At the Manville facility in Innisfail we manufacture fiberglass insulation. Raw materials used for glass making are stored in silos approximately 18 ft. in diameter and 50ft. high. These silos are constructed of insulated concrete blocks that are installed with no mortar and are held together with steel hoops. The outside and inside surfaces are coated with a thin, brushed on water/cement mixture in several layers. The original and subsequent coatings had a water sealing additive intended to make the coating watertight. Our raw materials are dry granular products which in nearly all cases will take up any moisture present and form into lumps. Both the lumps and the increase in moisture content cause problems in our process.
Soon after the silos were put into service, moisture problems began. Filling of visual cracking and several recoats of the outside failed to stop the water penetration. Each year we randomly test for water tightness by applying a water spray at the top of the silo wall, allowing the water to run down the wall for a minimum of 12 hours. The normal result was darkening of the outside surface followed after a number of hours by darkening of the inside surface starting at the lines of the joints between blocks, and spreading from there. If there is a surface crack on the outside that has not been filled, the migration is quick and usually results in beads of water on the inside.
In the summer of 1987 we were introduced to the Seal-It products and looked at Top Seal as a possible sealant for our silos. Top Seal was applied to an area of one silo wall and a spray test done. The immediate observations were that in the treated areas the water would bead up and run off. The treated areas did not discolour and at the end of the test there was no general discolouration on the inside. Some surface cracks were found as a result of the test. Based on that test we decided to coat all of the silos and did so in the late fall of 1987. Water testing in the spring of 1988 had good results but showed areas that the contractor had missed. The difference in colour of the wetted surfaces made those areas obvious. Water testing in 1989 gave the same good results.
The application of Top Seal has not been an end-all solution to our problems, but it has greatly improved our situation. The Top Seal is not intended to and will not fill cracks. Any visual cracks must be filled with a suitable material. But areas without cracks have remained watertight. Based on the results we have seen up to now and the 10 year warranty you have given us, I feel we have spent our money wisely.