Tectum Deck Replacment : Is It Necessary?


#1

We have Tectum Decks. When a new roof is done most buildings around here are replacing the tectum with plywood.

But we have some that are simply patching and recoating the roofs, and claim that the windage is actually superior with the tectum deck than with replacement plywood.

Can someone comment on the performance of tectum versus plywood in the event of a huricane? Should we replace the decking or keep it?


#2

I can’t say I’ve ever done any testing comparing plywood to Tectum in hurricane conditions, and I’m not aware of anyone else’s studies. With that said I will say that Tectum is basically a cement coated wood fiber, that would certainly allow air to pass through it much easier than plywood. So with regard to the tectum being better to relieve interior negative or positive pressure, I would say that it would be better than plywood. HOWEVER, the roof membrane you install over the tectum will likely make this a moot point, though it is certainly possible to lose the roofing system and not the roof deck in a hurricane. So in the end, I don’t know that it makes a difference, but it could. Then again, understand that most roof systems installed over Tectum utilize a tube-lock or similar fastener, which typically causes damage to the Tectum when removed. If there is also water damage, it may be prudent to replace the Tectum regardless which one withstands hurricane force winds better.

If you decide to go the plywood route, you may want to check out the option of using Densdeck instead of plywood.


#3

and fyi there are replacement panels of tectum available and they come in an assortment of sizes and can be cut witha simple skill saw.
i never agreed with replacing decking with another type i.e. tectum with plywood.


#4

Big question:

How do they attach the plywwod to the purlins? Is there an approved fastener for this?

I believe tectum decks should be ballasted, but I also know that in some hurricane regions, ballast is being eliminated due to projectile/missile damage caused by it in the storms.


#5

They do the plywood iso thing here as well i myself am like roofboss just spend the money for the tec.sometimes it hard to find but it can be had and densdeck great material.


#6

The plywood is screwed in. The girders are metal in this case. One roofer uses a ringshank nail.

It seems to be the same way they attached the tectum originally, only they are using more screws.


#7

I did not understand the term ballasted in reference to attaching tectum.

The dictionary defines it as being “stabalized”?

How does one normally attach tectum?

In our case there is one screw about every 1 foot across the girders on the tectum decks.