Advice: Internal wall questions...

[Biddle]

Hi,

Possibly a bit of a noob question, can't seem to get to the bottom of this so any advice would be appreciated...

I have a garage, brick built, 19'x8'x7' with a solid concrete base at the bottom of the garden, which I'm going to convert to a home studio for recording etc.

I intend to build a second internal wall out of concrete blocks for insulation.

Firstly, the existing brick wall does not have any damp course - will I need to put a damp course in the new concrete wall, or is this not viable? I have been told I could Blackjack the concrete floor, and 2-3 bricks high on the brick wall - but I'm not sure if this would be effective enough? Basically, I need to know the best approach to keeping any damp out.

Secondly, with regards to insulation, what is the best choice of concrete block? I won't be plastering the inside, it'll just be plasterboard with rock wool - I assume that dense blocks have the most effective insulate properties due to their density - but will the fact that they are concrete cause damp problems in themselves?

All of this needs to be done with a budget in mind, as it's just a hobby.

Any guidance here would be appreciated...

Thanks

 

[Chukka63]

for a DIY budget job i wouldlay 1 course of bricks.bed in 150mm DPC then build your block walls in aerated blocks with ties drilled/screwed into the external wall.then lay a DPM on the floor,lapped with the DPC,then lay a thinly insulated floating floor to cover the vertical DPC.that way you are then damp proof.
ive made no allownace for PP or Building regs.

 

[noseall]

build your block walls in aerated blocks .

Eh up Chuck, read the smallprint.

The guy is building a recording studio!

You are best building the inner leaf out of dense (7n) concrete blocks.

The rest of what Chuck says makes sense though.

 

[Biddle]

for a DIY budget job i wouldlay 1 course of bricks.bed in 150mm DPC then build your block walls in aerated blocks with ties drilled/screwed into the external wall.then lay a DPM on the floor,lapped with the DPC,then lay a thinly insulated floating floor to cover the vertical DPC.that way you are then damp proof.
ive made no allownace for PP or Building regs.

Thanks for the advice - So, just to clarify, are you recommending that I build a brick course on the inside (with a damp course) and then the rest of the wall built from concrete blocks on top of the initial brick course?

 

[Chukka63]

i was confused when he said concrete blocks were good for insulation.

 

[Chukka63]

you may like to install some insulation between existing and new wall.

 

[Deluks]

I won't be plastering the inside, it'll just be plasterboard with rock wool

If you're still here...

Pb and rockwool? the rockwool needs to go between the outer and inner walls, 100mm at least.
Inside you affix pb straight to the blockwork, or better just a thick coat of plaster.
You will need some rockwool to dampen the inside of the room though in the corners and ceilings, but certainly not as an extra cavity on the inside. (If that's what you were implying.)

 

[noseall]

Incidentally, if you do decide to build an internal wall out of dense 7n blocks then you will need a foundation.