Insulating floor of a first floor bedroom...airbrick

[curvy1977]

Hi, I've a spare room which sits above the bathroom which i would eventually like to get habitable in order to get a lodger into it.

It is very cold (two external solid walls) but noise from the kitchen travels too easily into that bedroom. I've had guests (very nice guests!) who've told me that 1. the boiler sounds incredibly loud in the bedroom and "if I was a paying lodger I'd not stay in there" and 2. that the tumble dryer which I'd put on before bed was so loud that it kept a guest awake, though it wouldn't have helped that I had dryer balls in at the time.

Anywho, I plan to eventually lift the floorboards, install a mesh net between the joists and put some extra insulation down before using chipboard floorboards as a replacement floor.

But (and it could account for just how cold that bedroom now feels given that the skirting boards aren't fitted and a temporary thin carpet has been laid over most of the floor) I've noticed that there is an airbrick on the outside wall of the house. It looks to be around the level of under the floor of that room.

Will this cause any issues with my plan since it's obviously there to prevent a build up of moisture and I'm worried that by insulating the floor I'll stop the flow of air around...

I'm a total DIY n00b learning the hard way (and I'm a girl) so sorry if this seems clear to everybody but me.

 

[freddiemercurystwin]

You could try your method of just adding some better boards and a bit of insulation, you may find it is not enough it really depends on how bad the problem is and how much £££s you have to throw at it. Measuring sound insulation is very difficult thing to quantify it is very individual!

You will need to identify where the air brick is, first floor voids do not need venting. You may well find it is not in the floor void but has been covered over.

Really to sound insulate a floor you could consider looking at fitting a separate ceiling lower than your existing one (ie with an air gap between new and old) with 2 layers of soundboard (dense plasterboard) this can be suspended with new joists spanning between from wall to wall or with a suspended metal frame ceiling hung off resilient bars off the existing floor joists. Between the metal frame or new joists you can insulate with something like Knauf Acoustic Roll.

Above, a T&G board be it chipboard or plywood will be better than normal floor boards (chipboard has a tendency to creak a lot though). A good carpet and underlay will be advantageous too.

What is important in sound insulating is a meticulous attention to sealing up every single possible gap and joint so for instance when you fit the new skirtings the gap between the skirting and floor should be well sealed. Any gaps between the new plasterboard ceiling and the wall should be well sealed, build a plasterboard box around the ceiling light where that is located etc etc etc.

Lastly you just don't use the tumble drier before bedtime, that solves that straight away, its what millions of us do when we have kids and don't want to wake them up at night.

Eliminating sound is one of the most difficult things you can do in an existing property and the results are highly subjective, you will never eliminate things entirely as there will always be transmission through the structure.

 

[curvy1977]

Thanks for all of that advice! I really don't at this stage have lots of money to throw at it so it will have to be low cost to start with. once I get a lodger and some money coming in I'll reassess if the prpblem persists, though i very rarely use the tumble dryer now so that's one less thing to worry about. Lowering the kitchen ceiling is something I want to do (it's artex *yuk*) but due to a high window I don't have a lot of room to play with when i get around to it.