4 layers of shingles

[Mike Boyd]

Common sense: How long is the longest roofing nail? Even with 3 layers, not much is penetrating the roof sheathing. Most roofers now use staples which are even shorter. Leggett is correct. Properly laid, the outer edge of the roof has two layers. Most use shingles for the bottom row but some cut a roll of roofing in half and roll out the perimeter before starting the shingles. Sagging may be caused by the roof load but usually it is an inadequate roof structure. A rolling sag might be caused by too thin sheathing. It could be a combination of things so an inspection is necessary.

 

[Wendy]

Per code, 2 layers is max in Florida and the IRC.

 

[Mr Rex]

Common sense: How long is the longest roofing nail? Even with 3 layers, not much is penetrating the roof sheathing. Most roofers now use staples which are even shorter. Leggett is correct. Properly laid, the outer edge of the roof has two layers. Most use shingles for the bottom row but some cut a roll of roofing in half and roll out the perimeter before starting the shingles. Sagging may be caused by the roof load but usually it is an inadequate roof structure. A rolling sag might be caused by too thin sheathing. It could be a combination of things so an inspection is necessary.

You can get 3 inch roofing nails. I have a roofing nailer(air gun) that shoots up to 2-3/4 inch coil nails.

 

[RSW]

You can get 3 inch roofing nails. I have a roofing nailer(air gun) that shoots up to 2-3/4 inch coil nails.

I don't think I would want to stand up in that attic. Ouch!

 

[Mr Rex]

The longer nails are usually used for hip and ridge, ridge vents and can be used for installing cement fiber siding when its blind nailed, but the long ones are available.

 

[Ms. Janet]

I don't think I would want to stand up in that attic. Ouch!

 

[Mr Rex]

I use them to create a bed of nails when I get in a Yoga guru mood and need to ummmmmmmmmmm meditate.

 

[Ms. Janet]

They're perfect to use for home acupuncture to calm someone down who JUST WON"T LISTEN!!!!

 

[CURT VAN HOOSER]

[FONT=Verdana, Geneva, Arial, Helvetica, sans-serif]C. Re-Roofing: FHA will accept a maximum of 3 layers of existing roofing. If more than 2 layers exist and repair is necessary, then all old roofing must be removed as part of the re-roofing. (4905.1 REV-1, 2-12)[/FONT]

Actually, 2-12 says "when reroofing is needed for a defective roof, already consisting of three layers of shingles, all old shingles must be removed prior to reroofing.

So...if the inspection reveals the need for reroofing, all layers will need to be removed prior to reroofing. However, if the roof does not need reroofing... I believe there is no issue.

 

[Mr Rex]

Isn't 3 layers more than 2?