Passive first Blog

Intumescent Mastic

Tuesday, April 19, 2016

In recent months I have had the opportunity of inspecting a number of newly completed buildings in Sydney. From this, I’ve seen a dramatic increase in the use of intumescent mastic, generally black in colour, that has test approvals protecting plastic pipes. It appears this system has proven itself a success to the end user as it is cheaper than installing a retro-fit or in-wall type fire collar.

When using intumescent mastic to protect plastic pipes it is critical to use the manufacturers specified depth and width in order to comply with the Australian Standards for this product. If the end user is not clear on this, has not read the data sheet, test approval, or does not heed advice from professionals, achieving compliance becomes almost impossible.

Below are some examples of intumescent mastic not meeting approvals.

Case 1 – Intumescent mastic sealing a black plastic pipe. It does not meet the standards as it is also sealing a red cable and is hard against another fire collar that is protecting insulated copper pipes. Another solution is needed to meet the standards.

Case 2 - This penetration contains 3 x black plastic pipes sealed with intumescent mastic. This is hard up against another fire collar protecting insulated copper pipes, therefore this does not meet the standards and intumescent mastic is not the right solution in this case.  

Case 3 - Intumescent mastic barely covers the opening around this plastic pipe penetration. In this case intumescent mastic can be used however, this would not meet standards as the correct width and depth have not been applied. 

While intumescent mastic could be used effectively in some situations, proceed with caution! Incorrect use will result in any number of issues later down the track, ranging from project delays, extra costs, even litigation while it is removed and replaced with a fire stop system that will achieve compliance with the Australian Standards.  

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