We were given a good price to layover our spider crack laden fiberglass roof with architectural shingles if we have it done in January. It has only one layer and we understand this is permited. I was warned by a roofer that the first layer could buckle further and cause our new roof to lift up and in a strong wind lose some shingles. Was he just trying to get more money for removing the old layer? Also is it a problem to have the roof reshingled in January or February? Should we wait 'till spring?

Roofing in the winter is fine, just slower, you need to be careful bending cap or vallies, and very careful walking aroud up there.

I don`t reccomend doing a lay-over at all. You cannot utilize any of the stepflashing wich is vital to seal the walls, chimney,or pipes. If your home has no stepflashing like a hip roof or cape style home ect.ect. you will still need to see the condition of the roof deck. You will have gaps of air trapped under the new roof where the headlaps build up. Condensation between the two roofs promotes allergy and mold growth,and rust that will decay the nailing. Excessive heat build up in summer will dry the roof out prematurly and promote dry-rot on the decking. No manufacturer will warranty the shingles. There are many more reasons. Arcs are thirty year + shingles and you will not get the full life or protection you deserve. If you live in cold areas, Ice and water protection will fail. I could go on and on but as you see there are far too many reasons you should not, and so few why you should. Make sure you have more than addiquate ventilation.

It`s just not a good idea !! You may end up doing and paying for two roofs throughout the life of one done correctly !!

OddBall !!