Wind Smart technology and JR & Co. help save a client almost $700,000 and prevents 1,083 tons of waste for ending up in the landfill...

Gypsum Deck Removal - Case Study

The following is a real life case study of a food grade facility that had lightweight concrete over the top of a gypsum deck. Due to the age and condition of the modified bitumen the lightweight concrete was completely saturated and the gypsum was flaking.  This is completely unacceptable in this type of facility and need to be fixed as quickly as possible.

Most commercial roofing contractors would recommend a complete tear off and removal of the gypsum and then replacing it with steel decking followed by new taper system and a mechanically fastened single-ply sheet. This is an outdated way of thinking and is not in the best interest of the client.

By embracing an innovative roofing technology know as a wind vented roofing system and allowing for some creative thinking the client was able to save almost $700,000 and dramatically lessen this project’s impact on the environment.

Option # 1 - Complete Tear Off and Replacement (Outdated Thinking for a Commercial Roofing Contractor)

This roof was 123,877 square feet, so to perform a complete tear off and removal it was going to take 8 men approximately 2,477 hours. Just this portion of the project alone comes to $92,910 then if you add that amount to the cost for the new steel decking, new taper system, and roof membrane you are looking at a…

$1,320,927 Grand Total for Tear Off and Replacement!

Then take a moment and consider the amount gypsum waste that this would produce on a project of this size? At 17.5 pounds per square foot times the total square footage of 123,877 you are looking at 2,167,847 pounds or 1,083 TONS of waste. To haul all of this away it would take 154 thirty yard dumpsters.

That's a lot of waste! 

Next up is installation of new steel decking, taper system and the new roof membrane. This portion of the project would take approximately 3,609 hours. When you add that that to the waste removal hours and divide it by 8 men working 50 hour work weeks that brings the length of the project to 15 weeks. That’s almost a 4 month business interruption.

Please note that this business interruption is NOT factored into the price. With a tear off, operations would have to cease in the section that is being worked on throughout the entire project. This is going to throw off the entire production process and would potentially cost the company hundreds of thousands of dollars

Option # 2 - Wind Vented Approach (Innovative and Creative Thinking Commercial Roofing Contractor)

When utilizing a wind vented system the roof is held in place by using negative air pressure that is created by the wind blowing over the top of the building. This low pressure system also causes the moisture in the saturated concrete to vaporize and escape through the strategically placed wind vents which dries out and restores it.

There is still the immediate issue of the gypsum flaking into the building. This is where the creative thinking comes into play. By using a spray polyurethane closed cell foam on the underneath side of the gypsum a water tight, monolithic vapor barrier was created. This not only strengthens the entire structure, but also adds an R value of 10 R’s per inch of SPF.

The time taken to apply the SPF and install the wind vented roof system was approximately 782 hours. Using the same math as before we come to a project length of just under 2 weeks. This is huge benefit in terms of business interruption.

Cost for Installation of Wind Vented Roof System - $331,823 + Cost for SPF Application $289,835 = Grand Total of $621,677  which is a Total Savings of $699,250

Side by side comparison between both options

As you can see from all of the data above, there are numerous advantages to using a wind vented roofing system and working with a company that is not stuck in an outdated mode of thinking. With a savings of $699,250 and reducing the impact on the environment by 1,083 tons there isn’t really much of a contest between to two options. Not to mention, the unknown loss of profit from the lengthy business interruption due to the tear off process.