Nowadays, if you have an 25 years old or more home, or are building new home, you will encounter a very common decision; should you have conventional wooden truss frame as your roof structure, or using modern Lightweight Steel (LS)?
And as you search the internet, you will find many articles, encouraging you to use LS. However no one state the downside of the LS.
So, this is 5 fact that you should know before your meeting with your roof contractor:
#1 Lightweight Steel is not Always Cheaper Solutions
That’s what most contractor will tell you. However price are highly relative. Sure, Lightweight Steel is cheaper than Wood Frame, Steel Beam, or Concrete, but it is not on all condition
If your home roof has short span (less than 8 meters), LS is a suitable choice. But at longer span, the frame will need certain modification such as strengthen and careful calculation, which at certain point, using LS will be a disadvantage.
So take extra caution with the word “cheaper”
#2 Lightweight Steel is Fast to Install
This is a fact. LS will always be faster to install than other material, except, steel. However, most contractors will do a beginner mistake such as cutting the materials with wrong tools which came into fact number 3
#3 Lightweight Steel is not that Durable
Most Roof contractor will say that LS more durable than traditional wood truss. Is it? Yes, because woods are prone to wood infestation right?
Continuing from fact #2, LS is a metal, and metal will corrode in time. The LS are coated to make it more durable to corrosion.
However, if you cut with wrong tools, you remove the coating and it is exposed. And in 10 years, if it is stood on humid area, the corrosion will spread and weaken some point.
So in conclusion LS is more durable than Wood truss with termites infestation, but less durable than termites-proof wood truss or the area without termites.
#4 Most every Lightweight Steel Contractor don’t know what they are doing
Most LS contractors are opportunist who see that there is rising demand due to . Then they have someone; a worker who have a little experience in roof construction and then work together as roof contractor service.
Most project will have short span (i.e. shorter than 8 meters) and their work will be okay. But on complex problems, they will use guesstimates, not scientific calculations as their base. And this is highly unsafe.
Since they do not know how to calculate, they will heavily use standard tables without understand the concept behind the standard. When they have competitors, they will try to win with reducing the price, and reducing the specs into minimum requirement regardless how unique the project is, sacrificing client safety on longer term.
So when hiring roof contractor, be sure that they can show you the scientific calculation of the roof.
#5 And did you know that Lightweight Steel is not a Steel?
Yes. You heard it right. Even if it has steel as its name, LS is not steel. LS is made from Zinc and Aluminum. It has the same composition with Zincalume Roofing (if you have heard Spandex or Bondek).
As it is not a steel and it is lightweight. Do not think that it is as strong as steel. In fact to hold the same weight, LS will need bigger dimension than wooden or steel.
Bonus – Should you change your Roof into Lightweight Steel Truss Frame?
With that 5 facts, Let us conclude whether you should use LS for your home:
- For new home, use LS with proper calculation. Have your architect or contractor to keep roof pattern simple.
- If your home have termites infestation, change into LS
- If you want to build new home or have existing home which have tropical design with exposed roof frame, you should still wood. If you are using LS, you should change the overall design of your home as well.
- If your home have been around for 20 more years and has no indication of termites, have professional to check your roof condition, make decision based on the inspection. If it still good, you can call pest control to prevent termites instead.
- If your home requires a roof with 10 meters span or more and you are using ceramics or concrete tile as roof cover, you can use LS with proper calculation and work method. Our standard for ceramic and concrete tiles are 80cm per frame with using C75 with 1mm coated finish thickness, while the frame are subject to calculation.
- For rare cases where your home requires a roof with more than 10 meters span, consider using real steel profile.