14 December 2020
Blog
Part 1: The importance of sealants and fillers in weatherproofing roof built-up systems

To further improve the long-term performance of your Trisobuild® built-up roof system, careful consideration needs also to be given to the type of fasteners, sealants and fillers used to weatherproof and protect the structure against the elements

 

 

Part1 main

 

To further improve the long-term performance of your Trisobuild® built-up system building envelope, careful consideration needs also to be given to the type of fasteners, sealants and fillers used to weatherproof and protect the structure against the elements

 

Sealants and fillers are one of the key components essential to providing adequate weatherproofing protection to avoid damage from moisture and water ingress and preserve the building for many years to come. Simple and effective sealants and fillers, applied at the installation stage to the external weathering and liner profile joints, will provide a metal roof system that is both water resistant and air-tight, whilst complimenting the duration of the system guarantee.

It is critical, consideration is given to sourcing and specifying good quality sealants and profiled fillers to ensure adequate warranty and life expectancy on all joints, openings, end and side laps – after all they need to be versatile enough to provide waterproofing protection to keep out rainwater, snow, hail, wind, moisture, insects, small birds, etc, and at the same time improve energy efficiency.

We work closely with reputable high-end sealant and profiled filler manufacturers who produce specific materials to complement our Trisobuild® systems providing a waterproofing barrier that will protect your roof cladding system for the lifespan of the building.

When laying butyl strip sealants (PIB) attention must be drawn to the following:

  1. Correct storage conditions: Sealants and fillers must not be left overnight or too long in the elements. For example, not left in direct sunlight or outside in freezing conditions for long periods. Store in containers at general room temperature.
  2. All surfaces where strip PIB is laid must be dry, clean and dust free to ensure an adequate bond/seal is made against the substrates.
  3. In wet conditions, the release paper should be removed as soon as possible to ensure it does not absorb moisture. If left too long it will tear and become difficult to remove.

Ensure Tata Steel guidelines for the correct specification of strip PIB sealants are followed (eg, correct size for the application, specification and supply).

The following information has been extracted from our updated  and details the guidance we provide on sealants and fillers for roofing applications. The sealants and fillers we reference are from reputable suppliers and are recommended for use alongside our Trisobuild® systems.

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Roof sealants and fillers

The end laps of the external weathering profile of the Trisobuild® systems require two rows of 6 x 5mm high grade butyl mastic (minimum 25 years guarantee) this generally comes in rolls of 9.6m with 30 rolls per box. Position sealant in straight, unbroken lines, following the profile, taking care to avoid any stretch. Ensure the continuity and the effectiveness of the seal, especially at corners of sheets. The two lines of strip sealant must be placed between the sheets before fixing: one row nominally 10mm from both the sheet ends at the top and bottom of the lap.

The side laps of the external weathering profile should also be sealed with a 6 x 5mm high grade butyl mastic (minimum 25 years guarantee), placed between sheets on the weather side of the under lap crown.

For external weathering black EPDM, MP or Superseal vented profile fillers should be located between the external profile and the cover flashing (ie, ridge and hip positions) to provide continuity of weather seal and to prevent access by insects and small birds. These shaped fillers should be sealed to their base with a run of gun-applied solvent release sealant.

The liner profile should have both the side and end laps sealed. The end laps sealed with a 4mm diameter high grade butyl mastic (minimum 25 years guarantee).

The side lap sealed with a 50 x 1mm high grade butyl mastic (minimum 25 years guarantee) positioned on top of joint.

For liner profile ends at ridges and hips, white EPDM, MP or Superseal small-flute-profile fillers should be located between the profile's internal profile and the internal cover flashing to provide continuity of air seal. These fillers should also be sealed top and bottom on a run of gun-applied solvent-release sealant.

All sealants can be sourced from either:

Premier Sealants (White strip) - T: +44 (0) 1724 864100
EJOT UK Limited (Blue Strip) - T: +44 (0) 1977 687040
SFS intec Ltd, (Pink Strip) - T: +44 (0) 113 208 5500
Brett Martin (Green strip) - T: +44 (0) 24 7660 2022

All fillers can be sourced from either:

Premier Sealants - T: +44 (0) 1724 864100
EJOT UK Limited - T: +44 (0) 1977 687040
Brett Martin - T: +44 (0) 24 7660 2022

Typical fastener layouts

The table below shows typical fastener layouts for roof profiles. More fasteners may need to be included to resist negative wind load forces. It is recommended that you speak to our Technical Department to discuss the specific loading and support structure on your project to ensure that sufficient restraint is being provided:

 

Profile Main Fixings (sheet ends) Main Fixings (intermediate) Side lap fixings
13 1/2 / 3 Every third pitch Every third pitch 450mm centres (1 1/2 laps)
R32 Every other pitch (5 No.) Every other pitch (3 No.) 450mm centres
R35 Every other pitch (6 No.) Every other pitch (4 No.) 450mm centres
R46 Every pitch Every pitch 450mm centres

If this blog has been useful, perhaps you’ll be interest in our next blog which focusses on the importance of sealants and fillers in weatherproofing wall built-up systems

Please contact our Technical Department for further details on sealants and fillers or use our online specification tool to help you create the right specification for the performance that suits the needs of your project. Doing this will give you peace of mind that cladding components are compatible and perform together as a system.

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