Material Options
flyfisher
Fri Aug 26, 2005 8:45 pm
I need my shake roof replaced and have decided on comp. I've gotten 2 bids (2 others not responsive so I'm at 2 right now). One bid is 2/3rds the amount of the other and I'm trying to figure out what he's missed. In looking over the Scopes of Work, there are some material differences and I'm wondering how they compare. They are both bidding Certainteed Landmark TL, so that shouldn't be the issue. It's a gambrel roof (barn-like) with an overhang extending about 6' out from the house around the entire perimeter. Approx. 5000 sqft in the Seattle area.
Questions:
Is there a significant performance difference between TG2 underlayment and 30-lb felt?
Is D-type flashing significantly better than drip edge and is there much cost difference?
Is it important to flash the gable ends? Both the steep and lower-sloped portions?
If a starter course is not specified, will it likely be left out?
Is CoraVent a good ventilation approach? Does comp. require more ventilation than shakes?
For an existing skylight, is it necessary to detach and reset the skylight in order to do a good job with the flashing?
The more expensive quote specs "APA rated" half-inch CDX plywood sheating while the other does not - does this have some magic in it, is it expensive or are both products probably the same?
The lesser bid does not provide quantities (sqft, linft, etc) - should I be worried? There is a clause covering "unforeseen carpentry work or materials needed which are discovered during the process of scope of work" will be extra. That's fair for things that are hidden, but in my mind, he had the same access to everything that the other bidder had and shouldn't be able to come back with add-ons to cover material shortages.
Thanks in advance to anyone who is willing to address these issues.
Questions:
Is there a significant performance difference between TG2 underlayment and 30-lb felt?
Is D-type flashing significantly better than drip edge and is there much cost difference?
Is it important to flash the gable ends? Both the steep and lower-sloped portions?
If a starter course is not specified, will it likely be left out?
Is CoraVent a good ventilation approach? Does comp. require more ventilation than shakes?
For an existing skylight, is it necessary to detach and reset the skylight in order to do a good job with the flashing?
The more expensive quote specs "APA rated" half-inch CDX plywood sheating while the other does not - does this have some magic in it, is it expensive or are both products probably the same?
The lesser bid does not provide quantities (sqft, linft, etc) - should I be worried? There is a clause covering "unforeseen carpentry work or materials needed which are discovered during the process of scope of work" will be extra. That's fair for things that are hidden, but in my mind, he had the same access to everything that the other bidder had and shouldn't be able to come back with add-ons to cover material shortages.
Thanks in advance to anyone who is willing to address these issues.
QRFL
Fri Aug 26, 2005 9:01 pm
tg2 underlayment is better , but is mainly used in concrete tile roofs...i never use it on comp. 30# should be fine as long as its over 4/12 pitch
drip edge metal is the standar flashing for the perimeter of the roof.
everything in a proper re-roof must be re-flash pipes ,etc.
starter course is standar installation i dont specify it in my contracts
comp does require more ventilation than shakes.. before your atticc could breath thru the shakes not its completely closed, cobra vent is so-so i ve heard good things about ridge vent 2, ask him to switch it.
you munst lift and reset the skylight to flash it right , must be curve mount.
1/2 inch plywood should be fine just make sure to get a city inspection.
carpentry cannot be determined 100% until roof is removed
good luck ,god bless
drip edge metal is the standar flashing for the perimeter of the roof.
everything in a proper re-roof must be re-flash pipes ,etc.
starter course is standar installation i dont specify it in my contracts
comp does require more ventilation than shakes.. before your atticc could breath thru the shakes not its completely closed, cobra vent is so-so i ve heard good things about ridge vent 2, ask him to switch it.
you munst lift and reset the skylight to flash it right , must be curve mount.
1/2 inch plywood should be fine just make sure to get a city inspection.
carpentry cannot be determined 100% until roof is removed
good luck ,god bless
