Our new home is a 2-story, 100+ year old farm house near the north shore of Lake Erie. It’s about 100km south of our previous home on Lake Ontario.
The house has no attic insulation nor roof vents and that, except for a few almost new homes, practically none of houses in the area have vents.
We are going to insulate but wonder about putting in roof vents, soffit vents and insulation baffles. We do get ice dams which doesn’t surprise because of the lack of insulation. We see far more edge wiring than vents around the area.
I’ve owned several homes but never had a house without a roof venting system but almost no one else seems to use them. Any comments would be appreciated.
Replies
If it ain't broke, don't fix it. Roof venting is at best a dicey solution to either moisture or heat issues. I'd air seal the attic floor, making sure there were no open holes around pipes, wires, or the chimney (do that bit with sheet metal, not expanding foam), insulate with as much blown in cellulose as I could afford, then sit back for a year or so and see what happens. I bet that takes care of any ice dams. Do be sure, however, that there is no active knob and tube wiring, and that any recessed lights have air tight boxes made from drywall surrounding them.
Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
Thanks Andy,
Your suggestion was one of my options . And even if it doesn't work I have the vents to fall back on.
What is your roof like? My 100 year old home has wood shingles and I did not install vents with the last roof I installed (wood shingles no tarpaper). I feel there is enough natural ventilation. The old roofs, fascia and soffits let alot more air pass through than plywood, tarpaper and asphalt shingles. I have 8" of tight blown cellulose in the attic under the floor boards. It's a great place to store stuff because it's so dry( unlike the basement). But you have to keep things covered because things get fine dirt on them. I would like ventilation for the summer to reduce heat build up. While there is no insulation look closely for open stud cavities. Seal with stryofoam and foam. Use metal around the chimney and high temp silicone. Most silicone is good to 400 degrees and if your brick chimney gets that hot your're in trouble.
I'm finishing my roof project currently, and decided against ventilation after researching this for a while. You will find just as many die hard ventilated attic people as sealed / insulated attic people. My house is about 80 years old, and was never ventillated. All framing was in rather good shape considering the age. Any damage seemed to be from flaws in flashing around the chimney and vent stacks. My attic used to get a light coat of frost on the underside of the roof occasionally, but it doesn't appear to have caused noticable damage.
Anyway I had to reroof my home, and have gone with a sealed and insulated roof, as I have vaulted the ceiling in one room, and intend to do a couple more. I did 2 inch rigid foam on top of the existing roof boards, sheathed over it, and roofing with aluminum Reinke shingles. The roof underside is room by room getting dense packed cellulose. The house is a lot warmer now.
I have a thermal imaging camera, and can see how evenly the heat is held in now, and there is no visible moisture problem yet. I could have added air channels and ridge vents, but decided against it due to the added complexity, and chance of water getting in through the vents.
I'm quite sure that there are as many people thinking that this will be a moisture disaster in the future, as there are people thinking that this is how it should be done. You will have to decide for yourself, and possibly be a test case for your area. See what your local codes allow, and your budget allows. Also if you intend to use asphalt shingles you may need to have ventilation for longevity and warranty reasons (or so I've read, so check into that). My roof had been asphalt and appeared to have been only roofed 2 times in 80 years so the actual longevity of asphalt may be fine without the ventillation.
Good luck......