Aluminum Soffit installed over Plywood Soffit
Hi,
I’m looking for some expert advice here.
In 2011 I had new soffit, fascia and eavestrough installed. The aluminum soffit was installed over the plywood soffit and the two vents covers were removed leaving 2 holes, front and rear. There were no baffles installed. Over the next few years I had ice damming and thought there was wasn’t enough insulation. So, in 2015 I had R50 blown in insulation installed and the installers added 3 baffles front and back. It was at this time that mould was discovered in the attic.
I contacted the roofing company who came back and cut an additional hole in the rear of the house. According to Canadian (Ontario) code, this was more than was required but I still have no air circulation in the attic. The company has finally offered to provide the labour to resheath and reshingle my roof (I am to provide the materials) but this does not address the air circulation.
Where do I stand on this? Should the plywood soffit have been removed before the aluminum soffit was installed? The roofing company says that they have done what was required by code. Their contract stated that they would provide adequate air ventilation and I say that they have not. How can the insulation be pushed back so that it doesn’t block the vents or baffles? Who would do this work?
Can anyone provide information or have had a similar experience and let me know what the outcome was?
I am not able to do the work myself so any help would be greatly appreciated.
Thanks.
Replies
could be different in canada but "code" allows for vented and un vented attic spaces.
if your roofing contractor is willing to do the work there is at least a partial admittion of fault. this, along with the wording in your contract, may be enough to have more than your labor paid for.
I would also suggest you speak with the insulation contractor, it seems from your description they may have not been carefull blowing the insulation and blocking air flow.
am i understanding you correctly that you only have two vents per side? (front and back)
what size is your roof? this seems like a very small amount of ventilation even for a small house.
you basically want to have enough air flow to your attic in the winter time to keep the bottom side of your roof deck from melting the snow on it.
Unfortunately, this is common problem. Each contractor is just doing a bit, and not looking at the whole roofing system to get things right.
Here is the Ontario Building Code (OBC) requirements; they are available online here http://www.ontario.ca/laws/regulation/120332
The part you are interested is 9.19.1.2 and 9.19.1.3
9.19.1.2 specifies the required vent area, which is the 1/300 of the insulated ceiling area. For a typical suburban house of ~1000 square feet of ceiling, you need a minimum free area of 3.33 sq ft. or 480 sq in. This has to be divided between the roof vent and soffit vent. Perforated aluminum soffit has about 6 sq in of Net Free Area NFA per sq ft of soffit. Roof vents are usually about 50 sq in NFA.
If the area is divided equally between soffit and roof, you will need 40 sq ft of perforated soffit and 5 roof vents. There should be nothing behind the perforated soffit, and the roof vent needs to have a properly sized hole in the roof deck with no obstructions.
The code allows the ratio between soffit and roof vent area to go as far as a 25%/75% split either way as long as the total area is met.
9.19.1.3 specifies the clearances between insullation and roof deck. Required space is 2.5" unless baffles are installed, in which case the clearance drops to 1" . The requirements apply to all areas of the roof.
What should have happened and did not:
The soffit installers should have removed the plywood, or at least cut out the ply in the area where the perforated panels were installed to allow free airflow. They should have caclulated the venting requirements based on what roof vents were installed, and provided soffit venting to meet the minimum OBC requirements.
The insulation installers should have put baffles in every rafter bay.
The roofers should have looked at the soffit venting, and seen there was a problem and advised you. Although not common in Ontario, there are ways to add venting directly at the eaves of the roof deck. Or, you could have called the soffit installers back to have them corrected.
How to fix it:
Your are getting mold in the attic because there is moisture escaping from the heated zone of the house into the attic. You need to stop those leaks by sealing your attic. There are number of articles and videos on the Fine Hombuilding site that explain how to do this https://www.finehomebuilding.com/pages/how-to-air-seal-attic/. (Membership required to see it all). You can also check YouTube or Google. Search for "attic air sealing"
Soffit needs to come down, plywood removed or cut open at vent locations, and soffits installed with required venting.
When roof sheathing is off, install proper insulation baffles in each each rafter bay. Baffles should be sealed to the outside walls seathing to prevent wind blowing through the insualation.
Sheath and single roof, with required number of roof vents.
Things to consider:
Code requirements are minimum. There is lots of evidence that more venting is better. I would double the vent area as a minimum.
Finding someone to do the attic sealing may be a little difficult. No many people do this. Difficult to do if you have a low slope roof, but if the roof sheathing is off, access is much improved.
If you are in snow country, consider something like the Maximum roof ventilator. /www.ventilation-maximum.com/English/product-model303.html. Gets the vent above any snow covering.
