When installing you can achieve 0.2 U-value with TLX Silver in 100mm rafters by replacing PUR/PIR cross-rafter installation with an additional, second layer of TLX Silver.
Only 80mm of Celotex Tuff-R or Kingspan TP10 is needed if 1F roofing felt is in place. And, only 70mm if a breather membrane is installed.
Complies with Part L by combining the benefits of thin foil
insulation with other insulation materials. Using Thinsulex Silver as a
platform it is possible to build the required U-value using the BRE
U-value calculator. This provides a wide range of options which can be
influenced by rafter thickness and width as well as whether rafters are
partially or completely exposed.
100mm Rafter 0.2 U-Value Examples
TLX Silver below rafters with Celotex 60mm
between rafters and breather membrane above
TLX Silver below rafters with 110mm mineral glass wool
between rafters and breather membraneTLX Silver below 100 rafters with 70mm Celotex
between rafters and iF Felt above
150mm Rafter 0.2 U-Value Examples
TLX Silver below rafters with Celotex 70mm between 150mm
rafters and breather membrane TLX Silver above rafters
with Celotex 60mm between rafters and breather membrane on top
TLX Silver below rafters with 105mm mineral glass wool
between rafters and breather membrane
N.B. Glasswool at 105mm with a 0.032 W/mK Lamba value may not be readily available, but is shown as the
minimum requirement
TLX Silver above rafters with Glasswool 105mm between rafters
and breather membrane.
N.B. Glasswool at 105mm with a 0.032 W/mK Lamba value may not be readily available, but is shown as the
minimum requirement.
General installation guidelines for TLX Silver
Thinsulex can be attached to the rafters by using double
sided tape, glue, staples or nails.
Thinsulex Silver should have a 50mm overlap and be taped along the
entire length of the joint with a self-adhesive aluminium foil tape.
For under rafter applications
Starting at the ridge and working down, unroll Thinsulex
Silver parallel to the eaves.
Cross batten Thinsulex Silver from the ridge downwards with the batten
spacing no greater than 600mm. The cross battens should be a minimum of
25mm thick.
Finally fix the internal foil backed plasterboard to the cross battens.
For over rafter applications
Starting at the eaves and working upwards, unroll Thinsulex
Silver parallel to the eaves.
Fix battens on top and along the line of the rafters.
Install breather membrane over the battens.
Fix the membrane in place with the tile battens.
tiles/slates should be fitted as soon as possible.
When installing additional insulation
PIR/PUR such as Celotex or Kingspan
Install the PUR (with a lambda value of 0.023W/mK) in
accordance with manufacturers"™ instructions for an
unventilated pitched roof, based on a between rafter application.
Retain a 25mm air gap above and below the PUR.
Mineral wool
Place the 100mm thick mineral wool/fibre glass (with a lambda value of
0.044W/mK) in between the rafters and directly on top of the Thinsulex
Silver.
Performance considerations:
As Thinsulex Silver performs as a vapour barrier, it is
advisable to utilise a breather membrane, preferably reflective, in
your roof system. This will eliminate the need for additional
ventilation.
When installing PUR to attain the U-value of 0.16W/m2K a minimum rafter
depth of 150mm is required.
When using insulated plasterboard, a vapour barrier must be
installed.
Manufacturer's details
Contact the manufacturers thermal hotline 01204 674 730 for
technical advice
Web Dynamics Ltd Moss Lane, Blackrod, Bolton, Lancashire BL6 5JB.