Should there be a cavity between adjoining houses?

[SteveyJack]

Hi all,

As the title says really, I'm currently hacking a new build to bits so I can thread cat6 through the walls and have 2 cables left but they'll be going down the wall attached to the neighbours. To get around the first floor we've had to drill into the cavity either side of the floor and ceiling and thread them that way on the external side but we're not sure if there will be a cavity on the adjoining side.

Basically, do building regs state that there should be a cavity between two houses? If it makes any difference, in the loft on the external side it's thermalite blocks but on the internal side it's just normal breeze block.

Thanks in advance.

 

[SteveyJack]

FYI - I have tried to look at the regs but it's been difficult to find much information.

 

[Aragorn84]

The point of a cavity is to stop moisture bridging across from the external wall to the internal walls. Thus there isnt really any point in having one for the adjoining wall.

Cables should not be run in cavities anyway.

 

[freddiemercurystwin]

Assume you mean brand new ie post 2003?

I don't quite follow your post tbh but it could be solid or it could be cavity, both methods can achieve compliance. You could do some accurate measuring from window reveals to determine the overall width which will probably give you a clue but that may involve getting access inside your neighbours house too.

 

[SteveyJack]

It was completed at the back end of last year so post 2003.

Is there anything in the regs about what the dividing wall should be consisted of? Or can it be either cavity wall or single skin of breeze with plasterboard either side?

As for measuring I can measure from my window to the internal wall as the neighbouring one will be identical, I guess measuring the external distance between the windows minus the internal distance x 2 would give an idea?

 

[freddiemercurystwin]

Yes that's the ides, but I would not trust that your neighbours window setting will be an exact mirror, hence gaining access to measure.

There are dozens of ways to build a compliant separating wall some with a cavity some without. Even determining the thickness may not be that useful.

 

[SteveyJack]

Well piping HD around the house suddenly got more difficult!