Can Standing Seam Metal Roofs Be Installed On Purlins?
Can Standing Seam Metal Roofs Be Installed On Purlins?
Standing seam metal roofs are popular for many commercial and industrial buildings. However, before installing one on purlins, there are a few things to consider. First, metal roofing products installed over purlins without decking are available.
However, this might lead to condensation problems. Therefore, decking and underlayment are advisable to ventilate the attic space.
Secondly, standing seam metal roofs are generally more expensive than other roofing options. As such, it is important to weigh the cost vs. the benefits before making a decision.
How Do You Seam A Standing Seam Metal Roof?
Standing seam metal roofs are typically installed one panel at a time, starting with the bottom of the structure.
1. Tear off your old roof.
To get to a clean deck, your old roofing materials must be removed before your new metal roof can be placed. This implies that your roofing professional will remove old roofing materials and take your old shingles off the roof’s decking section by section.
They’ll tear off your old roof in parts, beginning with the end farthest away from the dump trailer. While one staff is taking off debris from section to section, another crew is ensuring that the ripped-off pieces wind up in the dump trailer or the tarped landing zone in your yard.
2. Install lock strips at the rakes and eaves.
The lock strips will be fitted at the eaves and rakes of your roof (the slanting edge of your roof). Your lock strips will be constructed of the same material as your metal panels, in the same color and gauge.
The starting lock strips are ready to be put in after your old roof has been removed. Lock strips are what secure (lock) your standing seam metal panels to the edges of your roof and protect them from flapping in high winds or storms.
3. Put down high-heat ice and water shield.
Your underlayment will be laid once the lock strips are set on the rakes and eaves. Underlayment is often a felt (15 lb, 30 lb, or synthetic) material laid over your decking to protect further.
On the other hand, an underlayment for your standing seam metal roof will be self-adhering, with high-heat ice and a water shield. The ice and water shield must be fitted over the top of the eaves lock strip.
Condensation beneath the ribs will flow down the fascia board behind the lock strip if the lock strip is put over the underlayment. When water begins to flow behind the lock strip, it will create lines down the fascia board, eventually causing it to decay.
It is critical that the underlayment on your standing seam metal roof be fitted over the lock strip.
4. Install your standing seam metal panels.
Your new standing seam metal roof is ready to be fitted once your roof has been laid out to guarantee that all panels are parallel. Before installing the panels, the bottom will be chopped off at the rib so they may be attached to the eaves lock strips.
The ribs (standing seams) on metal panels are normally 12 to 24 inches apart, depending on the length of the panel. The first panel’s rib will be cut and connected to the lock strip at the rakes to start installing the metal panels.
5. Fill in the gap between the standing seam metal panels and the top of your roof.
Following the installation of your panels, a piece of metal flashing must be fitted to fill in the gaps between the ribs of your metal panels and the ridge of your roof. This type of flashing is known as a z-bar.
A Z bar is a Z-shaped piece of metal that is 1/8th of an inch higher than the ribs on your metal panels. This prevents water from entering your metal panels through the rib gaps at the top of your roof.
6. Lock the ridge capping into the Z bar.
After installing the Z bars, your standing seam metal roof will be ready to lock into the ridge capping or transition metal. Ridge capping is the trim added at the roof’s apex where the two slopes meet.
It will be the same type and color as the metal panels on your standing seam metal roof. If your panels are transitioning from a low-slope roof to a higher slope, transition metal will be required instead of the ridge capping.
To guarantee a straight plane across, the transition metal should come down the roof and out 6 inches before locking onto the Z bar. (It also matches the color of your metal roof panels.)
Can You Put A Standing Seam Metal Roof Over The Shingles?
It is possible to put a standing seam metal roof over shingles. However, before starting the project, it is important to check with the local building department to see if they will allow it.
Some areas only allow re-roofing over one layer of shingles, while others allow over two layers. It is important to follow the guidelines set by the building department to ensure that the roof is installed correctly and safely.
How Wide Are Standing Seam Metal Roof Panels?
The width of standing seam metal roof panels can vary depending on the manufacturer, but most panels are between 12” and 18” wide. The most common width is approximately 16”.
These widths allow the panels to be installed quickly and efficiently while still providing high protection from the elements.
Does A Standing Seam Metal Roof Need To Be Vented?
Yes, a standing seam metal roof needs to be vented. All standing seam metal roofs are vented for two reasons: first, to allow for moisture evaporation, and second, to ensure that the lock strip does not come into contact with the shingles.
Additionally, some areas require that all gutters and vents be kept in the same plane on a roof. If you do not vent your standing seam metal roof, the vents will be in a different plane than your gutters.
