After the original roofing is removed what you will want to do first is look for bad pieces of.
Install metal roofing over plywood.
Be sure the larger edge is laid so that the small edge of the next panel will overlap it.
When using plywood nail it directly to the purlins and screw the metal roofing panels through the plywood into the purlins as instructed by the manufacturer.
In this installation the vapor barrier is installed on the side of the insulation nearest the interior of the building.
Inspect the plywood for damaged areas.
You will use metal roofing screws to secure the metal panels to the sheathing.
If a proper roof inspection isn t done the 1x4 s could be installed over rotten plywood which means the screws could pull out.
Sweep the plywood clean of all dirt and debris with a push broom.
Align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof.
How to apply metal roofing over plywood step 1.
How to install metal roofing over plywood inspect your plywood.
Use your neoprene washer head screws to secure the metal to the sheathing.
Metal roof installation 2 of 6 featuring edco products.
Try to space the screws about 12 inches apart down the entire piece of metal.
Install the roofing screws vertically along each rib in the panel.
Moreover try to ensure that the screws are all aligned evenly.
Make sure that the screws are all aligned evenly as you will be able to see them from the ground if they are.
For exposed fasteners avoid over tightening the fastener.
I was planning on putting plywood over the rafters and cross the rafters with a 2 x4 every 16 to secure the metal roof to.
Place the first screw.
Applying the underlayment and the slip sheet.
In reading online it seems wise to install a vapor barrier over the plywood to prevent condensation from getting adsorbed into the plywood from the steel roof.
But it seems the condensation will affect the 2x4 strapping.
Repair any rotted sections of plywood before installing the metal panels.
Most metal roofs will also require underlayment as well as a slip sheet.
Remove all unused vents pipes and protrusions.