If you can hear your neighbour’s TV, conversations, or footsteps through a shared wall, you are dealing with a party wall problem. How to Soundproof a party wall in Ireland is one of the most common requests we get, and it comes with a few challenges that a normal internal wall does not have.
This guide covers what makes party walls different, what you can realistically achieve, and the right approach to fix it.
What Is a Party Wall and Why Is It Worse Than a Normal Wall?
A party wall is any wall shared between two separate homes, whether that is a semi-detached house, a terrace, or an apartment. Unlike an internal wall inside your own home, a party wall is structurally connected to your neighbour’s property.
That connection is the problem. Sound and vibration do not just pass through the wall, they travel through the shared structure itself.
Many older Irish party walls were built to a building standard from decades ago, long before modern acoustic requirements existed. Even newer builds can underperform if corners were cut during construction.
This is why party walls often feel like the worst offenders in a house. You are not just hearing noise through plasterboard, you are hearing it through a structure your neighbour’s home is also built into.
Many older Irish party walls were built before Ireland’s Building Regulations Part E set out modern acoustic separation requirements for new builds
Why You Can Only Treat Your Side
This is the part most people do not realise until they start looking into it. You cannot soundproof a party wall from both sides unless you and your neighbour agree to do the work together, which rarely happens in practice.
That means everything has to be done from your side only. The good news is this is still very achievable. You will not get a perfectly silent wall, but you can get a meaningful, noticeable reduction using the right build-up.
It also means thickness matters. Since you only get one shot at the wall, you want to maximise mass and decoupling in the space you have, rather than relying on a single thin layer and hoping for the best.
What Can You Realistically Achieve?
Now to fully soundproof a party wall, be realistic with yourself about expectations here. A party wall treatment will not make the wall soundproof in an absolute sense. What it will do is significantly reduce the volume and clarity of what comes through, turning a loud, clear conversation into a faint murmur, and turning a loud TV into something barely noticeable.
For most households, that is enough to solve the actual problem, which is usually disturbed sleep, lack of privacy, or general day-to-day annoyance rather than total silence.
The Right Approach to Soundproof a Party Wall
The method that works is building up mass and decoupling on your side of the wall, in layers.
Start with a high-density barrier membrane. A heavy, flexible layer like mass loaded vinyl or a self-adhesive option like Tecsound S 100 adds the mass needed to block airborne sound, without taking up much room. If you are dealing with a tight space and cannot afford to lose much wall depth, this is usually the better starting point than bulkier insulation.
From there, board over it with a dense layer such as AM Soundproofing Eco Board, which adds further mass and improves both airborne and impact sound reduction. Combined with the barrier layer underneath, this gives you a proper two-part system rather than relying on a single product to do all the work.
Sealing every gap matters just as much as the products themselves. Sockets, skirting boards, and where the wall meets the floor and ceiling are all weak points. Even a small gap undoes a lot of the benefit of the layers above it.
Soundproofing a Party Wall FAQ
I am renting. Can I still soundproof my party wall?
Yes, with permission from your landlord. Since the work is non-structural and applied as an additional layer rather than altering the existing wall, most landlords are open to it, especially if it is being done well and adds value to the property.
I live in an apartment block. Are there rules around this?
Apartment blocks often have a management company or body corporate with rules around what can be altered, even on internal walls. Always check before starting work. In most cases, adding a layer to your own side of an internal wall is permitted since it does not affect the building’s structure or shared services.
Will this work for noisy neighbours upstairs or downstairs too?
That is a different problem, floor and ceiling soundproofing rather than wall soundproofing, since the noise is travelling vertically rather than through a shared wall. The principles are similar but the products and build-up are different.
How thick will my wall become after treatment?
Depending on the build-up you choose, you are typically adding somewhere between 15mm and 40mm to the wall thickness. Worth factoring in if the room is already tight on space.
Get Advice on Your Party Wall
Every project is different on soundproofing a party wall, depending on age, construction type, and how much space you have to work with. If you are not sure which approach suits your situation, get in touch and the team will talk you through it.
Contact the team on sales@acousticmaterials.ie or call +353 1 201 5746.
