It’s almost time for a new roof and I need to make some decisions (and have some questions)
My roof is getting to be ugly, discolored, and wavy. Years of neglect (previous owners!) and improper venting left the attic and roof in rough shape and it’s getting near the end of its life.
I have addressed the venting issues for now, but I may need to make some changes when I re-roof. The first thing I did was duct the bathroom vent to the outside (which was just being dumped into the attic) and air sealed to prevent as much moisture leaking from the conditioned space into the attic. Second, I had a solar-powered attic fan installed. I know that a lot of people are not too fond of them, but it made sense in my particular case. I have no soffits vents and no ridge vent, just two gable vents. Now, the intake vents are the two gables and the exhaust is the 10w solar attic fan.
I don’t know if I can even have soffit vents with the type of roof I have. The overhangs are not straight across and they just don’t look like most overhangs I’ve seen (lthough I don’t know much about this and I could be wrong). If that’s the case, would it not be a good idea to put a ridge vent on my next roof? To my knowledge, gable vents with a ridge vent doesn’t work very well at drying the roof sheathing.
Alternatively, I could close my gable vents and put my solar attic fan on the garage and spray foam up to the roofline for a conditioned or semi conditioned attic.
My house is small and I live in the midwest. Any thoughts or feedback would be great. Thanks.
Replies
Pictures?
A few pictures would help a lot in giving you advice.
Here are several I just took.
Roof from both east and west and some pics of the gable vents and the eaves.
Not commenting on the vent issue...
But it seems to me that you will need to lan to replace a lot of sheathing, from the way it rolls around like a wave on the sea. And be sure to get the flashing right at that "B" exhaust pipe. Looks like it was done by an amature and after the roof was finished. Sides of the flange should be under the shingles, not over them
You need to figure out what the cause of that swale is, on the right end of the shady side photos. It appears that there are some serious framing issues under there, which may be stable enough to not worry about right away, or which may demand some near-term repairs.
Otherwise the roof doesn't appear to be in terrible shape, though it's difficult to evaluate shingle condition or see joist ripples in the sheathing from such photos.
The sort of eaves you have are definitely hard to ventilate. One could drill holes and install circular vents, but there's likely insulation on the other side that would block them. It's the type of thing that would require thought, planning, and, eventually, hard work.
Thanks, Dan.
I am pretty sure that what caused that swale was moisture in the attic. When I moved into the house, the previous owners had the bathroom vent just emptying into the attic. There was some mold up there. I have since corrected that by ducting the fan to the outside. I treated the mold with some spray and it seems to have been taken care of as it has not returned.
Can you guys see why I put the solar attic fan in? It was necessary to do SOMETHING to get some airflow up there. I thought it was better to put it in the roof as opposed to the gable so I have more intake air. I believe that the more intake air you have the less chance it will suck it out of the conditioned space.
I've got some work ahead, whichever way I go. I think it will ultimately be a cost decision. I also don't know ANYONE around here who reroofs using an unvented attic approach. Maybe in a year or two things might be different.
Well, it's hard to tell for sure from the pictures at that angle, but it looks like the swale is fairly substantial -- not just warped sheathing but a joist or two gone punk, perhaps. I'd want to be sure that's taken care of before going much further.
Pics
I agree, pics would help alot. Without free airflow coming from the eaves, you will not get proper ventilation in the attic space. Normal rule of thumb, equal venting areas at the eave and ridge. Where did you hear that people frown on the solar-powered fans, seems like a good idea??
Post pics....
ANY kind of fan that could depressurize the attic and draw the nice air you paid good money to condition out from the dwelling space is bad.
Unconditioned space is just that. It's really OK if your attic is hot - really hot - or cold. As long as your insulation keeps the heat from penetrating the barrier between conditioned and unconditioned all is well.
Alot of people who have a too hot upstairs or ceiling think the solution is to cool off their attic, when the actual solution is to seal and insulate better - and possibly mix the conditioned air more.
