If the distance from the roof to the ground is 20ft then you would need to use 40ft.
How to temporarily cover a hole in the roof.
Wind can be powerful and damned persistent.
The 2 by 4 should be about 2 feet longer than the tarp width.
Use 1x2 along the perimeter of the tarp and a few nails or screws to hold them in place.
The most popular item used to cover a roof is a tarp.
Of rope for each corner of your home.
A few holes in a roof that needs fixing anyway is pretty cheap insurance.
Screw the 2 by 4 directly into the roof to secure it.
Temporarily screw the rolled end down to the roof with at least two or three screws.
Next on the peak side attach the tarp to the 2 by 4 using cap nails.
On the undamaged side wrap one end of the tarp around the 1 3 furring strip making sure the furring strip extends past each end by 1.
Make sure you get one that is large enough to cover the entire affected area and one that is meant to be used outdoors.
If you have a vent pipe in the way skip to step 5.
Really you don t want to be up on the roof in a storm trying to retrieve your flapping tarp.
Then fold the excess tarp under a few rotations for a tight clean fit.