Glass wool insulation (Knauf) between GF & FF - good ide

[KillingTime]

Hi,

(Three questions about insulation.)

I'm in the process of pulling up most of my T&G woodchip floorboards because they've been flooded (not by me).

I've added 170 glass wool (Knauf) insulation on the ground floor, just wondering about the void between the GF ceiling and the FF floor.

1) I suppose it makes sense to insulate this space, but what about the requirement of the insulation to breathe?

The air gets to the GF insulation from below becuase I've suspended it between the joists with perforated plastic.

?????

2) And what about all the electic cables running in this space. I've read other peoples posts on this and the given advice is to lay the cables on top of the insuation, but I can't do this bacause they all run through holes in the joists. Not enough slack to pull the wires up over the instaltion. There's not just one or two cables, there are loads, and they criss cross everywhere.

3) Lastly, is there any advice about making glass wool insulation water proof? Most of the flooding has come from the 1st floor bathrooms. I notice that when they have flooded, the water runs across the top of the plasterboard ceiling below and spreads out while it soaks through.

If this happens again (unlikely as I'm fixing the bathrooms too) the glass wool insulation will soak it up like a sponge. This has to be bad.

How do other people insulate near / under their bathrooms?

Many Thanks.

 

[noseall]

the reason for internal void filling, i.e. stud voids, floor voids is for acoustic insulation, as the ambient temperature should be fairly constant from one room to another. there is no need to let it breathe either for the same reasons mentioned above.

as for flooding, i suggest in future you avoid it completely!

 

[KillingTime]

noseall to the rescue again...

Might be a thought to lay the insulation nearest the bathrooms in a polly sheet (ony a few quid from B&Q - decorating sheet). That way, if the water does reach that far, it will not hit the insulation.

Will avoid insulating under the bathrooms alltogether.

Thanks.

 

[markie]

noseall to the rescue again...

Might be a thought to lay the insulation nearest the bathrooms in a polly sheet (ony a few quid from B&Q - decorating sheet). That way, if the water does reach that far, it will not hit the insulation.

Will avoid insulating under the bathrooms alltogether.

Thanks.

Don't make his head bigger than it already is

 

[markie]

the reason for internal void filling, i.e. stud voids, floor voids is for acoustic insulation, as the ambient temperature should be fairly constant from one room to another. there is no need to let it breathe either for the same reasons mentioned above.

as for flooding, i suggest in future you avoid it completely!

Having said that, on my last job the B,I wanted the stair well walls insulated for noise etc.. etc.. The wall which is part of the stair well is part of a bedroom which has a rad in, so if the rad is on in the b room the temp is greater than the stair-well temp which would cause condensation inside the wall ?

PS I've done loft coversions for 15 years and found no wet patches in walls or floors. I will give an eg, lets say someone floors their loft out on exsisting ceiling joists where the insulation is compressed between ceiling and new chip boards, when ever I've had to lift C.B up which have been down for a number of years there's been no hint of damp/water any where, in tec it sounds right but in real life it's not the same.

PS i've been on the drink so don't take it personally

 

[noseall]

Don't make his head bigger than it already is

it's actually my nose thats too big for my head, hence allnose.