ABOUT ISOBOARD BENEFITS & ADVANTAGES USES & INSTALLATIONS PHYSICAL PROPERTIES CONTACT ISOBOARD
IsoBoard Installation:
Over Truss Insulation

Over Truss

Over Truss

Click here for the
printable page on

Over Truss Insulation.


Guaranteed Energy Efficiency - Your IsoBoard Reward.
IsoBoard Over Truss Insulation
One of the most cost-effective insulated ceilings is to install IsoBoard as a roof-liner over trusses, beams and rafters.

The board, in addition to providing high levels of thermal insulation, provides a beautiful backdrop to exposed trusses, and can be painted to match as required.


Typical uses for IsoBoard in this application:

Used as a ceiling in domestic homes (affordable and up-market) over exposed beams, trusses and rafters.

Note

Over Truss
IsoBoard can be retro fitted between rafters as per Nail Up Ceiling Guide 1.3

Suggested Bill of Quantity Specification:

"ISOBoard® high density 32-36kg/m3 rigid extruded polystyrene 100% closed cell insulation board of .... mm thickness and 600mm width with 100mm centre grooved surface finish / 600mm edge bevel laid horizontally over trusses / rafters and secured with timber-fix screws through purlins. Secure IsoBoard to truss / rafter with batten / screws with washers between purlins or spacer between roof sheets."

Site Handling Instructions

Store boards flat within original packaging until required.

Boards are to be protected from adverse weather conditions and direct sunlight for the storage period.

Handle and install with care to prevent damage to board edges and exposed surfaces.

Wipe boards with cloth and softened water solution to clean as necessary.

Please contact IsoBoard for any queries with respect to the above.


Over Truss Over Truss

Back to the Top


Application Guide

The recommended over truss installation method for IsoBoard

Truss spacings not to exceed 750mm for minimal deflection.

Fix double-sided tape to truss to prevent boards from moving during the installation process.

Lay IsoBoard horizontally across trusses, ensuring that butt joins if necessary are effected over trusses. Lay additional boards and fit using tongue and groove edge profile.

Place purlins or battens over IsoBoard at required centres and secure with timberfix screws through IsoBoard into truss.

Fit a counter batten between purlins running along the truss or 3 screws with washers per board to secure IsoBoard to rafters and prevent uplift.

If required, a quarter round or similar edging can be secured to the truss beneath the IsoBoard to finish the installation.

A layer of 75mm Fibre Isulation can be laid over the IsoBoard to assist with the damping of weather noise where a steel roof is to be installed.

Lay roof sheeting or roof tiles as normal.

Paint visible face of IsoBoard with two coats of good quality Acrylic PVA.

In the case of small dwellings such as low cost housing designs, where 25mm IsoBoard is laid over rafters, fix a spacer strip of 20 mm over the board under the roof sheet to create an air gap, which assists in achieving the required thermal efficiency values.

Ordering IsoBoard for the over truss application

Stock lengths of 8m, 6m and 4.8m are available in 25mm, 30mm and 40mm thickness. Boards can be supplied cut-to-length by the Regional Distribution Centres. Request a quotation for your requirements.

Always order IsoBoard either edge bevelled or with the 100mm centre-grooved finish for this application.

Boards can be ordered to a specific length up to 8000mm where the order volume exceeds 50 cubic metres. Allow at least twenty working days lead time for supply of board.

Consult your nearest IsoBoard sales office for advice concerning the appropriate thickness of IsoBoard required for your installation.

Schematics

Please click on the thumbnails below to see the detail on the schematics.

 
Figure 1 Figure 2  


Back to the Top