THOMAS Welding Systems SA
B. 6040 JUMET (BELGIUM) Fax : +32
Sales Contact : Email
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  SSP / SIA  -  Insulation fasteners : Choice of system
When fixing insulation boards, sheets, lagging, blocks, mattresses, blankets, quilts, etc..., it is very important that a good mechanical joint is made with the surface to be insulated. Sometimes glue is used but there is a risk that the insulation media will delaminate and the resulting damage will reduce its effectiveness or cause condensation.
Consequently fastening systems which cater for various thickness and give a proper mechanical relationship between the insulated surface and the external face of the insulation are essential.
These more desirable systems normally consist of pins which pass through the insulation media and are fixed to the insulated surface by welding, riveting, or by adhesives. Usually the insulation is held in place by a fastening clip or locking washer. This washer is of sufficient diameter to give a strong joint and to provide a bearing surface to spread the load so as not to damage the vapour barrier or retardant.
Whichever mechanical system is used it is important that they are positioned for best effect.
Around the edges of the insulation where the risk of delamination is more likely there should be more fixings. Other fixings should be distributed uniformly over the rest of the surface to comply with standards or to meet manufacturers recommendations or guidelines.
The range of mechanical insulation fastening systems from THOMAS WELDING SYSTEMS offers the standard types to suit whichever application you prefer. Characteristics of each type are as follows.
SIA : Spindle Insulation Anchor
Our perforated base anchor are designed to fix efficiently insulation on irregular surface (concrete, wood, etc...). In order to meet all requirements, we supply a wide range of lengths. Perforated base hangers consist of a galvanised steel nail (copper/aluminium on request) firmly mounted on a perforated galvanised steel base.
Our galvanised spring steel fastening clips (locking washers) are supplied with hangers. They ensure a perfect upholding of the insulation.
These clips ensure the insulation is held securely in place on the pins, acting as a locking washer. Nylon safety point covers can be supplied to cover the ends of the nails for site protection of personnel.
SIA perforated base pins
  • Galvanised steel perforated base
    50 x 50 mm
  • Zinc plated steel pins (copper/aluminium on request) diameter 2.7 mm and lengths from 19 to 203 mm


  Fastening clips
  • Galvanised spring steel
  • Bevelled edges
  • Standard outside diameter 30 mm
  • Optional outside diameter 38 mm

Protective nylon cap

  • Nylon safety point cover


Recommended assembly method


Install at ambient temperatures above +10° C on clean surfaces
2. Apply adequate adhesive to the underside of the hanger

3. Position the hanger and press until the adhesive seeps through perforations

4. After 5 minutes, the strength of adherence is sufficient for impaling the insulation on the hangers. Maximum strength of adherence is achieved after 24 hours

5. Secure with CL-2 fastening clips

6. If necessary cover the pin with a protective nylon cap