regulations for the control of noise through floors. These regulations are contained within a document called Part E Resistance to the Passage of Sound. For a lot of new build and change of use when a building has been converted into flats, the floors have to be tested to prove compliance. But in the case of upgrading an existing separating floor no testing is required. This is because there is no legal obligation to bring an existing floor within a flat to comply with current regulations for noise control. Having said that there are still many flat owners that would like to upgrade their floors and if they have the co-operation of their neighbour beneath, then it should be possible to upgrade to a good level of soundproofing.

First off, if there is a lathe and plaster ceiling attached to the ceiling below whatever you do not remove it! Lathe and plaster ceilings are better than the plasterboard replacements often used instead. What should be done is simply screw up another layer of 15mm high density Acoustic Plasterboard that will add mass and secure the plaster from detaching from the lathes as sometimes happens when it has been up there for a long time.

If it is simply a plasterboard ceiling then this can be removed and replaced with 30mm (2 x 15mm) of Acoustic Plasterboard decoupled from the underside of the joists with 15mm deep Resilient Bars. Inset ceiling lights should be avoided because these will let noise through just as easily as leaving a hole in the ceiling. All lighting should be surface mounted with holes for wiring sealed with Acoustic Sealant. More information our Resilient Bar system including installation instructions can be viewed on our web site. This work on the ceiling is all that is required from below. The rest of the soundproofing can now be installed from above. For flat owners that do not have the co-operation of neighbours above, carrying out the work just described will reduce noise through the floor from above and if you can also install 100mm of Acoustic Mineral Wool (AMW100) as a loose fit to sit on top of the Resilient Bars, it will be difficult to improve on the soundproofing carried out from below.

Now we can go to the work that can be carried out from above and the same applies here. If you do not have the co-operation of the neighbour beneath, the following soundproofing work will be the best you can achieve and certainly worthwhile.

First of all remove the skirting boards and lift the floorboards to expose the joists beneath then insert as a loose fit 100mm of AMW100 Acoustic Mineral Wool that is a Rockwool type product but produced to s specific density to give maximum sound absorption. Now if the floorboards are in good condition, refit them with screws strategically placed so the boards don’t squeak when walked on. Ensure that any gaps around the perimeter of the floor are sealed with Acoustic Sealant. If the floorboards are not fit for re-use, replace them with 18mm QuietBoard, a high density tongued and grooved acoustic floorboard. Once the floor is laid and sealed, overlay with 2mm of SBM5 Soundproofing Mat loose laid wall to wall with the joints tight together. Once that s down then overlay with 10mm of R10, a recycled rubber resilient insulation for supporting a floating floor. This has to be laid across the entire floor with the joints tightly butted. Once this is down, a floating floor of QuietBoard can be laid on top but this time with a 5mm gap around the edges that can be sealed with Acoustic Sealant. All that now remains is to refit the skirting boards so as to be just clear of the floating floor. About 1mm is sufficient and this gap does not require sealing.

That’s it. Job done and now you can get on with fitting the floor covering and for best results, make it carpet on top of a felt underlay.

All of the above soundproofing can be carried out as a DIY exercise by anyone used to handling small tools and full installation instructions to soundproof a floor can be viewed on our web site www.keepitquiet.co.uk

Domestic Pump Noise and Soundproofing Solution

Domestic water pumps for supplying showers and taps are extremely noisy and very disturbing when being used at night. Too many people do not take this into account when having one fitted and often have them fitted in cupboards or beneath baths where space is limited. It is only after installation that they become aware of the noise problem these pumps give off but the pumps are so badly sited it is impossible to install an effective soundproofing solution to reduce the noise. Most of these pumps are small so it is tempting to fit them into tight spaces where they will be unobtrusive but don’t do it because it will be a mistake.

Instead when considering the purchase of one of these pumps, also think about where it should be sited so that it can be acoustically treated to reduce much of the noise the pump would otherwise give off. The best place is in a cellar if there is one or alternatively the utility room, the loft or anywhere else where there is plenty of space.

Now for the best way to limit the amount of sound that the pump will emit. For best results the pump should be sited in an area where it can be enclosed in a box that will be large enough not to allow too much heat build up. It is not usually necessary to allow for ventilation because these pumps usually only run for short periods of time. Once the site has been established prepare a resilient base for it as follows.

