KHIA headerKnow-How in Action


Belzona® Extends The Life Of The Roof



General Industry (GIND)



Roof Problem Areas (RPA)


Customer Location:

Great Falls, MT, USA


Application Date:



Application Situation:

Leaking roof.



This roof had leaked for as long as they could remember. One person speculated that it had probably leaked since it had been built, which was 1906. You can see the many protrusions through the roof, making it difficult to seal with conventional roofing products. Currently, the hot-mopped tar on the roof was seriously "alligatored".



Belzona 3111 (Flexible Membrane)

Belzona 3911 (PSC Surface Conditioner)

Belzona 3921 (GSC Surface Conditioner)

Belzona 9311 (Reinforcing Sheet)



Tar and Copper flashing


Application Method:

The power was cut to sections of the roof where we worked. The roof was dry brushed to remove dirt in the alligator cracks. Because the lines below the roof and overhead carried high voltage electricity, we were not allowed to use water. Belzona 3911 was brushed and rolled on all tar areas while Belzona 3921 was applied to the prepared metal bases, insulators and copper flashings around the roof edges. Belzona 9311 was laid out and the first coat of Belzona 3111 was applied with long handle brushes. The second coat was brushed on the same day. The work began at one end of the roof taking 5 days to complete the job. Temperatures were over 100˚F on the roof. It is now 2014 and the roof has been leak free for 28 years. The application was carried out in accordance with Belzona Know-How System Leaflets RPA-1, RPA-6 & RPA-8.


Belzona Facts:

Reroofing with conventional roofing materials would require tearing off the old roofing to start over on the roof deck. Belzona 3111 was easily applied over the existing aged tar, saving half the cost of conventional roofing. The owner was hoping for a ten year life span, which is their normal re-roofing schedule. Protecting the roof for 28 years and still going has saved the owners the cost of re-roofing twice.


Photographs Description

  1. Roof half done, showing the complicated design and many protrusions
  2. Belzona 9311 laid out and brushing on Belzona 3111
  3. &  4.  Completed application
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