General FAQs

Explore our frequently asked questions about the illbruck brand, our products and our solutions here...


What is an impregnated tape?

An open-cell foam, impregnated with a resin which provides weather resistant properties, compressed onto a roll and available in various widths and thicknesses for joint sealing.

Is it necessary to apply a sealant over the top of the tape?

No – the tape is weather resistant to a minimum of 600 Pa (equivalent to 70mph – violent storm category). If a tape is ‘capped’, this will negate the vapour permeability, potentially causing problems due to moisture entrapment, and could also facilitate three-sided adhesion of the sealant by adhering to the face of the tape and preventing movement of the sealant resulting in adhesion failure to the sides of the joint.

How does the tape function?

The resin impregnation and the high level of compression result in a closed cell structure which is highly weather resistant but remains vapour permeable so that any moisture which may be trapped behind can escape as moisture vapour and ensure drying of the joint.

Are impregnated tapes suitable for movement joints?

The tape can accommodate movement across its thickness (joint width) whilst remaining stable within the joint. The level of movement capability is likely to be in excess of typical silicone type sealants.

How do I select the appropriate size of tape?

In order to do this, determine the joint width, and any variation along the length of the joint. Select the tape thickness range which includes the defined tolerances. The tape width is determined by the available depth into the joint but also subject to being at least equivalent to the maximum thickness, eg 15 (tape width)/7 – 12 (tape thickness range); 20/8 – 15; 20/10 – 18, and being located at least 1 – 2mm inside the joint.

What guarantee of performance do illbruck tapes carry?

The premium illbruck impregnated tape, TP600 has a 15 year performance guarantee and also a 10 year insurance backed guarantee* as part of the i3 System. TP600 & TP450 hold BBA accreditation. Subject to correct selection and application, illbruck impregnated tapes have a life expectancy in excess of 25 years. *under the conditions specified by CPG UK

What is a multi-functional tape?

This is an impregnated tape which combines the three functions of weather resistance, thermal and acoustic insulation, and airtightness. When compared to sealing a window perimeter joint using three separate products (see illbruck i3 System), there is a significant time saving, typically 80%. These tapes are wider and usually fit across the full depth of the window frame.

What is the life expectancy of impregnated tapes and how does this compare to silicones?

Impregnated tapes have been in service for over 25 years and hence, that is the minimum predicted service life currently. This compares with silicones on the basis of the correct grade and correct application being used. Silicone is frequently selected inappropriately, and applied without primer and/or backing rod where applicable. There are fewer criteria to satisfy with impregnated tapes. *under the conditions specified by CPG UK.