Cut to size a 10mm AV (anti-vibration) mat cut to the dimensions that the inside of the box will cover and glue it to the floor. If the site is in a loft screw down a 25mm thick MDF panel onto the joists and make it large enough to support all the sides of the box. If the loft is already boarded the additional MDF board will not be necessary. Once the AV mat is glued down, glue on top of it a concrete patio slab available for a few pounds from your nearest DIY superstore, garden centre or concrete slab producer if you have one in your area. Now glue another 10mm layer of AV mat on top of the slab followed by a ply or MDF board thick enough to take the screws the pump will be screwed on with. The enclosure should be made using 18mm MDF and lined on the inside walls and top with 32mm sound insulation remembering to make the box large enough so as not to allow too much heat build-up.

Holes will have to be cut into the box to allow the pipes access to the pump and these should be about 6mm larger than the diameter of the pipes. The pipes themselves should be flexibly fitted to the pump and not rigidly and the holes in the box sealed with flexible Acoustic Sealant. If necessary, the box can be assembled with screws so that it can be taken apart easily should the pump require any future attention.

The soundproofing products that we can supply are as follows.

AV Mat 1m x 1m x 10mm

B6 Sound Insulation 1200 x 900 x 32mm

Acoustic Sealant in 380ml cartridges

Aerosol Contact Adhesive

More information on these can be viewed on the Domestic side of our web site www.keepitquiet.co.uk or go directly to our web page on how to soundproof a pump via this link https://www.keepitquiet.co.uk/pump_noise.html

More on noise through a party wall and flanking noise

As I have mentioned before, noise though party walls takes different forms and those which are loud are anti-social noise that can only be addressed by outside authorities. From now on we will talk about normal levels of noise such as talking that should not be heard during the daytime. Assuming it is normal levels of noise that have to be addressed we have to also think about flanking noise. Now flanking noise is noise that skirts around the party wall via the hollow sections beneath floorboards and also above the ceiling. With pre-war buildings these are usually the only areas that can be treated to reduce flanking noise transmission because there are no cavities in the structural walls that would otherwise allow the free transmission of noise. Chimney breasts and internal attached walls are other areas that can allow flanking noise but are usually impractical to effectively soundproof.

Firstly we will deal with pre-war houses and flats that usually have solid structural walls that do not require additional treatment. This means the floor and ceiling and these should be treated before doing anything with the party wall to reduce flanking noise in those areas. With the floor it will be necessary to lift the floorboards closest to the party wall and insert between the joists immediately adjacent to the wall Acoustic Mineral Wool. If the joists are supported by the party wall then install enough to cover 1200mm from the wall and along the space between the joists. If, on the other hand, the joists are parallel to the wall, then simply insert the acoustic mineral wool in the space between the first two set of joists then replace the floorboards and screw them down. Once refitted, overlay with 2mm of SBM5 soundproofing mat that will seal up the joints of the floorboards.

The same infill treatment using acoustic mineral wool should be carried out on the ceiling but if it is a top floor bedroom ceiling there may already be thermal insulation in between the joists and it is not wise to remove it. The ceiling itself can be upgraded with an additional layer of 15mm high density acoustic plasterboard that will add mass and therefore improve the sound blocking performance of the ceiling. Now the floor and ceiling have been acoustically treated we can look at what can be done to soundproof the party wall and I will cover this in my next article. In the meantime if you require any further information on how to soundproof a party wall go to our web page via this link soundproof a party wall.

This article is just an introduction to flanking noise that can skirt round party walls. More about how to soundproof a party wall will be published in the near future. If you want to see more about how we can help soundproof a home go to our web site via this link. Soundproof a home.

Noise in the New Year

Now that we are in the New Year and the festivities of Christmas is behind us you may be affected by additional noise from your neighbours or children playing their new sound system or computer games at higher volumes. Or some other means of generating more noise than before from newly acquired equipment. Well you do not have to put up with it but take measures to reduce the noise nuisance by installing strategically placed soundproofing measures onto your floor, wall or ceiling to insulate the noise coming through from the other side. We at Sound Service (Oxford) Ltd. have been specialists in the soundproofing business since 1969 so know a thing or two about the subject and are always happy to give free advice via telephone or email on any noise issue you may have. This will include advice on the best method of soundproofing to adopt according to your budget because spending more will not always get you the best. For instance, to obtain the best soundproofing of a party wall you would install an independent sound insulated stud wall and this is one of the cheapest methods of noise control through a party wall. In fact any stud system of noise control is usually cheaper and more efficient than alternatives, but of course, take up more space. So if space is an issue we can offer alternative options starting from as thin as 27.5mm (just over 1 inch). However, it is generally considered that more space has to be lost to get the best soundproofing results.

