Saltbox roof = drafty

[deko]

Hi, I have an Asymmetric roof which is causing me some real problems with drafts. I believe the Americans would call it a salt box roof, not sure if it goes by that name over here though.

Best way I can explain it is from the front, my roof starts at the 1st floor ceiling level, and at the back it starts at the ground floor ceiling level.
This results in the eaves being at two different levels.

So on a windy day, I get a draft blowing between the ground and first floor. This causes a cold ceiling downstairs and a cold floor upstairs.

My intentions are to pack rigid insulation in between the joists for about a meter or so (probably woodfibre board). However before I start taking up floorboards upstairs, does anyone know if this might cause condensation problems?

If the floors on the first floor were supposed to be ventilated then shouldn't there be air bricks on the opposite side of the house for through flow, like the ground floor has?

Many thanks in advance.
d.

 

[deko]

ok so let me rework that a little

Should I have a breeze blowing through my floor from the eaves at the back, to the wall at the front (effectively a dead end)?

If that was the intention then shouldn't there be airbricks in that wall to let the breeze through?

Note: Due to my roof shape, at the front I have a normal wall with a window, whilst at the back the roof forms the wall as it slopes to the floor. A cupboard has been created in this space.

Thanks
d.

 

[catlad]

It depends how old your property is to weather any thought to insulation was thought about and drafts, just put some rock wool between the joists but leave a gap at the roof slope a couple of inches will do.

 

[deko]

1920's terraced house, council built.

Is this what you mean catlad...?

(left side)
http://www.dspinspections.com/images/AtticVenting3.gif

Looks like a good solution, roof can still recieve ventilation but insulation in joists should stop the breeze coming through under the bedroom floor.

 

[catlad]

Sounds like you have a truncated roof, but yes same principle.

 

[seasickstevie]

I wonder why it's called a saltbox

 

[deko]

A picture is worth a thousand words...

View media item 51417
This is what the house looks like from the back, whilst at the front it's a normal two story.

I've no idea why it's called a saltbox, but whoever thought it was a good idea to put it on my house must have been on some form of white powder at the time