As far as solar fans specificly go, I - who bought two - can attest they are a bad investment. Not for the conditioned argument I made above.
Compare a solar fan that costs $250, with a line wired AC fan on a thermostat at $70. That is $180 in electricity you are trying to buy back, and it will never happen during the lifespan of the product.
I agree with a lot of what you said with a few exceptions.
In my case, I thought the fan made sense. I didn't have hardly any ventilation at all (2 small gable end vents) and I would have had to put in ridge and soffit vents (would certainly cost more than the price and labor of having the solar fan put in. I had some mold issues I was worried about, so I wanted to get it ventilated because I wasn't ready yet to re-roof. I had my ceiling to attic floor air sealed. The top plates, plumbing, electrical, chimney all sealed with foam so whatever is being drawn (probably not much from a small, 10 watt fan that only runs when there's sunlight to power it) is mostly (if not all ) coming from the intake (gable) vents.
I agree with you though. Passive ventilation is best. If the situation would have been different, I definitely would have done the ridge and soffit vents. I just made what I thought was the best choice at the time. Now that I might possibly be doing a new roof, I might be putting it on my unattached garage.
Now that we have pictures
Adding vented soffits is probably not a viable solution. I could be done, but will take a lot of work.
You could however add vents to the blocking between the rafter tails to provide inlet air, and vent the ridge when you install the new roof.
I'd look at installing additional insulation prior to the new roof. We have done a couple over the last few years where we pulled a couple of sections of the roof sheathing off to provide access into the attic. It is far easier than trying to move people and materials through the typical attic access, and adds very little to a reroof cost.
Would it be easiest and best just to keep th existing ventilation system I have now with the solar attic fan and the two gable end vents? When the fan isn't sucking air out, the opening still allows air to flow (wouldn't that be the same as a box vent?).
A big part of the reason I want to reroof is the cosmetic aspect. The roof discoloration and the wavyness of it bother us.
Alternatively, wouldn't it be possible to go with an unvented semi conditioned attic? I could close up the gable vents (or replace them with picture windows) and move the solar fan to my garage and spray foam up to the roof line. I reckon the expense for this is high but it may have some other benefits such as more storage space.
What you do depends on how much money you want to spend
If you stay with the attic as unconditioned space, you need to be sure that the venting system provides enough vent area to comply with the building code. Your local building department can tell you how many square feet you need.
The other option since you have damage to the existing sheathing, and want to get rid of the waves tht are in your shathing, would be to seal up the attic, into conditioned space. I'd look at installing foam over the existing sheating, with the new sheating installed over that.
You could insulate with foam board over your existing roof deck line so you wouldn't need venting at all. This would also make your air barrier at the roof deck too.
After removing your existing roofing and deck, you could place FG insulation bats between the rafters, then lay down sheets of foam board over that in 2" layers until you get to R50 - 60 total. Seal the seams tightly, then fur out 1.5" for a ventalation channel to help prevent ice dams. New decking and shingles attach to the furring, furring is attached to the rafters with long screws.
Brand new roof will not stay shiny for long. Your roof must be covered with tall trees or something. If your roof is less than 15 years old, you are throwing away money to get a shiny roof for a few months. Try spraying some shingle cleaner. Do not power wash.
Wavy shingles. May be the framing underneath, or may be inept shingling. Check from attic side to look at the roof frame. The wave looks too gradual to be plywood problem. Looks like whole series of 2x wood is bending. Could be you don't have cross braces between the joists or removed them for attic furnace? Is furnace or something hanging from the joists? Joists can be straightened without removing them, cutting the joist at the bend and sistering with new. Look at the shingle lines from the roof. Are they straight?
Soffit vent thing started with recognition of ice dam problems years ago. If ice dam is not your issue, what you got is good enough. You don't need conditioned attic, just barrier between your conditioned space underneath and the attic, as one post answered. Peeling paint is most likely due to time and t&g material, but I actually prefer vinyl covering to repainting them.
I think you need somebody to advise you on site.