Thanks for Info
Hi catmandeux,
You are entirely correct. It appears contractors are only doing the minimum required by code. The roofing contractor has been very quick to point out (twice) that the existing vents were sufficient to provide adequate air flow to the attic. The fact that they covered up 80% of one vent with non perforated soffit didn't bother them at all. And when they came back and cut out another soffit hole, they made sure to indicate that this was more than required.
The insulation installers installed 3 baffles at the front and 3 at the rear as there were no baffles installed previously (photos as proof). However, since they couldn't see any light at the back of the house, they were installed at the same locations at the front. Now, it seems that none of the baffles lined up with the soffit holes.
The list below is what I am asking the contractor to do to rectify the problem:
1 - the insulation is protected from blowing winds and rain so that the R50 value is maintained (this should be a no brainer!)
2 - the instulation is to be pushed back to the exterior wall and retained in place
3 - the insulation be removed from the soffit plywood
4 - a 6" wide hole to be cut the length of the soffit both front and back (should be removed but I will accept this)
5 - any insulation currently on the aluminum soffit be removed
6 - baffles to be installed at every perforated section or at every rafter bay
As far as the attic sealing, the attic opening has an ill fitting cover which I will recut, replace and reseal.
I have no leaking from the bathroom fan but will take a look at the moisture generated from this as well.
Can you think of anything further that I should be asking for? The company has indicated that they will resheath and reshingle the roof "in good faith" and I am to pay for the materials. Any thoughts on where I can get roofing supplies at a good price in Mississauga or Toronto, Ontario?
I really appreciate your time on the first answer and appreciate even more any answer you can provide here.
Thanks.
If they followed the Building Code, you likely would be OK
Hi Virgo
If your contractors had followed the building code, you probably would not have had a problem. They either do not know the building code, or are choosing to ignore it. When they insisted that you had sufficient venting, did they mention how much you required, and how they were going to provide it?
Is the roofer the same contractor that put up the soffit?
I can be more specific on recomendations if I had some more details,
Size of house ( length & width),
Width of soffits
Slope of roof, and if Gable or Hip roof.
type and number of roof vents
How many strips of perforated soffit are currently installed.
Comments on your request to the contractor.
Items 1 & 2 are the same issue. With blown in insulation, some form of dam has to be installed at the wall to stop the insulation falling into the soffits. A piece of rigid foam cut to fit between the rafters and extending up from the outside wall will work well. It should be sealed to the wall, rafters and baffle with caulk or spray foam.
Item 6 is related to 1 & 2. With blown in insulation, baffles are required in every rafter bay. I don't know of any other practical way to keep the insulation away for the roof deck as required by Ontario Building Code Para 9.19.1.3
Item 4 is where you may have a problem. If only a 6" wide strip of the ply is removed, the Net Free Area ( NFA) of the perforated soffits is greately restricted. It may required all of the soffit to be perforated in order to get the required vent area. The plywood should come down, or cut completely away where there are perforated sections.
Attic hatches are a common sources of attic leakage. Build a box around the opening at least a couple of inches higher that the blown in insulation. Add a sealed cover at the top, and a sealed panel at the bottom. Insulate with rigid foam glued on the covers, or cut some Roxul insulation to lightly fit the box (~1/4" smaller) bag that in a heavy duty garabage bag and tape to form an "insulation pillow" These should be loose enough to slide in the box under their own weight, but not drop out past the lower panel retaining lip. Any example of this type of box is here how-to/articles/airtight-attic-access (Requires Membership) or here: http://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/how-insulate-and-air-seal-attic-hatch.
Check around you kitchen range hood exhaust and piping as well. If you have interior soffits or bulkheads above your kitchen cabinets, and your house was built in the 60's or 70's, there will likely be large holes allowing air leakage as well. More information here: http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/ba_airsealing_report.pdf
Regarding a good source of building supplies: I am not familiar with suppliers in your area. Your contractor will probably be able to get it cheaper than you can, and if you are still on reasonalbe terms, may be the best way.
Cheers,
Aluminum Soffit
Hi Catmandeux,
I have attached the full report from BBB to help explain.
The house is approx. 20'x 36' with a regular peaked roof at the half way point. No hip, no gable.
I had the shingles replaced in 2004 by a different company. This is a roofing contractor who was recommended to me to install the soffit, eaves, downspout and fascia. They did not install any baffles when they did the soffit. They used the existing vent openings and did not cut any more. The soffit has four perforated panels, 4 plain ones, then 4 perforated and so on. Across the back of the house, there are about 16 perforated vents. It is the same at the front of the house. In the photo attached 2 perforated vents have been removed to show the vent opening. As you can see the opening is partially covered. The opening on the south west side is about 80% covered.
Question: who should have installed the baffles in the first place? The contractor who installed the soffit or the insulation installers?