Noise through floors is usually an issue with older flats that were constructed prior to when consideration for sound insulation had to be built in. Although having said that, some newly built properties built using an approved Robust Detail standard still have noise problems because they were not built properly or the wrong materials used. But that is a different issue I will deal with at another time.

Back to soundproofing a floor. If you live in a flat again the best solution entails an increase in the floor height and the greater the increase, the better the sound loss. For best results a separating floor should be treated from the ceiling below, between the joists and the floor above but for this article we will assume you do not have access to the ceiling below and do not wish to lift the floorboards to install Acoustic Mineral Wool between the joists. So we will just deal with what can be done with the minimum of work which just means removing existing floor coverings. Once that is done you have the choice of simply installing an acoustic underlay instead of normal underlay beneath your carpets, laminate or wood floor or, if you can live with the additional height, install a properly soundproofed floating floor system that will raise the existing floor height by up to 30mm. And for belt and braces, install acoustic underlay on top.

To soundproof a ceiling is a different issue and depends on the type of ceiling already fitted and the level of soundproofing work you wish to undertake. The same principle of space applies as mentioned earlier and the more height you can lose the less noise you will hear from above (flanking noise aside which again, we will deal with in a later blog). We will start with the assumption that you just want to do something to reduce the noise from above with the minimum of disruption and accept the best results will not be achieved but some improvement will be attained and that is to screw up an additional layer of 15mm Acoustic Plasterboard with 1mm of SoundBlocker membrane sandwiched between the old ceiling and the new plasterboard. This is the thinnest solution and therefore, not the best unless the existing ceiling is lathe and plaster. It is never advisable to remove lathe and plaster ceilings because they are acoustically better than normal plasterboard ceilings. For better soundproofing and assuming you have an ordinary plasterboard ceiling this can be removed and replaced with a decoupled ceiling either using a Resilient Bar system or if space allows, a new, independent timber joisted ceiling suspended off wall mounted hangers. Whichever method is adopted, an Acoustic Mineral Wool infill should always be loosely inserted into the cavity before applying the 30mm of high density plasterboard.

More specific information on these methods of soundproofing a wall, floor or ceiling can be viewed on the domestic side of our web site www.soundservice.co.uk or you can call us on 01993704981.

Acoustic Mineral Wool

When upgrading the soundproofing of a stud wall or timber joisted floor, it is often felt by the uninformed that installing mineral wool will have the desired effect and magically soundproof the structure. The reality is that often, there is no discernible improvement in reducing the noise that you want to reduce. This is because the insertion of just mineral wool will only give an improvement of about 1dB. A better result would be achieved if the correct density Acoustic Mineral Wool (AMW) is used and installed as a loose fit and not tightly. This is because the AMW is a sound absorber not a sound barrier. On its own, AMW will give an improvement of up to 2dB which would still not be noticed on its own. It is designed to absorb the noise within the voids of stud walls and floors and will work best as part of an overall upgrade that would include the installation of sound blocking materials such as high density Acoustic Plasterboard for stud walls and ceilings, and high density floating floors which we will talk about in another Blog.

The thickness of installed AMW is also important. It is another myth that the more you put in the better the soundproofing will become but this also is not true. For timber joisted floors a maximum of 100mm (AMW100) is all that is required. Any more would be a waste of time and money and again for stud partitions, just the thickness of the stud is required up to 100mm.

