CharlotteJ

Thanks so much for all the info, particularly the picture, very interesting and informative. We're going to try and insulate as best as possible as have two elderly relatives living with us who have their TV very loud!

Hi, having read through loads of posts about sound insulation, I am still confused! Our builders merchants have recommended Isover APR1200 75mm for our 100mm studs. Density is 12kg/m3. Cost approx £4.09 per m2 From this forum, Rockwool RWA45 75mm is recommended often, Density 45kg/m3. Cost approx £6.19 per m2. Ive read conflicting views on higher density being better. We are thinking of boarding each side with blue plasterboard - does this make much difference, or would two standard plasterboard with staggered joints be as good - less heavy to deal with! Any other product recommendations or advice/experiences please?

We've been recommended Sikacryl®-620 Fire to seal the joints where the plasterboard meet and along edge where board meets concrete floor or block wall. Wood wall plate is covered with pink board and extended each side. We've pink board directly beneath the felt, which meets the top of the fire wall and again, joints sealed. I will check the plan for the soffit. Thanks so much

Sorry, meant to quote your reply...... Thanks for your reply. The sole plate is being fixed to existing concrete floor so I didn't think we would need to put pink/fireboard under it? We are boarding tight to the concrete floor (on DPC) then use the fire rated mastic where the board meets the floor - same with where the stud is against the block wall - we will board tight up to the wall and then fire rated mastic between the edge of the board and the block wall. Is this acceptable in your opinion? Thanks

Thanks for your reply. The sole plate is being fixed to existing concrete floor so I didn't think we would need to put pink/fireboard under it? We are boarding tight to the concrete floor (on DPC) then use the fire rated mastic where the board meets the floor - same with where the stud is against the block wall - we will board tight up to the wall and then fire rated mastic between the edge of the board and the block wall. Is this acceptable in your opinion? Thanks

Hi, our structural fire wall between two dwelling (single storey) will be pink boarded both sides and continues up into the roof space, to underneath the roofing felt. Is it acceptable to cover the head of the firewall (where it would meet the roofing felt) with pink fireboard also, we will fill any joins between head of wall plasterboard and wall plasterboard with appropriate fire rated sealant. Or must I use a specific product for this? There will be additional firestop between battons and roof tiles as required. Thanks for any help given.

I dont believe it is class Q. It was an agricultural building although a modern building rather than stone barn. We have full PP for change of use to two dwellings - its a large C shaped building so a two bed and a 7 bed separated by an internal fire wall. Thanks, I will have a search on youtube.

Hi, we are converting a concrete block building that was originally built around 2007. It has 7n concrete blocks (100mm thick) external walls apart from gable ends and the long rear wall which are all 7n concrete blocks on the flat side (215mm) thick. There is a DPC strip under all the blocks at floor level. We have established that we need to build the floor up in order to insulate and achieve required U values. We are now looking at the walls and I want to check cavity requirements. I have seen conversion videos where there is no cavity and studwork is covered with a membrane and installed up against the block walls then insulated. - Not sure how to calculate the U value of this method. The Kingspan U value calculator option is 50mm cavity, studwork backed with OSB and membrane, insulation inside studs, then insulated plasterboard - to achieve required U values. This is difficult to retrofit as I think it would need tying in? Also would we need a cavity tray? - we could achieve this as there is enough DPC protruding from the bottom of the walls to wrap across the 100mm high sole plate, to create the slope and install weepholes. Two very different methods - any advice much appreciated! Thanks

Thanks everyone. Would stud wall with insulation, ply both sides (this makes it structural according to BC) then boarded each side be suitable? - I could then find out the stud wall thickness and what insulation and plasterboard to use in order to meet the soundproofing requirements.

Thanks so much for all your advice. On talking with BC today, the firewall also needs to be 'structural' although not load bearing (single level building). So a 100mm solid concrete block wall is suggested as being appropriate for fire rating - 60 mins required - I need to check if it will give adequate sound insulation but would appreciate your advice and any opinions on this.

Thank you, I will check out the guides that you mentioned.

Hi, we are converting a large building into 2 dwellings - we need an internal firewall to separate them. From various builders advice and the internet, we are thinking a stud wall using 6"x 2" timber, filled with either rockwool or rigid celatex type insulation and boarded both sides with pink plasterboard, then skimmed. This will continue up into the roof space. This will all be approved by our very helpful building inspector before installation, but I would like to have something to show her. Any comments, advice or additional information is very welcome. Thank you.

Yes it was previously an agricultural building so exempt. Thanks for your help.

Thank you. That's really good to know

Joe90 - I was hoping he would advise what he required. I will arrange for him to come out for a site visit. Thanks so much for your reply.