I’ll be having somebody trim and side a couple of dormers. He was the highest bidder and I trust him very much. He’s as old as the hills and well respected around town. He’ll be starting in the next week or so and I’m responsible for getting material. He left the material selection up to me, having given me a few ideas of what we he could do to make it durable.
I just thought I would post here to get any suggestions before we launch into this. I don’t want to be up on the roof every other year repairing some problem, which is part of the reason I hired the guy I did. I’ll describe what I am thinking in the order the material will go up.
Soffit – 1/2″ AC ply or 1/2″ BC ply – need to price to find out which one. I’m a little concerned about ply being close to the roof plane where the dormer soffit dies into the roof at the ridge (the soffit is 12″). Should I use 4′ of hardipanel or Azek panel and then go to ply once I get far enough off the main roof plane. I had plywood soffits on the house before I tore them off for the remodel and they were in great shape after 40 years, so I don’t think there is any reason not to use it in general.
1×8 Azek fascia – using this on all three sides. The two sides because it will be close to the main roof plane and the front because I’m not hanging gutters on the dormer and it will see some rain coming from the roof.
Self adhesive flashing tape over the corners of the dormer and around all windows. Tar paper applied to the sidewalls (overlapping self adhesive flashing). Azek 5/4×4 corner boards (bottoms held 1″ off the main roof plane). Pre primed wood brickmold trim framing all three windows as one. 3/4″ pre primed SYP between the windows. Azek frieze board applied to top of walls @ soffit (1×4 ripped in half) – using Azek here because it will be very close to the roof plane where the soffit ends at the main roof. Even though it will be buried up under the soffit, I assume it will still see some moisture. Maybe SYP with the end caulked before installation will be good enough?
Sidewall Cedar shingles applied @ 7″ exposure. Shingles are held up off the roof plane 1″ (meaning they overlap the step flashing 1″). Shingles held off the corner boards 1/8″ and gap caulked.
I think that’s about it, oh yeah, write a big check for the work! Seriously, I’m most concerned with detailing the soffit and fascia where it hits the main roof so I don’t have rotting and I don’t leave such a big gap that things move in (like squirrels and bees).
Thanks for the suggestions and don’t worry, I won’t print it off and run out and tell the guy how to do his job. He’s a good guy and will be happy to discuss the details with me.
Thanks MERC.
Replies
why not use pvc brickmold too?
I realize I could do that, but I think the cedar shingles are going to be the weak link up there. Maybe I should switch to hardishingles on the dormer and then I would feel better about going to all PVC trim.
MERC.
(the soffit is 12").
Why not use smooth concrete siding instead of ply, I know it comes in
12" widths, then you don't have to worry about ripping it or rotting.
bottoms held 1" off the main roof plane
I would just lay a 3/4" on the roof deck and start from there instead of
1", maybe that's what you meant, if not it looks better w/3/4" reveal
I wouldn't use any wood up there, use either azek or concrete siding
Then you'll never have to worry about it.
Also Paint it with Sherwin Willians Duration paint
Did you see the post here a couple of days ago about azek cracking
from the extreme cold, if not maybe someone can post a link to
it. I thought it was very intereting and worth checking out
The soffit is actually about 11.5", so it would be a bitch to cut it. But I still might buy 4x8 sheets and go that route. I just figured using 4' of it would minimize the rotting problem and minimize the cutting of the stuff. I'll talk to my installer.
And I did read the "cracked up" Azek thread the other day. I took it to heart and will be careful with it.
MERC.
...I'm most concerned with detailing the soffit and fascia where it hits the main roof so I don't have rotting and I don't leave such a big gap that things move in (like squirrels and bees).
I'm attaching a pic that shows two different ways of roofing a shed dormer. The front of the house has a hip over the dormer cheek; the back of the house has the more conventional plain shed roof.
I like the way the hip looks, and it may help minimize the juncture problem that you're concerned about.
That's an interesting approach to the dormer roof. My roof is already on so it would require some rework and I'm not sure I want to go down that route. I'll stare it at some tomorrow though.
MERC.