Loft Insulation and Boarding. Ventilation Question...

[monkeysDIY]

Sorry, Sorry, Sorry
This may be hidden somewhere.... but I cant find the answer!!

I am going to replace my loft insulation and board loft.
Its a traditional trussles style loft so in theory 3 parts.... The centre one I will board. The joists are 100mm deep so I plan to insulate outer parts with 100mm roll in direction of joists then 90degrees with 170mm. In the centre part I will 100mm in joist direction then 90degrees with 2"x2" at width of loft boards. Oh yeah the question...

Should I then go with 50mm roll and place 18mm boards over or leave a 50mm ventilation gap and just board??? Joists are 560mm apart. The 2" batten I guess will help spread load of boxes, suitcases and other junk!

Really appreciate the help.

Get them bills down!

 

[DAZB]

You will notice no benefit at all by leaving a ventilation gap so I would just lay the boards direct on the 2 X 2 with the 50mm insulation infill.

 

[monkeysDIY]

Thank You DazB
Just wanted to make sure I wasn't going to get stale air or a family of mice moved in!!!!
Excellent, well theres sunday from Shed to Loft...... You gotta love Wickes!!!