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If you opt to put the metal roof atop current roof shingles, it needs to be done in combination with a synthetic underlayment (recommended). This should then be followed up with galvanized steel hat channel (preferred method) or 1” x 2” furring strips.
What can I use for furring strips on a metal roof?
There are two ways to do this – put in firring/nailing (though nails are not used any more for this) strips or purlins (in steel frame construction) on the roof to support it, or place the metal roofing directly on a flat surface like foam insulation board or the roof sheathing (with roof water barrier in the correct Nov 2, 2020.
Do metal roof need furring strips under?
When installing a metal roof over an existing roof, insulate the spaces between the wood strips with rigid insulation to prevent condensation before installing the roofing. You also need to add furring strips. Twenty-four inches is a common spacing of furring strips for a metal roof.
Can you use 1X4 for metal roof?
In most applications over asphalt shingles, our metal can be applied over the old roof using 1X4 or 2X4 stripping. A metal roof must also allow for some overlap on each side of the panels, which will reduce the effective width of the panel.
How far apart do you put furring strips?
If drywall is to be installed on the ceiling, place the furring strips every 16 inches on center. When laying out the furring strip plan, remember that the strips will run perpendicular to the joists.
What should go under a metal roof?
The traditional and most common material used for roof underlayment on a steep-slope metal roof is non-perforated, asphalt-impregnated felt underlayment. There are several types of felt underlayment including both organic reinforced and inorganic reinforced.
Do I need wood under metal roof?
For many applications, a layer of plywood underneath your metal roofing is an unnecessary expense. Boards measuring 1 inches by 4 inches or 2 inches by 4 inches are commonly used for purlins, though never use treated lumber because it will corrode the steel roof and fasteners.
Can you install metal roof over shingles without furring strips?
You should not attach metal to asphalt shingles without furring out the roof first. Install radiant barrier, install 1″X4″ battens, install metal.
Can you put metal roofing on treated lumber?
Pressure treated wood does not work well with metal. The reaction to the chemicals in the wood and copper which is a dissimilar metal cause the metal to rust. It is recommended that you always use untreated pine or spruce stringers to attach the metal to.
Can you put metal roof on plywood?
Metal roofing should not be installed directly over the top of bare plywood. You do not have to install roofing shingles or other roofing material, but a felt sheet over the plywood is the bare minimum. Even without heavy rain, humidity can build up between the metal roofing and the plywood and ruin the wood.
Can purlins be 1×4?
Purlins are non-pressure treated, 1” x 4” x 12′ lumber that is installed on to the roof in a specific layout pattern and screw pattern.
Should a metal roof be installed over battens?
By design, some metal roofs MUST be installed over battens, some MUST NEVER be installed over battens, and some can be installed over battens OR solid decking. So, whichever way you go, it’s important to choose the right product and install it per manufacturer specifications.
How far apart should rafters be on a metal roof?
Both 16 inches and 24 inches are common measurements for rafter spacing.
Should furring strips be vertical or horizontal?
Run the furring strips vertically — the best option. If the furring strips must go on horizontally, find some way to create a 3/8-inch air space between the furring strips and the rigid foam. Use Cor-a-Vent horizontally to facilitate air and moisture movement behind the siding.
Do you need furring strips for drywall?
If you’re hanging drywall on new ceiling joists, you probably won’t need furring strips. Standard drywall panels attach directly to the joists with drywall screws. If the ceiling is old, however, and you don’t want to remove the existing ceiling finish, furring strips can provide a solid base.
What is the best underlayment for a metal roof?
Synthetic underlayment, like Barricade® UDL Select, is better suited for metal roofing than asphalt felt because it provides up to 30 degrees cooler surface than black underlayments. It also has excellent UV protection (up to six months) and offers a 30-year limited warranty.
What type of insulation goes under metal roof?
Property owners choose fiberglass batts because: It’s one of the cheapest and easiest ways to insulate a metal roof. It’s versatile, meaning you can cut it according to your specific needs. You can also either have it placed under the metal roof panels or installed onto an existing roof’s surface.
Can metal roofing be installed over OSB?
No, you do not need to screw into solid lumber (joists, stripping,etc.). As you can see, the thinnest material they recommend is 1/2” (7/16”) OSB board at 9” on center up to 24” on center. Be sure to follow their instructions in order to obtain the warranty.
Can you put metal roofing directly on shingles?
In almost every case, the answer is yes, you can lay down a new metal roof over an existing shingle roof. This is one of the many reasons metal roofs keep growing in popularity – their installation doesn’t require completely tearing off the existing roof, which is a time-consuming and expensive job.
Are purlins required for metal roofing over shingles?
David Keener responds: To answer your first question: Purlins are always a good idea over asphalt shingles, for a couple of reasons. Also, asphalt shingles can be corrosive to metal roofs, so it’s a good idea to separate the two materials.
Is it necessary to remove shingles before installing metal roof?
Metal roofs can be installed over your existing roof without tearing off shingles, provided local building codes allow it. While shingle removal is the preferred route, tear-off is messy and raises the cost of the job.
Can you put galvanized metal on pressure treated wood?
Hot-dip galvanized or stainless steel fasteners, anchors and hardware are recommended by the Preservative Treated Wood Industry for use with treated wood. This has been the position of this industry for years and their position has not changed with the transition to the alternative copper-based products.
