When it comes to synthetic roofing underlayments in warm climates the same rule applies but for different reasons.
How to put ice guard on roof drip edge.
If you are missing a foot cut off smaller strips and overlap them with the first one.
Place a bead of roofing cement along the top edge of the drip edging and press down on the loose shingles.
Fold the upper half of the membrane back on itself to expose the release film on that side.
Ice and water protector needs to be installed directly onto the roof deck after you have placed the drip edge at the eave.
The best way is to install the roof drip edge only along the eaves first then place ice and water barrier in the snowbelt or felt paper underlayment over the drip edge.
Then slip the roof drip edge under the shingles and the tar paper on the eaves.
Water can wick.
Also if the galvanized drip edge ever rusts it is easier to replace when reroofing if it is installed on top of the ice water shield.
Then install regular roofing underlayment tar paper over the top of the drip edge and over the ice barrier and continuing all the way up the roof.
Installing drip edge on your roof.
Begin at a lower corner of roof and position a length of waterguard rain ice parallel to the eave atop the drip edge adhesive side down aligning in the desired position.
The ice and water shield must stick firmly over the top of the drip edge on the soffit edge of the roof.
Install the ice barrier membrane according to the manufacturer s instructions with the drip edge installed on top of the membrane.
If the ice water shield goes down first the plywood is better protected.
To use this method you will need to loosen the lower run of shingles with a putty knife.
With without rain gutters.
If three feet is anywhere near this mark use three feet.
Around roof features like dormers and chimneys you should place ice and water protector below flashing.
The drip edge will be installed over the ice and water protector and other underlayments at roof rake edges you should install ice and water protector before other underlayments including roof felt.
This lets any water that gets on the roof run down the underlayment and over the drip edge.