Roofing Codes
No more than 650 lbs of roofing may be applied to a residential home without a enginering analyas peformed by a professional enginer. 3-tab shingles weigh 210lbs per sq and you can have up to 3 layers of these type shingles.
Roof slopes must be greater than 2/12 slope to alow 36" strip shingles such as 3-tabs, or dimintials. Roofs with a 2/12, to 4/12 do require a additional layer of roofing felt, or a layer of ice, and watter shield under them to to prevent driving rain that may get under the shingles.
Elevations for houses over 7000 ft require ice, and watter under layment at all the eves, and it needs to go at least 2 ft on the inside wall. This simply means it needs to go from the eve of the roof to 2 ft inside the heated part of the home. This helps prevent watter that may back up due to ice build up at the eves.
All roofs in Elpaso County require a class A fire rating. Special concerns are for flat roofs, and some synthetic roofing products.
Asphalt shingles require a mi n if 1/2" to 1" overhang at all edges of the roof.