When a greater improvement is required, the AMW can be replaced with our SoundBlocker Quilt which we will also talk about in another Blog. This Blog is designed to inform you that Acoustic Mineral Wool is an important part of any upgrade of the soundproofing of stud walls and timber joists but must be used along with other soundproofing materials properly installed to obtain the best results. For more information on our Acoustic Mineral Wool and other soundproofing products, go to our domestic web site www.keepitquiet.co.uk

SoundBlocker Membrane Soundproofing Mat

SoundBlocker Membrane has again been specified and supplied to upgrade the soundproofing of ceilings in flats with timber joisted ceilings in Birmingham. This is because the SoundBlocker soundproofing membrane has superb sound blocking qualities and is particularly effective when sandwiched between two layers of plasterboard. Because this soundproofing mat is not heavy, it is particularly the preferred choice for upgrading the soundproofing of any ceiling because it is not as heavy as our SBM5 or Tecsound sound barrier mats. At only 2kg per square metre it can easily be glued to a plasterboard panel before it is screwed to the ceiling sandwiching the soundproofing mat between the first and second layer of plasterboard. For best results the plasterboard used should be the high density acoustic plasterboard that is decoupled from the ceiling with our 15mm deep Resilient Bars or the more efficient GenieClip System. For more information on SoundBlocker Membrane go to our web page via this link https://www.keepitquiet.co.uk/acoustic_membrane.html and for information on all of our soundproofing products go to our domestic soundproofing web site www.keepitquiet.co.uk

Lathe and plaster ceilings, to remove or repair?

When lathe and plaster ceilings start to become unstable, they will shed pieces of plaster and the worrying thing is they could land on someone’s head causing injury so when this begins to happen, what is the answer? No it is not to wear a hard hat or replace the ceiling with plasterboard. Agreed plasterboard is a stable product and once up can be forgotten unless there is a flood above but plasterboard, even high density acoustic plasterboard, is not as acoustically efficient as lathe and plaster. So if you wish to reduce noise nuisance from above or if you want to avoid the dust and mess that removal of lathe and plaster ceilings entail, read on. Lathe and plaster ceilings and stud walls are usually constructed with thin timber lathes nailed to the underside of ceiling joists or frame of stud walls then rendered with a dense plaster that is skim coated and decorated to suit. This system creates a dense layer that is far more efficient at blocking noise than plasterboard even if a double thickness is installed and decoupled with resilient bars. What do we do instead I hear you ask? Well if the ceiling has started to shed plaster the first thing to do is effect a repair. If the ceiling is still sound then in both cases carry out the following which is simple, cheap and not nearly as messy. Screw a layer of 15mm Acoustic Plasterboard over the top of the existing ceiling/wall ensuring the screws fix into the joists or stud frame. Alternatively, if preferred, use a fireline board instead. Fireline boards are usually very dense as well and have the added advantage of being more fire resistant that plasterboard so if budget allows, use fireline board then skim and finish. If extra soundproofing is required, sandwich our SoundBlocker Membrane between the existing ceiling and the new board or if it is a wall, use our SBM5 soundproofing mat instead. For more information on soundproofing a ceiling or a wall.

Acoustic Doorseal Kits for Soundproofing a Door

Becoming more and more popular are our Acoustic Doorseal Kits designed to upgrade the soundproofing properties of lightweight domestic doors often found in the home. Bespoke Acoustic Doorsets are often too expensive for domestic use so the Acoustic Doorseal Kits are more affordable and can easily be fitted by and DIY orientated person. The kits comprise the normal triangular shaped “batwing” seals that when fitted to the doorframe, will seal the sides and top of a door and also a two part threshold seal for sealing the gap at the bottom of the door and it is this gap that usually lets the most noise through. In addition, the kit contains a sheet of SBM5 soundproofing mat and this can be glued or stapled to the door then covered with a sheet of ply or MDF to finish it off. The Acoustic Doorset Kits are very easy to fit and come complete with installation instructions, adhesive screws. The kits can be supplied to fit both single and double doors and once fitted, will improve the soundproofing properties of a typical lightweight domestic door from about 15dB to around 30dB. Alternatively, a heavy fire door could be used which is loads cheaper than a bespoke Acoustic Doorset and if fitted with one of our Acoustic Doorseal Kits will also give enhanced soundproofing performance. If a higher performing acoustic door is required then we can supply either a 35dB or 44dB rated doorset complete with frame and hinges. However, because these are made to order you have to allow around five weeks for delivery after receipt of any order and payment. For more information on our Acoustic Doors and Doorseal Kits or any other soundproofing products for the home, go to our domestic web site at www.keepitquiet.co.uk

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