If you wouldn't mind, once again, to review the attached as I must provide a response to BBB by Sept. 26th and want to have my facts straight.
BTW - are you a roofing contractor or just a very knowledgeable person? The information you have been providing makes me think that youy are working in the industry. Correct??????
Thanks again for your help.
Understand that the venting was probably inadequate, by current standards, even before the new soffit was installed. The installer should have added additional venting as needed to bring thing up to code, at a bare minimum. (This work would almost always be required when intstalling the Al soffit, since it cuts airflow through existing vents in half, and the existing vents were, at best, bare minimum.) And, at a bare minimum, baffles should have been installed at that time that new openings were cut, to fend off any existing insulation.
The insulation installer similarly should have assured that proper baffles were in place around all openings before installing any more insulation.
Unfortunately, the average homeowner is at the mercy of unscrupulous (or just lazy/incompetent) contractors. It helps immensely if you research such issues BEFORE you contract to have the work done, and make sure the contract specifies the necessary details.
Understand that the venting
Hi Dan,
Thanks for the reply.
My contract with the company gives me a 10 year workmanship warranty on "cutting holes in plywood soffit for proper attic ventilaltion."
Although eveything they have done is to "code", they have not provided adequate ventilation.
I understand the importance of researching work being done but you would expect that a "professional" would know what to do and how to do it properly. Boy, am I ever getting an education now! And, unfortunately, I think most of the houses on my street will have the same mold issue as about 95% of them have had new soffits installed and my speculation is that none of them had the plywood soffit removed unless they have construction background or general knowledge of how things should be done.
In defense of the insulation installers, they installed 3 baffles at the front of the house where they could see light coming through the soffit. In the rear, they couldn't see any light and surmised that the holes should be in approximately the same position. There were no baffles initially installed by the roofing company (picture attached)
They were close but part of the vent opening has been covered by the solid soffit sections at one end and almost completely covered by the solid soffit at the other end.
What would you do in my situation? Have them redo the job at their expense? Right at the moment, they are taking the stance that they have done everything correctly and that "in good faith", they will resheath and reshingle the roof providing I supply the materials. I maintain that all of these problems have come from them not providing adequate ventilation.
Is it time to take them to court?
Any thoughts/suggestions would be extrememly helpful as I think I am in an uphill battle.
Thanks.
Hi Virgo.
I read your BBB complaint.
Your contractor's arthimetic is a little off. For the roof vents, 50 sq in x 4 vents = 1.39 sq ft. For the soffit vents, the calculation is only valid if the vent screens were removed and an unobstructed open hole was left. If the screens were left in, the Net Free Area is only 1/3 to 1/4 of the size of vent. I think you were below the current building code requirements to start, but that should have been fixed when the new soffits were installed.
The number of perforated soffits panels installed should have been enough if they were installed correctly. The problem occured because the soffit installer did not cut out the ply behind the ventilated panels. Because the soffit panels are installed very close to or tight to the plywood, the air cannot make its way to the exisiting vents. Net Free Area means just as it reads: wide open space with no obstructions.
I think most of the airflow was obstructed, and that is what triggered the ice daming and mold issues.
To your specific questions;
Baffles are normally installed by the insulation crew, or someone who is tasked with sealing the attic and preparing for insulation. Not normally done by eavestrough / fascia / soffit installers.
You may want to talk with your insulation installer as well. They should have installed baffles in every bay, not just where they thought the vent was. Show them my original response, with the reference to the OBC. If you are having the roof sheathing replaced, it would be the perfect time for them to come back and finish it properly.
I think you are being reasonable with the BBB complaint. The problems were triggered with a bad soffit installation that cut off the airflow and thus did not comply with building code requirements.
My qualifications? Professional Engineer by day, Amateur renovater for family and friends on weekends. Had to read the building code a few times. Not a contractor, but I have shingled a few roofs.
Additional thoughts: There really should be no air exchange between the attic and the rest of the house. If you were being affected by mold that was growing in the attic space, there is something that is pulling attic air into your home. Those leaks should be closed off. Will save you some money on the heating / cooling costs as well.
Good Luck. Cheers
Response to BBB
Hi Catmandeux and DanH,
Just wanted to thank you for all of your information and let you know that I have sent my rebuttal to the BBB asking that the contractor fix the ventilation problem before the roof is resheathed and reshingled.
I don't expect that they will do any of it at their cost but, nonetheless, t appreciate all of your time and effort providing very valuable information.
Catmandeux - Your information regarding the attic cover sealing was great and, as I am handy with saw and hammer, I think I can make my own air-tight seal both at the insulation level in the attic and at the attic access opening. Wish me luck with this. LOL
Again, much appreciate all of your info. Keep up the good work.