Insulating with kingspan under floor joists in basement?

[and1c]

ok guys

Got a query here!
My sister has recently bought a largte terraced house and it has a basement under the first floor. This did have a damp problem however she called a specialist in who did a new DPC and stripped all the manky white lath and plaster off the cellar ceiling, exposing the joists of the rooms above and in turn helping the ventilation.

The damp problem is now resolved however as its wooden floors above I am looking into insulating between the joists with kingspan or a similar product.

Can anyone give me advice on the best way to do it? as there seems to be a minefield of info out there!

eg/
I know an air gap needs to be left above the insulationunder the floorboards, but do I also need to leave a gap at the end of each joist run so air can flow up there? or is that going to creat a cold bridge?

I have seen it before where the whole lot has been covered in shiny reflective sheeting?

Whats the best way to fix the kingpsan between the joists? am I best to use small wooden battens or??

thanks for all advice

 

[freddiemercurystwin]

The insulation should go as high as possible with no gap between the floor boards and the insulation. You can use nails to hold the insulation up as an alternative to battens.

 

[and1c]

The insulation should go as high as possible with no gap between the floor boards and the insulation. You can use nails to hold the insulation up as an alternative to battens.

THanks but that goes counter to what I thought I knew...!!!

can anyone else confirm or add to this advise please?

 

[freddiemercurystwin]

Don't know what you've been reading to get that idea?

http://www.insulateonline.com/index1.htm?floors2.htm~main

 

[and1c]

Don't know what you've been reading to get that idea?

http://www.insulateonline.com/index1.htm?floors2.htm~main[/QUOTE]

Hmm! Thanks freddymercurystwin!!!
That clears things up a lot. I think I was getting confused with insulating cavities with kingspan!

I didnt realise it would be this simple!! bonus

Many thanks for your help

 

[ajrobb]

That clears things up a lot. I think I was getting confused with insulating cavities with kingspan!

I think you might be confused with insulating between rafters.

Kingspan or Celotex will block any ventilation you got from removing the ceiling. I wonder if the local authority building control were happy with exposing the joists in a building with more than 2 storeys. They might insist on the ceiling being replaced.

Anyway, I think it is normal to use mineral wool to insulate under floors as this allows spills to drain.

 

[hotrod]