LittleNipper
Prominent Member
I refurbish property. I ended up renovating two properties on the same street in Winchester about 5 years ago. However, I used two very different techniques for various reasons I won't go into. Both houses were stripped back to brick.
The first house, I used acoustic plasterboard ( the blue stuff ) and dot and dab'ed that onto the brick the other was old-school sand and cement onto the brickwork with a skim of plaster over the top.
All I can say is night and day result. The solid walls were just soooo much better - and all of the studies into acoustics I think prove nice dense thick walls are better than 12.5mm of plasterboard with an air gap behind.
If you have this too... You can solve it, in a day without too much mess.
The actual way you do this is mainly controlled by the interface between your plasterboard on your wall and the floor junction. I would always work on the theory, you don't know and follow this technique - you can change if you can think of better solutions.
1. Above the skirting go along and tap. You should easily hear where there is a hollow gap, which is where there is no adhesive.
2. Make each of these points with pencil. Because I have OCD do it in a straight line, perhaps 20mm above the top of the skirting board.
3. If you find areas that are solid, that is fine. Just mark these areas a little differently. This is where the plasterboard adhesive is.
4. Buy a tube of builders foam (Hand Held Expanding Foam 750ml)
5. Go along and drill holes along this line where you have marked just above the skirting board. Make sure the hole is large enough to get the nozzle from the foam gun into. These holes should be about 100mm to 150mm apart. Don't drill where the wall is solid.
6. Hoover out each hole of debris and ensure the nosal of the foam gun goes into the hole
7. Get a little spray gun and fill with water - just empty out a kitchen surface cleaning bottle or similar
8. Go along and use the foam gun to spray into each hole. You might want to put something down to protect your flooring / skirting
9. Let this go off over night - or until hard. Now, just scrape off anything that has come through the hole... This should be on EVERY hole
10. Go up the wall, perhaps a meter and go left to right and tap. This time trying to find where 'air gaps' are. Mark these. Perhaps at intervals of 300mm
11. Now, get a plastic funnel - you know, the one you ( or wife ) use in the kitchen ( Funnel Set )
12. Measure the small end and get an old drill bit - probably a wood drill bit that is twice this size.
13. For each of the holes you have marked at 1m height about 300mm apart, drill a hole at a 45 degree angle down. Then use you finger to clear the hole and leave essentially an 'air gap'
14. Repeat for all holes
15. Go and buy some bags of kiln dried sand.
16. Then use a small paint scuttle to pour the sand into the funnel, whilst the funnel is stuck into each hole. Keep the funnel about 10mm off the brick wall otherwise the sand will not flow.
17. Go ahead and fill the wall.... You might find that tapping the wall will help. But if you put year ear to the plasterboard you will hear the sand trickling down the wall.
18. THIS IS WHY YOU DRILL THE HOLES AT THE BOTTOM, JUST ABOVE THE SKIRTING AND ENSURE THIS IS A SOLID, FILLED SECTION.
19. Once you have gone along and filled all of the holes - you might need a lot of sand. Push some paper into these holes and then use something like a silk filler ( All Purpose Ready Mixed Filler 1kg Tub ) to plug this hole. Equally, you could use some of the foam. If you are using foam make sure you have two nosals - some don't provide two.
20. Now, go another meter up the wall and repeat.
21. Sand and fill, then paint wall.
As you do this you should be able to tap the wall and you will notice the resonance of the wall has gone... This is because it now has a solid mass behind it.
Only do this on walls that are dot and dab onto brick. Do not do it onto stud walls.
The first house, I used acoustic plasterboard ( the blue stuff ) and dot and dab'ed that onto the brick the other was old-school sand and cement onto the brickwork with a skim of plaster over the top.
All I can say is night and day result. The solid walls were just soooo much better - and all of the studies into acoustics I think prove nice dense thick walls are better than 12.5mm of plasterboard with an air gap behind.
If you have this too... You can solve it, in a day without too much mess.
The actual way you do this is mainly controlled by the interface between your plasterboard on your wall and the floor junction. I would always work on the theory, you don't know and follow this technique - you can change if you can think of better solutions.
1. Above the skirting go along and tap. You should easily hear where there is a hollow gap, which is where there is no adhesive.
2. Make each of these points with pencil. Because I have OCD do it in a straight line, perhaps 20mm above the top of the skirting board.
3. If you find areas that are solid, that is fine. Just mark these areas a little differently. This is where the plasterboard adhesive is.
4. Buy a tube of builders foam (Hand Held Expanding Foam 750ml)
5. Go along and drill holes along this line where you have marked just above the skirting board. Make sure the hole is large enough to get the nozzle from the foam gun into. These holes should be about 100mm to 150mm apart. Don't drill where the wall is solid.
6. Hoover out each hole of debris and ensure the nosal of the foam gun goes into the hole
7. Get a little spray gun and fill with water - just empty out a kitchen surface cleaning bottle or similar
8. Go along and use the foam gun to spray into each hole. You might want to put something down to protect your flooring / skirting
9. Let this go off over night - or until hard. Now, just scrape off anything that has come through the hole... This should be on EVERY hole
10. Go up the wall, perhaps a meter and go left to right and tap. This time trying to find where 'air gaps' are. Mark these. Perhaps at intervals of 300mm
11. Now, get a plastic funnel - you know, the one you ( or wife ) use in the kitchen ( Funnel Set )
12. Measure the small end and get an old drill bit - probably a wood drill bit that is twice this size.
13. For each of the holes you have marked at 1m height about 300mm apart, drill a hole at a 45 degree angle down. Then use you finger to clear the hole and leave essentially an 'air gap'
14. Repeat for all holes
15. Go and buy some bags of kiln dried sand.
16. Then use a small paint scuttle to pour the sand into the funnel, whilst the funnel is stuck into each hole. Keep the funnel about 10mm off the brick wall otherwise the sand will not flow.
17. Go ahead and fill the wall.... You might find that tapping the wall will help. But if you put year ear to the plasterboard you will hear the sand trickling down the wall.
18. THIS IS WHY YOU DRILL THE HOLES AT THE BOTTOM, JUST ABOVE THE SKIRTING AND ENSURE THIS IS A SOLID, FILLED SECTION.
19. Once you have gone along and filled all of the holes - you might need a lot of sand. Push some paper into these holes and then use something like a silk filler ( All Purpose Ready Mixed Filler 1kg Tub ) to plug this hole. Equally, you could use some of the foam. If you are using foam make sure you have two nosals - some don't provide two.
20. Now, go another meter up the wall and repeat.
21. Sand and fill, then paint wall.
As you do this you should be able to tap the wall and you will notice the resonance of the wall has gone... This is because it now has a solid mass behind it.
Only do this on walls that are dot and dab onto brick. Do not do it onto stud walls.
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