Roof Construction

De_man

hi

i'll be starting the roof very shortly, i was intending to use
T & G boarding (counter battened) to help keep the house that bit warmer?

is it worth the extra couple of grand to do the roof in this way?

Stupid question here but i assume i still have to keep the air gap (50mm)
between the roof insulation and the T & G boards?

Anyone got an opinion on Tegrals "Bretona" natural slate (spanish) or
does anyone have any suggestions, the Welsh Slate (bangor blues) are just too expensive

thanks in advance

Viking House

Are you putting the t&g on the outside or the inside?

Did you consider lining the outside of the roof with softboard? This improves the Decrement Delay, the windchill resistance and the U-value of the roof



When you have a good vapour control membrane on the inside of the roof with all the joints well taped/sealed then you can fill the space between the t&g/softboard and the vapour control membrane with insulation.

De_man

Viking house, thats exactly what i was thinking about,
putting the T & G on the outside, it'll cost a bit
but i reckon it's the only way to go

thankyou

Viking House

Hi De_Man

Great! We use it all the time now, it works perfect. In Scandinavia they say that 1mm of Softboard used in the roof over a 200 mm layer of Rockwool gives the same insulation as 5mm of Rockwool because it stops heated air from been blown out of the Rockwool.

Where are you getting the Softboard and how much per m2?
Is it latex impregnated? What is the pitch of your roof? Are you using an external membrane?