I have a customer that wants to shingle over discolored 3 tabs with dimensional shingles. It’s all about the cost, he doesn’t want to pay for a tearoff. My question is what about the different shingle exposure? If i was using 3 tabs, I could just copy what is there, about a 5 inch exposure, I think. Dimensionals are different , aren’t they? I am going to replace the vents, and flashing around the fireplace chimney. New ice and water in the valleys, what do you think.
Thanks in advance, Dennis
Replies
Strip the roof
Do what you can to talk him into a tearoff. A tearoff will alow you to examine and correct any problems from the old roofing
Most dimensionals I work with are a 5 5/8" exposure. If you try to tuck them to the old shingles, you will need more.
Most likely you will end up laying them to the 5 5/8 exposure and ignore the previous layer.
The ice and water won't be as foolproof as it would be adhered to the sheathing.
I would guess if it is all about the money he won't go for it.
Terry
Remind him that a shingle-over job won't look as good, won't last as long (will likely void the shingle warranty), and will be that much more expensive to tear off next time. Plus most home inspectors should spot it and ding the sale price if he sells.
It'sa foolish way to try to save money, unless the current roof is shot and he absolutely can't afford the tearoff. (In which case should be using the cheapest shingles available.)