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After reading every post on this forum on the subject of sound insulation and in particular Rockwool I wanted to document our experience. Until the delivery arrived and we opened the packets we really didn't know what we were going to be working with. Here is the best description I can give. We ordered the following from Insulation4Less. They told us the lead time was about 4-6 weeks (nationwide shortage) but actually it all came within a week leaving us with a literal mountain of rockwool to store around site. It was wrapped but needed to be lugged into the house out of the rain. Big job. The 50mm deep packs were orginally intended to go in the ceilings where there were lots of pipes to fit around. We chose RWA45 rather than the more expensive Flexi. Having not seen the Flexi I can't give a really accurate comparison. But the RWA45 is flexible and can be pushed into spaces and compressed a little anyway. And it is cheaper. It is not rigid / solid like Celotex (which I had first thought it might be). Here are some open packs. It is pretty easy to cut using an insulation saw like this. https://www.screwfix.com/p/bahco-insulation-saw-22-560mm/7498k But it does shred easily too. Mask and gloves absolutely essential. The 100mm deep stuff looks like this. So although it comes in these "batts" which have a form to them, you can trim to to the size you need. We are trimming almost everything because the 600mm wide batts don't fit into the 560mm gaps between the 600mm centred studs. But there are plenty of places to stuff the offcuts and the puzzle of how to use every offcut as efficiently as possible is keeping us both amused somewhat. We are fitting this into all the stud walls (internal) and the ground floor ceiling. No need for any insulation on the external walls or top floor ceilings as that has been pumped in by MBC (more of that in another blog). Hubby used our MVHR builders straps to fit up a load in the ceiling. He is now using cheap pallet strapping and a staple gun! It is fair to say that we have been doing this sound insulation on and off now for well over a month. It is a big job. Ceilings harder than the walls. Time consuming. A bit (alot) messy. Requires us to ply the walls first (where ply is needed) and then insulate. For the stud walls that don't need ply we will work as quick as we can in the evenings once the the plasterboarders are on site (due next week) filling in behind them as they plasterboard one side. Going to be a busy week. But progress is satisfying and physically working on our build again is fun.

Hi. We have opened the ceiling in our living room which had previously the ceiling in 2.4m height, with a normal plasterboard and 10cm mineral/glass fibre mix. The outside noise was less, but still noticeable. We now want to use the full space of the pitched roof to create a vaulted ceiling. At the moment the rafters have been strengthened and extended to 20cm depth, from which we have left a 5cm void below the felt under the concrete tiles for air ration and added 15 cm celotex insulation. I understand that celotex is great for the heat insulation and that we overreach building specs with the 15 cm, but that it does not do much against outside noise. As we live on a very busy road we wonder what would be the best way to insulate now the roof sound wise the best / economical way? Our builder wants to put additional 2cm wooden batons now under the rafters to account for uneven areas, not filled with anything and attach the sound plasterboard to them? Will this work, or just create an sound problem? Currently I am looking into two different thickness sized acoustic boards, depending on what is available on the market currently. I read about mass loaded vinyl which is quite expensive, and which seems to be often recommended to add in-between the 2 soundboard plasterboards. And in addition I read about resilient bars, where I wonder if they are ok with the weight of two heavy soundboards, and in addition if they are actually helpful against street noise, as this is rather an airborne noise instead of ground-born, , or am I wrong? Or are they rather for ceilings where a room is used above, and so not what I need? What would you recommend to keep out the road noise please? Kind regards Manfred

My design is moving on and I now have an ICF supplier (wall and slab) (Econekt) and a Structural Engineer is working out all the details, which means I have 3-4 support posts (Steel) within the original internal wall structure, 2 x steel beams and 250mm thick Widespan planks to make up the first floor (8.6m spans). What this means is that all my internal walls can now be anything, ICF / Block / Stud, with no requirements for thermal insulation the question is what will provide me the best sound insulation?

Planning for a busy few weeks, need to push the project on a bit if we are to move in within the next 12 months. Need to order some before the BM shut for Xmas..... spec was for wicked slabs but wondering if 100mm roll would be ok - it would be a lot cheaper.... Is it as effective? What have you used? Any words of wisdom vratefully received!

I'm getting prices in at the moment for plaster-boarding/skimming the house but would like to get some prices for the board in advance to see if I'm potentially being ripped off - we need about 900m2 of the stuff. Are there 'best' places for this or is any local builders' merchant as good as anywhere? Same question applies for the sound insulation for the stud walls.