It is usually placed on the fourth.
How to install roof jacks.
Roof jacks make it easier to set roofing and increase safety for you by providing stable surface.
Make sure to examine each driven nail and test each roof jack before placing any planking on top.
Each jack has a flat base with a series of nail holes.
How to install roof jacks step 1.
Middle jacks will help when extra material is loaded on the roof or when workers need to walk from spot to spot.
Use a hammer to bend the top edge of the soft lead roof jack down into the vent pipe.
Install middle jacks under planking once they are put down so you can locate the middle for added stability.
Placing the first roof.
The front end of the base goes under the shingle just above it and you drive a 3 inch nail through the hole at that end.
All nails need to be carefully driven fully into a roof rafter to ensure a safe installation.
Ideally you should find the rafter first underneath the sheathing locate by feeling the nails.
Then attach the tool into rafter by driving couple of 16d nails.
Determine placement determine the best place to fasten your first roof jack.