Most roofing systems are built on top of a metal deck structure that supports the rest of the system. Sometimes, when construction crews are performing a reroofing job, they tear out the roofing system and find that the metal deck below has become corroded or otherwise damaged. The crew now has to identify the type of metal deck replacement they need and find a supplier who can provide the metal deck in a timely manner. Otherwise, their project will come to a screeching halt.
Fortunately, it’s much easier to find the right metal deck replacement than it was in previous years, as many suppliers have a wide variety of metal deck in stock.
At CSM, we manufacture and stock deck that can be quickly shipped in case of emergencies like these. In this post, we will talk about how to inspect an existing metal roof deck for damage and identify what type of deck it is.
Inspecting Metal Roof Deck
It is important to start a metal deck inspection with as much information as possible. Contact building owners and facility managers to find out about any previous leaks or integrity issues in the roofing system. Try to obtain original plans and drawings of the building to help identify any changes in the roof.
Whenever possible, perform a visual inspection of the underside of the metal deck. In large warehouses and other industrial spaces, the deck is usually left exposed, but for office buildings or residential spaces, the metal deck is not typically visible.
If you are able to perform a visual inspection of the underside of the deck, look for signs of corrosion, structural damage, openings or holes, abrasions, and deformation of the deck. You may be able to determine the severity of the corrosion by hitting the area with a hammer. Any sign of structural damage or corrosion should be marked as a safety hazard and should be barricaded off on the roof.
If the metal deck is painted, you may need a lift or ladder to get an accurate visual inspection.
You will also need to inspect the roof system on top of the building. One way to find metal deck damage on top of the building is by using core cuts, which are common in roofing projects. Expanding the existing core cut will help you determine whether there is corrosion on the metal deck, and how extensive it might be.
Identifying Metal Roof Deck
There a number of different types of metal roof deck. In some cases, the type of deck will be noted on the original plans. If the deck type has not been noted on the plans, you will have to determine the type, gauge, and finish yourself.
The type of deck is based on the deck’s profile. Each deck type is notated by a letter (A, B, N, F, for example). The profiles all have different measurements, which will help you identify which type you have. The easiest way to measure a deck is to measure the gaps in the top ribs.
In this example diagram below of B deck, the gap in the top ribs is 2.5 inches. This measurement is unique to the B Deck profile.
If the top rib is not visible, you can identify the type of deck by measuring the top flange. In our B Deck example, that measurement is 3.5 inches.
In some cases, the type of metal deck may no longer be in production.
The best way to determine the deck gauge is with a micrometer. A micrometer is a small tool that takes extremely precise measurements. However, if you don’t have a micrometer, ask a deck supplier to help. They may be able to identify and recommend the appropriate gauge by looking at spacing supports and project requirements.
You will typically be able to determine the metal deck finish with a visual inspection. Three of the most common finishes are galvanized G-60, galvanized G-90, and primer painted. If the building is in a harsh, humid or wet environment, it is likely that the deck is galvanized. If the building is not in a harsh or wet environment, it is probably primer painted.
Metal Deck Replacement Options from CSM
CSM was recently able to help a roofing contractor with a metal deck replacement by supplying the project with B Deck. This deck was used to reroof a flat roof system at a warehouse in Houston, Texas.
B Deck is the most common structural roof deck. It is an economical and easy to install choice. As our most popular roof deck, we manufacture and stock B, BI, BV, and BIV types of roof deck in 22, 20, 18, and 16 gauge. We also stock F Deck, N Deck, and 1″ roof deck.
We ship nationwide from our Houston, TX metal deck warehouse. Please contact us to request a custom quote for your metal deck replacements needs.